Chapter 5 HOME RANGE and MOVEMENT of INDIVIDUAL 5.1

Chapter 5 HOME RANGE AND MOVEMENT OF INDIVIDUAL

MELITHREPTUS WITH A FOCUS ON SHORT TIME SCALES

5.1 Introduction

Movements of individual birds have received little attention in the ornithological literature. This lack of information on the movements of individual birds is even more surprising when considered against the backdrop of declining bird populations across Australia, and in particular the declining woodland birds of south eastern Australia. The use of current landscapes by birds is being inferred almost solely through survey techniques (e.g. Saunders 1989; Lynch and Saunders 1991; Saunders and de Rebeira 1991; Bentley and Catterall 1997; Mac Nally and Watson 1997; Wilson and Recher 2001; Fischer and Lindenmayer 2002; Mac Nally and Horrocks 2002; Olsen et al. 2003; Westphal et al. 2003). This is particularly true of nectarivore populations whose movements are often inferred from changes in abundance, usually in relation to nectar availability (e.g. Paton 1979; Collins and Briffa 1982; Collins et al. 1984; Collins 1985; Ford and Paton 1985; Paton 1985; Collins and Newland 1986; McFarland 1986c; Pyke and Recher 1988; Pyke et al. 1993; Mac Nally 1995; McGoldrick and Mac Nally 1998; Paton et al. 1999; Mac Nally and Horrocks 2000; Paton et al. 2004b). Work based on changes in abundance usually results in the movements of honeyeaters described in terms of ‘resident’ or ‘nomad’ (e.g. Keast 1968b; Carpenter and Reid 1988; Simpson and Day 1999; Higgins et al. 2001), rather than quantitative measures of home range or life-time range. Further annotation, such as ‘local nomad’ is often included. However, this gives very little detail about the actual scale over which individuals move, information that is essential to the effective management of populations. While most survey work has provided important insights into population movement, inferring use of landscape by populations from detailed knowledge of individuals is likely to provide a different perspective.

One way in which the movements of individual honeyeaters have been investigated is in relation to territory size. Territory has been described as, ‘aggressive behaviour that occurs repeatedly in about the same location with associated submissive behaviour on the part of the individuals or groups to which the aggression is directed (Pyke et al. 1996)‘. The territory concept has been applied mostly to Phylidonyris novaehollandiae

120 in Australia (Paton 1979; Paton and Ford 1983; Paton 1985; McFarland 1986b; Paton 1986a; McFarland 1996; 2002), but few estimates of territory size are available. McFarland (1986b) found feeding territory size of pairs of P. novaehollandiae to be about 528 m2 (0.0528 ha) and single birds to be about 375 m2 (0.0375 ha). Birds also defended breeding territories, although no estimate of size is available (McFarland 2002).

Radio-tracking as a method of determining honeyeater movement was first published in 1987 using radio-tags weighing about 1.5 grams and lasting up to 20 days (O'Connor and Pyke 1987). Since that time only a few studies have examined the movements of honeyeaters using radio-tags (Table 5.1). Of the studies using radiotelemetry techniques on honeyeaters, none have reported on the day to day movements of radio-tagged individuals or the overall home range of the species being investigated. The original study included both P. novaehollandiae and Phylidonyris nigra (White-cheeked Honeyeater) and defined a ‘grid’ home range only. ‘Current resident’ P. novaehollandiae spent 7% and P. nigra 23% of their time off the grid, but this time was not included in ‘grid’ home range estimates (Pyke and O'Connor 1993), presumably greatly underestimating the actual home range area. Movements of translocated Manorina melanocephala (Noisy Miner) were monitored using radio-tags primarily to assess the effects of translocation (Clarke and Schedvin 1997) and unpaired Lichenostomus melanops cassidix (Helmeted Honeyeater) were radio-tagged to determine the nature of their movements, with a particular focus on dispersal (Runciman et al. 1995). In both these cases, the only movement data published was maximum distance from the release site. There have been a few studies which examined home range size in honeyeaters (Table 5.2). The home ranges determined by these studies have all been less than 1 ha, suggesting very limited movement. Also, such a small home range suggests that the effect of fragmentation per se on honeyeaters is unlikely to be great.

Roshier and Reid (2003) define a number of useful terms in describing the movements of individuals and species. Geographic range is the total area over which the species occurs and is reasonably well documented for most Australian birds (e.g. Blakers et al. 1984; Barrett et al. 2003). Life-time range is also a fairly straightforward concept, being the total area over which an individual moves during its lifetime. However, this is

121 poorly known for most species of bush birds, including honeyeaters, with the best, but still very limited, information coming from banding records. Finally, the home range of an individual is defined as, ‘that area traversed by the individual in its normal activities of food gathering, mating, and caring for young’ (Burt 1943; cited by: Samuel and Garton 1985; White and Garrott 1990; Otis and White 1999; Roshier and Reid 2003), and is usually described as a numerical estimate of the area used by an animal (White and Garrott 1990). An important addition to this definition is a timeframe of interest (Otis and White 1999). Other important activities occurring within the home range include breeding, predator evasion, shelter/exposure seeking, play and territory defence (Roshier and Reid 2003). Home range for most Australian bush birds is also poorly known over any timeframe.

The methods of describing home range are many, but a few appear to have been accepted more widely than others. By far the easiest and most widely used is the minimum convex polygon (MCP), which draws a polygon around the locations (fixes) of an animal which surround the greatest area. Their wide use makes them one of the few methods useful for comparison between studies (White and Garrott 1990). A widespread criticism of MCP is that the MCP includes large areas not used by the animal (Kenward 1987; White and Garrott 1990; Kenward et al. 2003). White and Garrott (1990) argue that the word ‘normal’ in the definition of home range is important and that some means of excluding data from excursions outside the ‘normal’ home range is needed during analysis. However, it appears that many animals do undertake excursions, and excluding such data without knowledge of the reasons for undertaking excursions is likely to provide an underestimate of the area needed by the animal. A more valid criticism of MCP is that they give no indication of how intensively different areas of the range are used (Kenward 1987; White and Garrott 1990; Rodgers and Carr 1998; Kenward et al. 2003). Both these criticisms are overcome to some extent by more sophisticated methods of determining home range, such as harmonic mean (Dixon and Chapman 1980) or kernel (Worton 1989) analysis.

This chapter presents data on the movements of individual Melithreptus and P. novaehollandiae, at a number of sites within the Mt Lofty Ranges, with a focus on short time frames (less than a month). Comparisons are made with a focus on differences within the small Melithreptus guild and between Melithreptus and P. novaehollandiae.

122 Radio-tracking was used to determine the movements of individual birds as this method allows data to be collected on where the bird goes, not where the researcher goes, as is commonly the case with other methods (mist-netting, colour-banding).

123 Table 5.1: Summary of radio-tracking studies on Australian honeyeaters

Phylidonyris novaehollandiae and P. nigra results were not distinguished in the studies listed. * Maximum distance moved given only if dispersal occurred, mean given is for three birds which dispersed. Days Distance (km) Species Transmitter weight (grams) Mean Max Mean Max n Study P. novaehollandiae and P. nigra 1.5 – 1.6 2.4 5.3 - - 15 O'Connor and Pyke (1987) P. novaehollandiae and P. nigra 1.5 – 1.6 6.6 - - - 93 Pyke and O'Connor (1993) Lichenostomus melanops cassidix 1.7 – 2.3 32 43 *12.7 20.4 12 Runciman et al. (1995) Manorina melanocephala 2.0 – 2.5 30 51 3.4 5.6 10 Clarke and Schedvin (1997)

Table 5.2: Results of some home range studies on Australian honeyeaters

A – adult. J – juvenile. B – breeding adult in the non-breeding season. N – non-breeding adult in the non-breeding season. HMC is Harmonic Mean Contour. MCP is Minimum Convex Polygon. 1Locations were only used if they were ‘on grid’ – the 90% MCP relates only to those points that were already within the defined grid, ignoring those fixes (number or % not given) that were outside this area. 19 of 93 bird had sufficient information for the analysis. Home range Species Sex Age Type Radio-tagged ha Type % n Study L. melanops cassidix ♂ A B No 0.39 HMC 80 6 ‘Mauve’ site. Moysey (1997) L. melanops cassidix ♀ A B No 0.30 HMC 80 6 ‘Mauve’ site. Moysey (1997) L. melanops cassidix ♂ A B No 0.24 HMC 80 5 ‘Green’ site. Moysey (1997) L. melanops cassidix ♀ A B No 0.21 HMC 80 5 ‘Green’ site. Moysey (1997) L. melanops cassidix ♀&♂ A N No 0.28 HMC 80 5 ‘Green’ site. Moysey (1997) L. melanops cassidix ♀&♂ J No 0.51 HMC 80 4 ‘Green’ site. Moysey (1997) P. novaehollandiae and P. nigra ♀&♂ A Yes 10.48 MCP 90 19 Pyke and O'Connor (1993)

124 5.2 Methods

The movements of Melithreptus were investigated at four sites in the Mt Lofty Ranges: Scott Conservation Park, Kaiser Stuhl Conservation Park, Scott Creek Conservation Park and Newland Head Conservation Park. As the birds rarely confined themselves to the conservation parks these sites are referred to as the ‘areas’ of Scott, Kaiser, Scott Creek and Newland. At each site, Melithreptus were caught with mist-nets, morphological data were collected and the birds were either colour-banded to allow unique identification of individuals in the field, or colour-banded and radio-tagged. The Scott area was chosen for repeat visits throughout the project, while the other three areas were visited for one tracking session (Table 5.3).

Table 5.3: Days per month on which movement data were recorded in each area

Season Month Kaiser Newland Scott Scott Creek All Areas Jan 2 2 Feb 1 27 28 Mar 15 15 Non-breeding Apr 4 44 20 68 May 18 9 27 Jun 10 17 27 Total 1 32 114 20 167 Jul 41 41 Aug 1 13 2 16 Sep 10 15 25 Breeding Oct 25 6 31 Nov 37 37 Dec 18 18 Total 36 130 2 168 Both Seasons Total 37 32 244 22 335

5.2.1 Mist-netting Mist-netting with the aim of catching Melithreptus was not always productive. By far the greatest trap success was during summer and autumn periods, but only when trapping around water (dams). During spring and winter when water was plentiful elsewhere these dams could still be successful on warmer, drier days. At most sites, the dominant vegetation was too high to place mist-nets amongst the canopy, and sites at which Melithreptus were observed lower for some reason were chosen. These included patches of flowering A. pycnantha, low E. viminalis foliage, Callistemon rugulosus and

125 regenerating E. camaldulensis or E. leucoxylon. Trap success in such sites was low and variable.

The predominant use of water as a trap site ensured a ‘random’ sample of birds from within the study areas. A net capture at water was often the furthest record of a bird from its core area. On occasions when birds were caught around vegetation, not water, it was usually within their core area. As a further note, no Melithreptus originally caught within their core area were re-caught in a net at the same (identical) net location. This was true for individuals that were known well, and could be sighted in their core areas over several years, but not re-trapped using the same net locations. As net locations within core areas were often limited, it was especially difficult to re-trap known birds.

5.2.2 Colour-banding All Melithreptus caught in mist-nets were colour-banded. Originally, the aim was to follow colour-banded individuals to determine movements. However, it was soon evident that following colour-banded birds was not an efficient means of determining the movements of Melithreptus. Establishing a systematic survey of the sites at which colour-banding occurred was also not efficient, with several days spent in the field early on, resulting in no records. Despite these limitations, colour-banding provided useful information over the longer term. Throughout the majority of the project, colour-band resights were opportunistic and usually occurred in certain areas known to be frequented by colour-banded individuals (core areas) or while radio-tracking an associated (at least temporarily) individual.

5.2.3 Radio-tracking

5.2.3.1 Radio-tracking trial A trial was run using Bio Telemetry Tracking Australia radio-tags during April 2001. These radio-tags weighed 1.1 – 1.2 grams without a reed switch (which allows a magnet to turn the radio tag on or off), had a battery life of about 12 days and a maximum detection distance of about 300 metres. Due to lack of a reed switch, the Bio Telemetry radio-tags required soldering immediately prior to attachment to the bird. These radio- tags were attached to two M. lunatus caught at Scott Conservation Park dam on the 6th

126 April 2001, an adult male with metal band 026-01621 and colours RMBO and a 1st year female with metal band 026-01605 and colours RMBY.

One of the two Bio Telemetry radio-tags failed sometime between 46 hrs when the bird was last found by radiotelemetry and 68 hrs when the bird was sighted by chance (the colour bands and antenna were clearly seen, but there was no signal). The other radio- tag fell off between 40 hrs 45 mins and 41 hrs 25 mins after deployment. The results of fixes taken during the trial radio-tracking can be seen in Figure 5.1. None of the data collected at this time was used in later home range analyses as there were times during which no signal could be detected from the radio-tags. Originally, this was put down to the radio-tags being unreliable. However, after tracking other birds, it is possible the birds were moving out of the area plotted in Figure 5.1, and these movements were not detected due to the limited range of the Bio Telemetry radio-tags.

The radio-telemetry trial showed that it was possible to radio-tag Melithreptus individuals and find them using radio-telemetry techniques. However, it was necessary to obtain radio-tags with improved detection distance and reliability.

Figure 5.1: Results of trial radio-tracking during April 2001

Two individuals had radio-tags attached in April 2001 to trial the radio-tracking methods. Band 026- 01621 was an adult male (RMBO) and band 026-01605 was a 1st year female (RMBY). The data obtained from this trial were not used elsewhere.

127 5.2.3.2 General radio-tracking methods Birds were caught in mist-nets and were fitted with single stage radio-tags (Titley Model LTM) weighing 0.8 to 0.85 grams (Figure 5.2). Titley LTM radio-tags were fitted with a reed switch (allowing the tags to be turned on and off with a magnet), had a battery life of 26-28 days and a claimed maximum tracking range of 5-6 km. The greatest tracking distance confirmed during this study was 1.1 km. Birds were weighed when captured, and no birds less than 12 grams had radio-tags attached (0.85 grams is 7% of body weight for a 12 gram bird). Radio-tags were attached with superglue to the interscapular region of the back after trimming the feathers of that area to a length of 1- 2 mm (O'Connor and Pyke 1987). After release, birds were located at least once on the first day to ensure they were moving and appeared okay (unhindered by the transmitter). Collection of data started the morning after release.

The Scott area was used throughout the study for radio-tracking, while the Kaiser Stuhl, Scott Creek and Newland Head areas were all used once; Kaiser Stuhl during the breeding season and Scott Creek and Newland Head during the non-breeding season. Numbers of individuals of each species radio-tagged and approximate visit dates to each site are given in Table 5.4. During each visit, up to six birds were radio-tagged at once, although this varied depending on trap success and the length of time radio-tags remained attached to birds.

Birds with radio-tags attached were located sequentially throughout the day. Fixes were taken with a GPS (Garmin eTrex, 12XL or 72) when individuals were sighted, or when a bird was confirmed to be in an individual tree by circling the tree with the signal continually coming from the same spot (attempts were made to find birds in this situation, but it was not always possible to see them). Using a sequential method of finding birds essentially resulted in random time between consecutive fixes on each bird due to the variability in movements of the individuals and ensured a reasonable number of fixes on each individual each day. Additional information recorded for each fix included notes on the weather, plant species and number of other conspecifics detected in the area. Colour-bands on conspecifics in the area were obtained when possible, but this time consuming occupation was only occasionally successful. Collection of behavioural information was an important part of most fixes (Chapter 6).

128 Figure 5.2: Melihreptus lunatus with radio-tag attached

The aerial can be seen sticking out from the radio-tag which has been attached just below the neck on the interscapular region of the back. Despite having a radio-tag recently super-glued to its back, this individual has maintained a sense of humour – sticking its tongue out as its photo was taken.

Table 5.4: Months during which radio-tracking occurred at each site and number of each species tracked during that time

Number of radio-tags attached to: Year M. brevirostris M. lunatus M. gularis P. novaehollandiae Scott April 2001 - 2 - - July-August 2001 4 3 - - February 2002 3 3 - - September 2002 2 - - - November 2002 3 3 1 - April 2003 2 3 - 2 June 2003 - - - 4 Kaiser Stuhl September-October 2001 2 4 - - Scott Creek April 2002 - 4 - - Newland May-June 2002 6 1 - - Total 22 23 1 6

5.2.4 Analysis

5.2.4.1 Home range The radio-tracking data resulted in a number of fixes on an individual. These data were used to estimate the home range of an individual using different methods; overall minimum convex polygon (MCP, always 100%) and kernel density estimates. MCP provides the most basic measure of home range of an individual, being simply the total

129 area enclosed by the outer most fixes. However, few individuals use the landscape within their total home range evenly, so another measure of home range is needed to give an indication of the intensity at which an individual uses the total area available to it, or in other words, to define core areas of use, if they exist. Kernel analysis was used to define these core areas. Besides these overall summaries for an individual, the area used by an individual each day was used to provide an indication of the area used by an individual in order to survive. As the number of fixes on an individual per day was rarely more than about four, 100% MCP was the only viable analysis for these data. These ‘daily’ MCPs were also calculated, when possible, for birds without radio-tags attached. Figure 5.10 (pg 151) provides an example of each of the home range analyses carried out on each radio-tagged bird. Overall MCP and daily MCP were done using the Animal Movement extension for ArcView 3.x (Hooge et al. 1999). Kernel home range analyses were undertaken using Ranges 6 (Kenward et al. 2003). An initial run of analyses was used to determine a mean multiplier of Href (see below), which was then used in the final kernel analysis.

Overall MCP (100%) is a measure of the total area used by each individual, while daily MCP (100%) is a measure of the total area used by an individual each day. Kernel home range (KH) is a measure of how much area the individual is using at different intensities, and therefore was used to define core areas of use. For KH and daily MCP, each is compared to the overall MCP to compare the percent of total area used. Overall MCP, daily MCP and KH at three levels (10, 50 and 90% utilisation distribution, UD) were tested statistically for the effects of season and species/sex of the small Melithreptus guild. Individuals were treated as replicates for each species/sex (Otis and White 1999), ignoring any effects of site (which should be similar between species). Melithreptus gularis was not included in any statistical analyses due to lack of replication. The effects of taxa on each of the home range attributes were tested within the non-breeding season only for Melithreptus and P. novaehollandiae. Data were ln transformed to meet the assumption of normality for ANOVA (Zar 1984), with all data being normal after transformation. The Shapiro-Wilk W test was used to test for normality using JMP IN software (SAS Institute Inc. 1997). ANOVA, t-tests and Tukey tests were also carried out using JMP IN. For Tukey tests, a statistical effect was accepted at α = 0.05. All home range data are presented as the antilog of the ln mean ± standard error.

130 5.2.4.2 Kernel methods Kernel analysis has been demonstrated to produce good estimates of home range size in a variety of circumstances (Worton 1989; 1995; Seaman and Powell 1996). Kernel analysis has the advantage of being able to define area usage more accurately than MCP and also to define multiple cores of activity. The analysis works by placing a kernel, also described as similar to a bell curve (Carr and Rodgers 1998), over each fix in the home range. A grid, placed over the home range, is then used to average all kernels that overlap at each intersection on the grid, providing a kernel density estimate (Seaman and Powell 1996; Carr and Rodgers 1998), which is an estimate of the probability (utilisation distribution, UD) of finding the animal at that point (Worton 1989). The kernel density estimates are then used to produce contours within which an individual spends a percentage of its time. For example, within the 50% contour, an individual is estimated to spend 50% of its time.

There are two issues to consider with the grid used to produce contours; extent and size. As most contours extend beyond the range of the fixes, it is important to extend the grid beyond the range of the fixes. Most software takes care of this (e.g. the fixes span the central 70% of the matrix, or grid, in Kenward et al. 2003), but problems do sometimes occur (such as the contours being cut off at the extent of the grid), in which case the grid may need to be extended further. The size of a grid is not much of an issue for results once it gets bigger than about 50×50 cells, and most software is now capable of using grid sizes up to 120×120 (Carr and Rodgers 1998) or 200×200 (Kenward et al. 2003). A much more important issue than the grid in kernel density estimation is the width of the kernels (Worton 1989; 1995; Seaman and Powell 1996; Carr and Rodgers 1998; Rodgers and Carr 1998; Seaman et al. 1999; Kenward et al. 2003). The kernel width, h, is also referred to as the smoothing factor or parameter, bandwidth and window width. It is a measure of how far away from the fix the ‘bell curve’ extends. The larger h is, the further away from a fix it will extend and the estimate of kernel density at each grid point will be based on a larger number of individual fixes. A large h reveals the general shape of the distribution of fixes, but may result in ‘undersmoothed’ kernel density estimates in which any fine detail contained in the home range fixes may be obscured and centres of activity are unlikely to be clearly defined. Conversely, small h provides a large amount of detail about the distribution of fixes, but may result in ‘oversmoothed’ kernel density estimates as each estimate is only based on a small number of (close by)

131 fixes. Oversmoothed estimates are likely to be highly variable and to provide kernel density estimates too dependent on the current distribution under investigation, making comparisons between individuals less meaningful. Contours generated using a value of h too small wrap tightly around each small cluster of fixes and therefore provide little further information than the original raw fix data.

The optimal kernel width determined analytically for standard bivariate normal distributions is referred to as href and is the standard deviation of rescaled x and y coordinates divided by the sixth root of the number of locations (Worton 1989; Seaman and Powell 1996; Rodgers and Carr 1998). The x and y coordinates are rescaled as it is unusual for an individual to move an equal distance in both the x and y directions (Kenward et al. 2003). However, animal distributions are unlikely to be well represented by a standard bivariate distribution, as animals often have a number of centres of activity, with each centre having a different area and intensity of use. This violates the assumptions of the standard bivariate normal distribution, and kernel density estimates based on href are usually undersmoothed (h too large) (Worton 1989). A more appropriate choice of h for estimating kernel densities of animal distributions is least squares cross validation (lscv). This method examines the resulting kernel density estimates obtained by using numerous values of h, between, say, 0.01×href and 1×href, and attempts to find an optimal value for the given distribution (Worton 1989; Seaman and Powell 1996; Rodgers and Carr 1998; Kenward et al. 2003). However, when comparing home range between individuals, the use of h derived from lscv will make the size of each individuals range dependent not only on size, but also on how the fixes are distributed within the range. Kenward (2003) suggests overcoming this by determining the lscv multiplier of href for each individual and then running the kernel analysis for each individual using the mean multiplier of href. This method was adopted for kernel home range analysis here.

Another issue in kernel home range analysis is the choice of adaptive or fixed smoothing. Adaptive smoothing changes the value of h across the distribution of fixes, while fixed smoothing uses the same value of h. Two studies have found that adaptive smoothing is likely to overestimate home range area (Worton 1995; Seaman and Powell 1996), and therefore fixed smoothing is used here.

132 The final consideration in kernel home range analysis is the number of fixes taken on an individual necessary for the analysis to adequately describe the home range. Seaman et al. (1999) analysed the effect of sample size, concluding that when using lscv to determine smoothing, a minimum of 30 fixes on an individual were required (but preferably greater than 50). In order to increase the sample size (of individuals) here, lscv was determined for those individuals with greater than 30 fixes to find the mean multiplier of href, but some individuals with less than 30 fixes were included in the home range analyses (5 M. brevirostris and 3 M. lunatus). Individuals with greater than sixteen fixes were included in analyses.

5.2.4.3 Movement The distance between two consecutive fixes on an individual was determined from the AMG for each fix and Pythagoras’ theorem. Individuals with more than one fix on a day were used to examine movements. The time between fixes was split into three time classes; <0.5 hours, 0.5-1 hours, >1 hour. Initial examination of the data in five time classes (<0.5, 0.5-1, 1-2, 2-4, 4+ hours) suggested little effect of time class on movement above 1 hour. Two factor ANOVAs were carried out within a season on the effects of time class and taxa on distance moved. There was a level of repeated measures within each time class caused by having data from the same individual(s) in more than one time class. However, as all individuals were not present in all time classes it was not possible to carry out a repeated measures analysis. Therefore, there is an unknown chance of making a type I error for the effect of time class analysis (i.e. the quoted α may be incorrect). Data were ln transformed to meet the assumption of normality for ANOVA (Zar 1984), with all data being normal after transformation. The Shapiro-Wilk W test was used to test for normality using JMP IN software (SAS Institute Inc. 1997). ANOVA, t-tests and Tukey tests were also carried out using JMP IN. For Tukey tests, a statistical effect was accepted at α = 0.05. All movement data are presented as the antilog of the ln mean ± standard error.

5.3 Results

5.3.1 Summary In all, 76 M. brevirostris, 81 M. lunatus, 1 M. gularis and 5 P. novaehollandiae were fitted with colour-bands during this project (Appendix 1). Data on a further three

133 colour-banded M. gularis were also included (Appendix 1). Radio-tags were fitted on 22 occasions to M. brevirostris, 23 to M. lunatus, one to M. gularis and six to P. novaehollandiae (Appendix 2). Table 5.5 summarises radio-tag data from each site, including the sex and mean number of fixes and days for birds at each site. A number of individuals were resighted over two years after the radio-tracking period, suggesting little effect of the radio-tracking on survival of the tagged individuals (although see next paragraphs). Table 5.6 gives the known mean survival times post radio-tracking for each species. Four birds were radio-tagged twice during the length of the study (Table 5.7) and for each of these individuals, if enough fixes were obtained, each tracking period was treated as a new individual in the analysis.

Of the four individuals recaptured to remove transmitters, a M. brevirostris gained 0.52 g in four weeks, a M. lunatus gained 0.53 g in two weeks and a P. novaehollandiae lost 1.5 g in three weeks. Each of these individuals was weighed after removing the transmitter. One other individual could not be weighed on removing the transmitter due to a flat battery on the scales. One further individual (M. brevirostris RMWB) was re- caught after four days and on finding it had lost 2.5 g in those four days the transmitter was removed. This bird was not resighted.

One juvenile female M. lunatus (RMYR) was radio-tagged during February 2002 at Scott Conservation Park and was apparently taken by a Kookaburra. The bird was caught at 14:00 on the 15th February and fitted with a radio-tag. The bird was sighted about four hours after release over 100 metres from the release site and appeared to be unencumbered by the transmitter. The next day no signal was obtained from the area of last sighting, but while tracking other birds the appropriate frequency was occasionally checked. Eventually, static was detected and could only be heard on the frequency of the radio-tag attached to M. lunatus RMYR. While attempting to track the static, I eventually realised the static disappeared when a Kookaburra moved. More careful following of the Kookaburra confirmed that the Kookaburra was almost certainly carrying the radio-tag and had presumably consumed it along with M. lunatus RMYR. The signal could only be detected for about 50 m from the Kookaburra, so it was not without luck that the fate of M. lunatus RMYR was determined. The Kookaburra did not appear to be inconvenienced. Melithreptus lunatus RMRY was not resighted at any later time and fixes on its radio-tag were not included in any analyses.

134 Table 5.5: Summary of radio-tracking data by site and season

Individuals are the total number of individuals to which radio-tags were attached at that site in each season. Records are the mean records obtained on each of those individuals. Days are the mean number of days each of those individuals were radio-tracked. Species Site Season Individuals Records Days M. brevirostris Kaiser Breeding 2 37 12 Scott Breeding 6 57 15 Newland Non-breeding 5 51 10 Scott Non-breeding 1 23 8 M. lunatus Kaiser Breeding 4 47 12 Scott Breeding 4 77 22 Newland Non-breeding 1 18 25 Scott Non-breeding 2 48 11 Scott Creek Non-breeding 4 49 15 M. gularis Scott Breeding 1 116 27 P. novaehollandiae Scott Non-breeding 5 73 19

Table 5.6: Known mean and maximum survival post radio-tracking

Of the individuals radio-tagged, the number resighted, the mean maximum known survival post radio- tracking of all resighted individuals and the maximum known survival post radio-tracking for any individual. Individuals Of those resighted Species not resighted resighted Mean Days Maximum Days M. brevirostris 4 18 260 682 M. gularis ♀ 0 1 2 2 M. lunatus ♀ 2 6 243 643 M. lunatus ♂ 2 12 203 880 P. novaehollandiae ♀ 1 0 P. novaehollandiae ♂ 2 3 31 57

Table 5.7: Details of the four individuals that were radio-tagged during more than one tracking period

Species Metal Colours Site Initial Second M. brevirostris 025-77711 RMGR Scott July/2001 Aug/2002 M. brevirostris 025-79985 RMRR Scott Nov/2002 April/2003 M. lunatus ♂ 026-01631 RMBN Scott Feb/2002 Nov/2002 P. novaehollandiae ♂ 036-29133 YMYO Scott April/2003 May/2003

135 5.3.2 Description of areas used by Melithreptus

5.3.2.1 Scott Area Figure 5.3 illustrates the general topography of the Scott area, including all fixes taken on Melithreptus. The northern part of the Scott area, in total about 90 hectares, consisted mainly of an open E. leucoxylon and/or E. fasciculosa woodland between two drainage lines with restricted patches of E. viminalis mostly on the drainage lines. The understorey was open, consisting mainly of Acacia pycnantha and Bursaria spinosa with grasses, sedges and occasional patches of Callistemon rugulosus and dense Acacia paradoxa. Most radio-tagged individuals were caught at a dam in the centre of this area but a few were caught along the drainage lines in areas of low Callistemon or E. viminalis. Radio-tagged birds moved mostly within the E. leucoxylon and/or E. fasciculosa within the park and on neighbouring properties. On several occasions M. lunatus moved out of their home range area to feed in E. viminalis along drainage lines in cropping land to the west of the park, visible in the northern half of Figure 5.3 to the west of Deep Creek Rd. One M. lunatus moved about two and a half kilometres south to the Currency Creek area (see below).

Just south and to the northwest of the E. leucoxylon and/or E. fasciculosa woodland, the majority of the park (~150 hectares) and some adjacent properties consisted of E. baxteri and/or E. cosmophylla and/or E. fasciculosa open woodland on low hills with a heath understorey consisting mainly of Xanthorrhoea semiplana and epacrid shrubs. There were a few patches of dense Banksia ornata. This area was rarely used by radio- tagged birds. Occasionally radio-tagged M. lunatus and M. brevirostris moved into the area in small flocks, often of mixed species composition, where they were usually found foraging, often probing under bark. These were clearly birds leaving a relatively small area in which they were recorded frequently and moving into an area in which they were recorded infrequently over a relatively large area. Many radio-tagged birds also roosted in these areas, with all M. brevirostris flocks and two pairs of M. lunatus roosting in areas dominated by E. baxteri (sometimes a long way into the E. baxteri from the E. leucoxylon and/or E. fasciculosa woodland, e.g. 500m).

South again of this area, outside the park, was another drainage line with similar vegetation to the one on the north edge of the park (about another 17 hectares). Two

136 radio-tagged birds were caught here, the M. gularis and a M. lunatus. Melithreptus brevirostris were also recorded frequently in the area during the radio-tracking period. Towards the higher (western) end of this drainage line there was an area of mixed E. odorata and E. leucoxylon (about seven hectares) used by M. brevirostris and a radio- tagged M. gularis.

South of the second drainage line, there were about 100 hectares consisting of open woodland, predominantly E. fasciculosa, paddocks with only a few scattered trees (mainly E. camaldulensis), some revegetated areas (most between fifteen and twenty years old, and not all containing locally native eucalypts) and Currency Creek, which occurred in land cleared for agriculture but with E. camaldulensis woodland immediately surrounding the creek. There were also some small areas of E. viminalis near to the creek. These whole area was surrounded by predominantly agricultural land. Currency Creek lay about two and a half kilometres south of the northern edge of the Scott area (the main study area). Two radio-tagged birds used this area, the M. gularis and a male M. lunatus caught in the study site at the northern edge of Scott. The male M. lunatus visited E. viminalis near Currency Creek which was the only E. viminalis this bird was seen to visit – its home range within the northern part of Scott did not contain any E. viminalis. Both birds also moved along the narrow corridor of woodland along Currency Creek.

137 Figure 5.3: Topographic map of the Scott area with all Melithreptus fixes

5.3.2.2 Kaiser Stuhl Area Figure 5.4 illustrates the general topography of the Kaiser Stuhl area, including all fixes taken on Melithreptus. Most work occurred near the northeast boundary of the

138 Conservation Park and surrounding properties. This area was about 30 hectares and consisted of previously cleared grassland with areas of E. viminalis, E. camaldulensis and small patches of E. leucoxylon. All radio-tagged birds confined most of their movement to this area. Birds were caught near flowering E. leucoxylon, in a grove of A. pycnantha or near E. viminalis. Just west of this area, most of the park consisted of E. baxteri and/or E. obliqua woodland. Again, radio-tagged M. brevirostris and M. lunatus were occasionally found in small flocks, often of mixed species composition, in the E. baxteri and/or E. obliqua woodland and again the birds left a relatively small area in which they were recorded frequently and moved over a large area in which they were recorded infrequently.

Melithreptus lunatus were recorded roosting in E. obliqua and A. pycnantha, while M. brevirostris were recorded roosting in E. obliqua. Roost sites were not far from the areas in which birds spent most of their time.

Figure 5.4: Topographic map of the Kaiser Stuhl area with all Melithreptus fixes

5.3.2.3 Scott Creek Area Figure 5.5 illustrates the general topography of the Scott Creek area, including all fixes taken on Melithreptus. Work in this park occurred at the bottom of the ‘Greenhood’

139 track, towards the southern and western part of the park. This was an area of steep hills, with the study site centred on a small, broader, flat valley in an area of E. viminalis ± E. leucoxylon woodland. Just downstream (east) was E. leucoxylon ± E. viminalis woodland. On all surrounding slopes and hilltops was E. obliqua woodland. Occasional areas of stunted E. cosmophylla and E. fasciculosa also occurred. All radio-tagged birds were caught at a soak surrounded by Typha and all Melithreptus roosted in areas of E. obliqua, sometimes a considerable distance from their core areas of activity. For example, the two most northerly fixes in Figure 5.5 were the roost sites of two different M. lunatus.

Again, radio-tagged birds were occasionally found in small flocks in the E. obliqua woodland, always of mixed species composition, and again the birds left relatively small area(s) in which they were recorded frequently and moved over a large area in which they were recorded infrequently. Melithreptus present in these flocks were generally probing under bark in E. obliqua. In the month after radio-tracking, in the vicinity of the site, and using the methods of Paton (1980), the standing crop of honeydew and insects under peeling bark on the branches of E. obliqua were measured. Standing crop, measured between early and mid-morning, was 308 J honeydew per metre of peeling E. obliqua bark (6.7 metres of peeling bark on 14.1 metres of branch from 29 branches, accessible with a 2 metre ladder, in 22 trees were measured). This does not include honeydew which occurred as a thin film over a branch but with no appreciable volume (potentially areas already foraged). Under the same bark there were about 187 J of insects per metre, or 108 J per metre excluding small black ants.

140 Figure 5.5: Topographic map of the Scott Creek area with all Melithreptus fixes

5.3.2.4 Newland Head Area Figure 5.6 illustrates the general topography of the Newland Head area, including all fixes taken on Melithreptus. The work at Newland Head took place in the very northern edge of the Conservation Park and adjacent properties. There was a mix of vegetation including areas of E. diversifolia ± E. incrassata mallee, E. baxteri open woodland, small patches of E. fasciculosa woodland and some areas of dense Banksia ornata. There were also some areas of previously cleared land that contain E. cosmophylla thickets over pasture. All radio-tagged birds were caught in nets by either a dam or trough, or near flowering E. baxteri and used all habitats present at the site, except for the dense Banksia ornata in which no records of Melithreptus were taken. During the tracking period, this Banksia was flowering and was densely populated by P. novaehollandiae. This area can be seen as a gap in records towards the very north of the park. Melithreptus lunatus were recorded roosting in E. viminalis along the drainage line to the north of the park (see next paragraph), while M. brevirostris were recorded roosting in E. diversifolia.

Just over one kilometre north of the main study area was a drainage line with E. viminalis, E. fasciculosa, E. leucoxylon and E. camaldulensis, that most radio-tagged individuals visited at some stage. To get to this drainage line they followed a thin corridor of vegetation (about 10 m wide E. baxteri with no understorey) and crossed an area of scattered E. fasciculosa and E. leucoxylon (in which they were recorded feeding). A corridor of Pinus sp. nearby was not recorded being used by Melithreptus.

141 One M. brevirostris flock also moved on several occasions to an isolated block of scrub (of similar vegetation type) to the east of Newland Head Conservation Park. In doing so the birds moved either along the corridor of vegetation visible on the east side of the Conservation Park or by moving through a completely open pasture via small shrubs or very isolated trees (two isolated trees are marked by labelled points in Figure 5.6). The entire flock (11 birds on both occasions) landed in the isolated tree or shrub before moving on (shrub canopies were in the order of 1 m3).

I have no good explanation for the apparent (nearly north-south) line marking the western edge of the fixes, leaving the western edge of the park empty of fixes. The vegetation did not appreciably change on either side of the line and it falls across the direction of contours in the area. The best explanation is that perhaps another M. brevirostris flock occurred in this area. No evidence of one was found but no concerted search effort was made. There was no interaction between focal flocks and the flock in the area if there was one, despite a couple of interactions being recorded between the two flocks representing most of the fixes and other flocks to the south and a suspected flock to the east. The suspected flock interacted with a focal flock in the isolated patch of scrub on the eastern edge of Figure 5.6.

142 Figure 5.6: Topographic map of the Newland Head area with all Melithreptus fixes

North is up. Each grid square on the map is 1 km2. The dot, dash line is the boundary of the Conservation Park. Numbers on contours represent height in metres. Large black squares are fixes on Melithreptus. The two labelled points are isolated trees used by a M. brevirostris flock in crossing open pasture areas (the numbers refer to waypoint identifiers).

5.3.3 Home range results

5.3.3.1 Small Melithreptus guild

5.3.3.1.1 Overall MCP (100%) The results for overall MCP of the small Melithreptus species/sex guild are summarised in Figure 5.7. During the breeding season male M. lunatus had the smallest overall MCP

143 (5.08 ha), similar in size to female M. lunatus (8.56 ha) and half M. brevirostris (11.91 ha). During the non-breeding season M. brevirostris had the largest MCP (48.57 ha) being over five times that of female M. lunatus (8.42 ha) and over three times that of male M. lunatus (14.89 ha). Statistically, there was no interaction and no effect of season, but an effect of species/sex (Figure 5.7) on overall MCP. Melithreptus brevirostris had larger overall MCP home ranges than M. lunatus.

Figure 5.7: Mean overall MCP (ha) (± s.e.) in breeding and non-breeding seasons for the small Melithreptus guild

Individuals, mean records per individual ± standard error are as follows: breeding season; M. brevirostris 11, 40.55±9.59; M. lunatus ♀ 3, 50.67±11.05; M. lunatus ♂ 6, 58.83±15.37; and non-breeding season; M. brevirostris 10, 32.1±8.16; M. lunatus ♀ 4, 24.75±10.23;. Melithreptus lunatus ♂ 7, 36±9.03. There was

no interaction between species/sex and season (F2,35=0.8811; P=0.4233), a weak effect of season

(F1,35=3.7759; P=0.0601) but an effect of species/sex (F2,35=3.607; P=0.0376) with M. brevirostris having larger overall MCP than M. lunatus in which both sexes had similar sized overall MCP.

60 a)

(h 50 M. brevirostris 40 M. lunatus ♀ M. lunatus ♂ ll 100% MCP 30 Overa 20

0 Breeding Non-breeding Season

5.3.3.1.2 Daily MCP (100%) The daily MCPs for the small Melithreptus guild are summarised in Figure 5.8. During the breeding season, M. brevirostris had the largest daily MCP (2.10 ha) at about three times the size of female M. lunatus (0.66 ha) and about four times male M. lunatus (0.46 ha). Melithreptus brevirostris also had the largest daily MCP during the non- breeding season (12.11 ha) at about three and a half times the size of female M. lunatus

144 (3.24 ha) and eight and a half times male M. lunatus (1.38 ha). The daily MCPs of male M. lunatus were smaller than female M. lunatus in the non-breeding season, but both were similar in the breeding season. Statistically, there was no interaction but an effect of species/sex and season on daily MCP (Figure 5.8). Each species/sex had a larger daily MCP in the non-breeding season than in the breeding season. The Tukey test found M. brevirostris had larger daily MCP than male M. lunatus, but similar to female M. lunatus. Female M. lunatus were also similar to male M. lunatus. Thus, there is a continuum of daily MCP from M. brevirostris through female M. lunatus to male M. lunatus, with the only statistical difference being that M. brevirostris is larger than male M. lunatus.

The daily MCP as a percent of the overall MCP is given in Table 5.8. Melithreptus brevirostris cover a larger percent of their overall MCP each day than M. lunatus in the breeding season, but in the non-breeding season, a large increase in the percent covered by female M. lunatus puts them above M. brevirostris, while male M. lunatus barely increase their coverage between seasons.

Table 5.8: Daily MCP as a percent of overall MCP

Daily MCP as a percent of overall MCP during the breeding and non-breeding seasons. Species/sex Breeding Non-breeding Non-breeding/Breeding M. brevirostris 17.7 24.9 1.4 M. lunatus ♀ 7.7 38.5 5.0 M. lunatus ♂ 9.0 9.3 1.0

145 Figure 5.8: Mean daily MCP (ha) (± s.e.) in breeding and non-breeding season for the small Melithreptus guild

Individuals, mean days per individual ± standard error are as follows: breeding season; M. brevirostris 10, 5.4±0.99; M. lunatus ♀ 4, 4.75±1.31; M. lunatus ♂ 6, 6.83±2.09; and non-breeding season; M. brevirostris 11, 4.09±1.04; M. lunatus ♀ 3, 4.00±1.73;. Melithreptus lunatus ♂ 7, 3.86±1.12. There was

no interaction between species/sex and season (F2,35=0.2598; P=0.7727) but an effect of season

(F1,35=11.3164; P=0.0019) and species/sex (F2,35=8.9717; P=0.0007) on daily MCP.

16 )

a 14

ea (h 12 ar

P M. brevirostris C 10 M. lunatus ♀ M. lunatus ♂ 8

6 Daily 100% M

0 Breeding Non-breeding Season

5.3.3.1.3 Kernel Kernel home range (KH) results are summarised in Figure 5.9. At the 10% UD during the breeding season M. brevirostris and female M. lunatus had very similar KH (0.016 ha) at just over four times the KH of male M. lunatus (0.004 ha). During the non- breeding season, male M. lunatus again had the smallest KH (0.031 ha) at just under half M. brevirostris and female M. lunatus which were again similar (~0.071 ha). Statistically, there were no effects of species/sex or interaction of species/sex and season, but there was an effect of season on KH. Each species/sex had a larger 10% KH during the non-breeding season than the breeding season.

At 50% UD, during the breeding season M. brevirostris and female M. lunatus again had similar KH (0.190 ha) at about seven times that of male M. lunatus (0.03 ha). During the non-breeding season, M. brevirostris had the largest KH (1.29 ha), followed

146 by female M. lunatus (0.78 ha) and then male M. lunatus (0.23 ha). Statistically, there were effects of species/sex and season, but no interaction on 50% UD. Each species/sex had a larger 50% UD during the non-breeding season than the breeding season. The Tukey test found M. brevirostris had larger 50% UD than male M. lunatus, but similar to female M. lunatus. Female M. lunatus were also similar to male M. lunatus. Thus, there was a continuum of 50% UD from M. brevirostris through female M. lunatus to male M. lunatus, with the only statistical difference being that M. brevirostris 50% UD were larger than male M. lunatus.

During the breeding season M. brevirostris had the largest 90% UD KH (1.7 ha), then female M. lunatus (1.2 ha) and then male M. lunatus (0.2 ha). During the non-breeding season, M. brevirostris again had the largest KH (5.2 ha) followed again by female M. lunatus (2.4 ha) and then by male M. lunatus (0.6 ha). Statistically, there were effects of species/sex and season, but no interaction on 90% UD. Again, each species/sex had a larger 90% UD during the non-breeding season than the breeding season and the Tukey test found the same result for species/sex as the 50% UD.

As a percentage of the overall MCP, KH at the 10, 50 and 90% UD shows some interesting trends (Table 5.9). In the breeding season M. brevirostris and female M. lunatus were similar and used a substantially higher percent of their overall MCP than male M. lunatus. However, in the non-breeding season, at each KH UD, female M. lunatus increased the percentage of overall MCP used to a much higher degree than either M. brevirostris or male M. lunatus.

Table 5.9: Kernel home range at each utilisation distribution expressed as a percent of overall MCP during the breeding and non-breeding seasons

% of MCP UD Species/sex Breeding Non-breeding Non-breeding/Breeding 10% M. brevirostris 0.1 0.2 1.2 M. lunatus ♀ 0.2 0.8 4.2 M. lunatus ♂ 0.1 0.2 2.6 50% M. brevirostris 1.6 2.7 1.7 M. lunatus ♀ 2.1 9.3 4.4 M. lunatus ♂ 0.5 1.5 2.9 90% M. brevirostris 14.0 33.6 2.4 M. lunatus ♀ 13.6 58.0 4.3 M. lunatus ♂ 3.6 12.9 3.6

147 Figure 5.9: Mean kernel home range (ha) (± s.e.) for the small Melithreptus guild in a) the breeding season; and b) the non-breeding season.

Home range (ha) is on a log scale. Individuals, mean records per individual ± standard error are as follows. Breeding M. brevirostris 8, 51.6±10.3; M. lunatus ♀ 3, 50.7±9.6; M. lunatus ♂ 5, 67.6±14.3. Non-breeding M. brevirostris 6, 46.3±9.2; M. lunatus ♀ 2, 41.0±7.7; M. lunatus ♂ 5, 45.2±9.1. At the

10% UD there was no interaction between species/sex and season (F2,23=0.1920; P=0.8266) or effect of

species/sex (F2,23=2.4271; P=0.1106) but there was a weak effect of season (F1,23=9.3303; P=0.0056). Each species/sex had a larger non-breeding 10% UD KH than breeding. At the 50% UD there was no

interaction between species/sex and season (F2,23=0.36713; P=0.8995), an effect of species/sex

(F2,23=5.9670; P=0.0082) and an effect of season (F1,23=11.4721; P=0.0025). Each species/sex had a larger non-breeding 50% UD KH than breeding. The Tukey test found M. brevirostris and female M. lunatus had similar sized 50% UD KH and female M. lunatus and male M. lunatus had similar sized 50% UD KH. Melithreptus brevirostris have larger 50% UD KH than male M. lunatus. At the 90% UD there

was no interaction between species/sex and season (F2,23=0.2173; P=0.8063), an effect of species/sex

(F2,23=7.7003; P=0.0028) and an effect of season (F1,23=13.5358; P=0.0012). Each species/sex had larger non-breeding 90% UD KH than breeding. The Tukey test found M. brevirostris and female M. lunatus had similar sized 90% UD KH and female M. lunatus and male M. lunatus had similar sized 90% UD KH. Melithreptus brevirostris had larger 90% UD KH than male M. lunatus.

148 Figure 5.9 a) Breeding season

1 a) h e ( g 0.1 M. brevirostris ran e M. lunatus ♀ m o M. lunatus ♂ h l e 0.01 Kern

0.001

0.0001 0 102030405060708090100 Utilisation Distribution

Figure 5.9 b) Non-breeding season

100

10 a) h e ( g 1 M. brevirostris ran e M. lunatus ♀ m o M. lunatus ♂ h l e 0.1 Kern

0.01

0.001 0 102030405060708090100 Utilisation Distribution

149 5.3.3.2 Melithreptus gularis Each of the home range analyses are displayed for the single M. gularis in Figure 5.10. The M. gularis had an overall MCP of about 140 ha (> 10 times M. brevirostris) and average daily MCP of about 15 ha (> 7 times M. brevirostris). It is clear from Figure 5.11 that the M. gularis tracked had a much larger kernel home range at all utilisation distributions than either M. brevirostris or M. lunatus. KH at 10% utilisation distribution was 0.21 hectares (12 times female M. lunatus), at 50% it was 4.0 hectares (~4 times M. brevirostris) and at 90% it was 22.79 hectares (~14 times M. brevirostris).

The M. gularis used about 10% of its overall MCP each day, and the 10, 50 and 90% UD KH were 0.15%, 2.85% and 16.28% of its overall MCP, respectively.

150 Figure 5.10: Home range analyses carried out on the M. gularis

Each yellow dot represents one fix on M. gularis WMRR. The red polygon is the overall MCP (100%). The orange polygons represent the daily MCP (100%) for each day with greater than three records and the green polygons are the KH at various UD. The yellow bar at the bottom left represents 1 km. The south end of Scott Conservation Park is visible in the top right of the picture.

S# S#S#S# S#S# S#S# S# S# S# S#S## S# S# S# S# S# S# S# S# S#S# S# S# S#S# S#S# S# S# S# S# # # S# S# # S# S# S S# S S# S#S# # S# S# S# S#S# S S## # S# S S S#S#S# S#S# S# S# S #S# S#S S# S#S# S# S# S#

S# S# S#

S# S#

S# S# S#

S# S#

100% MCP - All records Scott CP Creeks 1km Scale Bar Roads 100% Daily MCPs S# Individual Fixes Kernel Contours 10 50 90

151 Figure 5.11. Mean breeding season kernel home range (ha) (± s.e.) for the single M. gularis, compared with M. brevirostris and M. lunatus

Home range (ha) is on a log scale. Individuals, mean records per individual ± standard error are as follows; M. brevirostris 8, 51.6±10.3; M. lunatus 8, 61.3±9.9; M. gularis 1, 116.

100

10 a) h e (

g 1 M. brevirostris ran e M. lunatus m o M. gularis h l

e 0.1 Kern

0.01

0.001 0 102030405060708090100 Utilisation Distribution

5.3.3.3 Comparison of Melithreptus home range statistics with P. novaehollandiae in the non-breeding season Figure 5.12 summarises the various home range statistics for P. novaehollandiae and compares them with those obtained during the non-breeding seasons for Melithreptus. The Melithreptus had an overall MCP over ten times larger (23.45 ha) and daily MCP over ten times larger (4.86 ha) than P. novaehollandiae (2.21 and 0.47 ha respectively). All differences were supported statistically (Figure 5.12). Results were similar for KH, with Melithreptus KH many times larger (10% UD 0.052 ha, 50% UD 0.614 ha and 90% UD 5.9 ha) than P. novaehollandiae (0.002 ha, 0.025 ha and 0.25 ha), again supported statistically (Figure 5.12).

Phylidonyris novaehollandiae used a much smaller area than Melithreptus overall, but they also used smaller proportions of that area (Table 5.10). The KH as a percent of overall MCP area at the 10, 50 and 90 UD show that Melithreptus used a greater percentage of their overall MCP than P. novaehollandiae. Melithreptus used a percentage of the overall MCP area (10% UD: 0.22%; 50% UD: 2.62%; and 90% UD: 25.36%) about twice as high as P. novaehollandiae (0.09%; 1.13%; and 11.31%). On a

152 daily basis, Melithreptus and P. novaehollandiae both covered about 20% of their overall MCP.

Table 5.10: Melithreptus and P. novaehollandiae home range statistics as a percent of overall MCP

Each home range type is expressed as a percent of overall MCP during the non-breeding season. Home range type Melithreptus P. novaehollandiae Daily MCP 20.73 21.51 Kernel HR 10% UD 0.22 0.09 Kernel HR 50% UD 2.62 1.13 Kernel HR 90% UD 25.36 11.31

153 Figure 5.12: Mean home range (ha) (± s.e.) for Melithreptus and P. novaehollandiae; a) overall MCP; b) daily MCP and c) kernel.

Melithreptus data includes all individuals radio-tagged in the non-breeding season. a) Overall MCP. Individuals, mean records per individual ± standard error are as follows: Melithreptus

21, 32±5.1; and P. novaehollandiae 6, 61.7±16.6 (t25=3.153, P=0.0042).

40 a)

(h 35

ea 30

P Ar 25 C

M 20 %

0 15 0 1 l 10 5

Overal 0 Melithreptus P. novahollandiae Species b) Daily MCP. Individuals, mean days per individual ± standard error are as follows: Melithreptus 21,

4.0±0.7; and P. novaehollandiae 5, 8.8±1.6 (t24=2.895, P=0.0079).

8 7

(ha) 6 P 5 MC 4 0% 3 y 10

il 2

Da 1 0 Melithreptus P. novahollandiae Species

c) Kernel. Individuals, mean records per individual ± standard error are as follows: Melithreptus 13,

45.1±5.7; and P. novaehollandiae 5, 72.8±15.1 (10%: t16=4.04, P=0.0009; 50%: t16=3.644, P=0.0022;

90%: t16=3.632, P=0.0022).

100

a) 10 e (h

ng 1 a r Melithreptus 0.1 me P. novaehollandiae

ho 0.01

0.001 Kernel 0.0001 050100 Utilisation Distribution

154 5.3.4 Movement results

5.3.4.1 Small Melithreptus guild During the breeding season M. brevirostris and M. lunatus all moved short distances in less than half an hour (Figure 5.13, M. brevirostris: 35 m; M. lunatus ♀: 37m; and M. lunatus ♂24 m), increasing steadily through each time class (0.5-1.0 hr: 82 m; 63 m; and 49 m. >1.0 hr: 125 m; 90 m; and 47 m), except for male M. lunatus which did not increase the distance moved above one hour. During the non-breeding season, each species/sex appeared to move further with each increasing time class (<0.5 hr: M. brevirostris 87 m; M. lunatus ♀ 55 m, and M. lunatus ♂ 43 m; 0.5-1.0 hr: 239 m, 133 m and 102 m; >1.0 hr: 351 m, 162 m and 159 m), particularly M. brevirostris. However, statistically the effect of time class was the same in both seasons; there was no difference in distance moved above half an hour and the distance moved in less than half an hour was statistically less than above half an hour. While M. lunatus sexes appeared to move similar distances within each time class and less than M. brevirostris, statistically there was a continuum of distance moved from M. brevirostris through female M. lunatus to male M. lunatus, with only M. brevirostris and male M. lunatus statistically different.

155 Figure 5.13: Mean distance moved (metres) (± s.e.) between fixes by the small Melithreptus guild

Individuals, mean records ± standard error are as follows; Breeding season; M. brevirostris 13, 33.2±8.6; M. lunatus ♀ 7, 23.7±10.1 and M. lunatus ♂ 8, 43.9±13.8; and non-breeding season; M. brevirostris 13, 24.8±6.9; M. lunatus ♀ 5, 18.6±7.9 and M. lunatus ♂ 9, 26.2±8.2. In the breeding season there was no interaction between species/sex and season (F4,80=0.2201; P=0.9265) or effect of species/sex (F2,80=2.038;

P=0.137) but there was an effect of time class (F2,80=4.4433; P=0.0148) on distance moved. For time class, the Tukey test found there was no difference in the distances moved between 0.5-1.0 and >1.0 hours. The distances moved in these time classes were greater than the distances moved <0.5 hour. In the non-breeding season there was no interaction between time classes and species/sex on distance moved

(F4,74=0.0723; P=0.9903), but an effect of time class (F2,74=13.5797; P<0.0001) and species (F2,74=6.9933; P=0.0017) on distance moved. For time class, the Tukey test found the same result as for the breeding season, and for species effect, again, there was a continuum from M. brevirostris through female M. lunatus to male M. lunatus, with the only statistical difference being that M. brevirostris moved further than male M. lunatus.

450

400

350 ) 300 etres

(m 250 M. brevirostris M. lunatus ♀ 200 M. lunatus ♂

stance moved 150 i D 100

0 <0.5 0.5-1.0 >1.0 <0.5 0.5-1.0 >1.0

Breeding Non-breeding Time class (hours) and Season

5.3.4.2 Melithreptus gularis Data from two individuals were available for the breeding season with four records on one individual and 117 on the other. Melithreptus gularis moved nearly six times as far as the smaller Melithreptus in less than half an hour and over three times as far as the smaller Melithreptus in over half an hour (<0.5 hr: 206 metres, 0.5-1.0 hr: 210 metres, >1.0 hr: 317 metres).

156 5.3.4.3 Comparison of distance moved between Melithreptus and P. novaehollandiae in the non-breeding season From Figure 5.14 it appears that Melithreptus moved further in each successive greater time class (<0.5 hr: 66 m; 0.5-1.0 hr: 165 m; >1.0 hr: 245m), while P. novaehollandiae moved a similar distance within each time class (<0.5 hr: 51 m; 0.5-1.0 hr: 62 m; >1.0 hr: 74 m). However, this interaction was not supported statistically. Melithreptus moved further between fixes than P. novaehollandiae and both taxa moved further at time scales above half an hour than between fixes taken less than half an hour apart.

Figure 5.14: Mean distance (metres) (± s.e.) moved between fixes in the non-breeding season by Melithreptus and P. novaehollandiae

Individuals, mean records per individual ± standard error are as follows; Melithreptus: 28, 23±5; P. novaehollandiae: 5, 82±28. There was no interaction between time classes and taxa on distance moved

(F2,92=1.3653; P=0.2604), but an effect of time class (F2,92=4.1401; P=0.0190) and taxa (F1,92=10.6607; P=0.0015) on distance moved. For time class, the Tukey test again found there was no difference in the distances moved between 0.5-1.0 and >1.0 hours. The distances moved in these time classes were greater than the distances moved <0.5 hours.

350

300

250 ) res

et 200

m Melithreptus (

ce P. novaehollandiae an

t 150 Dis

100

0 <0.5 0.5-1.0 >1.0 Time Class

5.3.5 Residency of individuals: Scott area data While the colour-band re-sighting data were collected only opportunistically, they provide the best information on long-term (several years) residency of individuals. Appendix 3 provides colour-band re-sighting data for the Scott area by year and month.

157 A large proportion of the M. brevirostris population appeared to be resident throughout the year (Table 5.11), with 61% of adult M. brevirostris and 77% of young M. brevirostris seen in both seasons. The individuals seen in both seasons were seen over at least a year, while those birds seen in only one season were only seen for very short periods of time (Table 5.12). This provides good evidence that the M. brevirostris population in the Scott area was resident throughout the year and that birds that were not re-sighted in both seasons were not migratory, but were transient, emigrated or died. Overall, of the 41 individuals colour-banded, 83% were re-sighted at some point, with the mean interval between re-sights being one year. Nineteen individuals were resighted over periods greater than one year and six individuals over periods greater than two years.

A greater proportion of the male M. lunatus population appeared to be resident than the female M. lunatus population, with 71% of young and 58% of adult male M. lunatus seen for intervals well over a year and in both breeding and non-breeding seasons, compared with 10% and 13% for young and adult female M. lunatus respectively. This provides good evidence that the male M. lunatus population in the Scott area was generally resident throughout the year and that birds that were not re-sighted in both seasons were not migratory, but were transient, emigrated or died. The opposite is true for both young and adult female M. lunatus. Most female M. lunatus were not re-sighted (young birds 60% and adult birds 50%). Only 10% of young and 13% of adult female M. lunatus were sighted in both seasons. Only two female M. lunatus were sighted over intervals of longer than a year, and only one of those was sighted in both seasons. However, one of these individuals was sighted in four breeding seasons and the other during two breeding seasons (Appendix 3). This provides evidence that some female M. lunatus in the Scott area return to their breeding areas during the breeding season but leave them during the non-breeding season.

158 Table 5.11: Percent of Melithreptus individuals re-sighted in the Scott area in different ‘seasons’

Percent and number of individuals (in brackets) of individuals resighted. Young birds include individuals first caught as juveniles, immatures, sub-adults and 1st year adult birds. Adult birds refers to individuals first caught as adult birds (>1 year of age). Each colour-banded individual contributes to only one column, except overall where all individuals contribute. For both young and adult birds, more M. brevirostris and male M. lunatus were resighted in both seasons than in one season only or never. More female M. lunatus were never re-sighted than other categories. Young birds Adult birds Overall Species/sex Both Breeding Non-breeding Never Both Breeding Non-breeding Never M. brevirostris 76.9 (10) 7.7 (1) 15.4 (2) 0 (0) 60.7 (17) 10.7 (3) 3.6 (1) 25 (7) 82.9 (41) M. lunatus ♀ 10 (1) 20 (2) 10 (1) 60 (6) 12.5 (1) 12.5 (1) 25 (2) 50 (4) 44.4 (18) M. lunatus ♂ 71.4 (5) 0 (0) 28.6 (2) 0 (0) 57.1 (4) 14.3 (1) 28.6 (2) 0 (0) 100 (14)

Table 5.12: Mean interval (years) between first and last sightings of individual colour-banded Melithreptus in the Scott area

Sample size and definitions are the same as Table 5.11 (birds never re-sighted are not included here). Generally, young Melithreptus individuals that were recorded in both seasons were recorded over longer intervals than those seen in only one season. This suggests that the individuals seen in only one season were not migratory, but were transient, dispersed or died. For adult M. brevirostris and male M. lunatus, the individuals recorded in both seasons were recorded over longer intervals than those seen in only one season. This suggests that the individuals seen in only one season were not migratory, but were transient, emigrated or died. Despite more adult female M. lunatus being re-sighted in the non-breeding season, those that were re-sighted in both seasons, or only during the breeding season, were re-sighted over much longer intervals. This suggests that female M. lunatus were more mobile during the non-breeding season than either M. brevirostris or male M. lunatus. Young birds Adult birds Overall Species/sex Both Breeding Non-breeding Both Breeding Non-breeding M. brevirostris 1.21 0.04 0.10 1.64 0.03 0.10 0.99 M. lunatus ♀ 0.96 0.03 0.02 1.79 3.07 0.43 0.38 M. lunatus ♂ 1.60 1.53 2.21 0.08 0.40 1.48

159 5.3.6 Flock size and associations The distribution of flock sizes in which known individuals were recorded is given in Figure 5.15 for the breeding season and Figure 5.16 for the non-breeding season. During the breeding season, most individuals were recorded in flocks of two. Melithreptus brevirostris were also recorded in a wide range of flock sizes with another common flock size of seven, while M. lunatus was rarely recorded in flocks sizes greater than three. During the non-breeding season M. brevirostris was most often recorded in a flock of seven, female M. lunatus were most often recorded alone, and male M. lunatus were most often in pairs. Male M. lunatus were also recorded more often in flocks larger than four than female M. lunatus. The distributions of M. brevirostris flock size in both seasons were distinctly bimodal.

Melithreptus brevirostris was generally recorded in larger groups of conspecifics, which appeared to consist of the same individuals through time. Records of colour-banded birds were used to infer associations between individuals (an example for M. brevirostris RMRR is given in Table 5.13). This information was summarised for each species/sex to give estimates of the relative stability of flock composition between species (Table 5.14). While composition will be underestimated, as only known (colour- banded) birds could be associated, the relative values enable inferences about the social behaviour of Melithreptus to be made. In the Scott area M. brevirostris was associated with more individuals and formed long term associations with more other individuals than either M. lunatus sexes. Male M. lunatus were associated with more other individuals than female M. lunatus although these associations did not last as long (absolute or proportional) as female M. lunatus associations.

160 Figure 5.15: Histogram of Melithreptus flock sizes during the breeding season

Number of individuals, mean records per individual ± standard error are as follows; M. brevirostris: 53, 11±3.1; M. lunatus ♀: 17, 13±5.2; and M. lunatus ♂: 19, 24±7.9.

s 50

40 M. brevirostris ndividual I M. lunatus ♀ of

t 30 M. lunatus ♂ n e c r e 20 P

0 123456789101112 Flock Size

Figure 5.16: Histogram of Melithreptus flock sizes during the non-breeding season

Number of individuals, mean records per individual ± standard error are as follows; M. brevirostris: 51, 10±2.4; M. lunatus ♀: 30, 5±1.9; and M. lunatus ♂: 30, 11±3.4.

50 45 40 s 35 30 M. brevirostris ndividual I 25 M. lunatus ♀ of

t M. lunatus ♂

n 20 e c r

e 15 P 10 5 0 123456789101112 Flock Size

161 Table 5.13: Example of association information for one individual, M. brevirostris RMRR

a): Summary of focal individual: M. brevirostris RMRR. 1st Capture Last sighting Days Years Records Mean flock size 09-Dec-00 12-Jun-03 915 2.51 90 3.4 b) Summary of associations between M. brevirostris RMRR and other known M. brevirostris individuals. The interval of time between the 1st and last associations of the two individuals as a percent of the time during which both individuals were known to be alive is also given (%). Other individual # of associated records 1st association Last association Interval (years) % RMRB 2 09-Dec-00 03-Aug-01 0.65 27.59 RMRG 1 09-Dec-00 09-Dec-00 0 0.00 RMBR 1 03-Aug-01 03-Aug-01 0 0.00 RMRO 1 03-Aug-01 03-Aug-01 0 0.00 RMRW 5 03-Aug-01 12-Jun-03 1.86 82.48 RMRY 6 03-Aug-01 28-May-03 1.82 80.66 RMYN 12 15-Mar-02 28-May-03 1.2 92.42 RMWR 3 24-Jun-02 23-Nov-02 0.42 62.55 RMGY 1 08-Nov-02 08-Nov-02 0 0.00 RMRN 1 23-Nov-02 23-Nov-02 0 0.00

Table 5.14: Details of associations between known individuals for each colour-banded species in the Scott Area n is the number of known (focal) individuals associated with another known individual. Assns is the mean number of associations with another individual over the n focal individuals. Associations are between individuals of the same species regardless of sex. For a focal individual associated on more than one occasion with the same other individual; alive days is the mean number of days the focal individuals were known to be alive, associated days is the mean span of days both individuals were known to be associated, both alive days is the mean number of days that both individuals were known to be alive at the same time and % is the associated days as a percent of the both alive days. > 1 association All associations Known days Species/sex n Assns n Assns Alive Associated Both alive % M. brevirostris 40 6.1 23 2.6 484 202 336 60 M. lunatus ♀ 12 2.3 5 1.2 362 291 311 93 M. lunatus ♂ 13 4.1 8 1.6 719 154 392 39

5.4 Discussion

5.4.1 Comparison with literature The maximum distance between any two points recorded for an individual Melithreptus home range here was smaller (maximum 4.3 km for male M. lunatus RMBN) than the maximum distance obtained for dispersing L. melanops cassidix (Runciman et al. 1995)

162 and of a similar magnitude to that obtained on translocated M. melanocephala (Clarke and Schedvin 1997) (Table 5.1). These other studies did not include home range data in their results.

The small Melithreptus guild in the Mt Lofty Ranges all had larger home ranges than any previously published results for honeyeaters. The closest direct comparison that can be made is with non-breeding L. melanops cassidix which was found to have harmonic mean home range (80% UD) between 0.51 ha (juveniles) and 0.21 ha (non-breeding females of a breeding pair) (Moysey 1997). All Melithreptus had larger kernel home ranges (90% UD, mean 5.3 ha). It is likely that a large amount of the difference in results between this and other home range studies is the use of radio-tags. If radio-tags had not been used in this study, it would still have been possible to find colour-banded individuals 90% of the time in an area less than 1.6 ha in the breeding season or 50% of the time in an area less than 1.3 ha in the non-breeding season. Finding the birds within this area may give an indication that the area they required was considerably smaller than that estimated by radio-tagging, since the chance of detecting colour-banded birds at distant locations is remote.

The only study which used radio-tags to estimate a home range for honeyeaters (Pyke and O'Connor 1993) excluded fixes outside a certain area, making comparisons difficult. They still found a home range for P. novaehollandiae (and P. nigra) (90% MCP, 0.48 ha) larger than that for L. melanops cassidix. Data were collected from February to November, suggesting breeding was likely during some of the time. Again, Melithreptus kernel home range (90% UD) estimates were nearly one and a half times the size of this during the breeding season and over ten times this during the breeding season. Compared to the overall home range results (90% MCP) for P. novaehollandiae and P. nigra, even the daily MCP for the small Melithreptus were larger in the breeding (~1.7×) and non-breeding season (8×).

The kernel home range for P. novaehollandiae (90% UD, 0.250 ha) found here was about half that obtained by Pyke and O’Connor (1993) for the home range of P. novaehollandiae and P. nigra (90% MCP, 0.48 ha). However, KH is likely to be smaller than MCP home range (Carr and Rodgers 1998; Kenward et al. 2003). To compare the studies more closely, the 90% MCP of P. novaehollandiae obtained in the Scott area

163 was determined using Ranges VI as 0.99 +1.49/-1.00 ha (mean ± s.e. based on ln transformed data; arithmetic mean centred method of 90% MCP). This is about two times larger than that calculated by Pyke and O’Connor (1993). The difference between studies may be due to the exclusion of certain fixes by Pyke and O’Connor (1993).

Thus, a comparison with literature values of honeyeater home range is not particularly instructive. It does appear that Melithreptus have larger home ranges than those recorded for other honeyeaters, but lack of comparable methods prevent any strong conclusions. Besides comparisons of numeric results, there are some important trends in common between the P. novaehollandiae studies. The habitat used here was woodland, while that of Pyke and O’Connor (1993) was heath. However, Pyke and O’Connor (1993) noted that many resident birds moved off their home range to feed in adjacent open forest (these were the fixes excluded from home range calculations; resident birds spent 80% of their time in the heath). A similar behaviour was noted here for one P. novaehollandiae (YMYL). This bird had a stable home range within E. baxteri over Xanthorrhoea and various epacrid shrubs. However, it moved a considerable distance (~700 metres) to a (paddock) flowering E. leucoxylon in which it was recorded on numerous occasions (19 out of 106 fixes). It appears likely that the E. baxteri territory was a breeding territory which the bird maintained through the non-breeding season, despite having to move off the territory to find resources (McFarland 2002). Paton (1985) also found that resident P. novaehollandiae moved to nearby areas containing flowering E. leucoxylon when food was scarce on his study site (mainly E. obliqua over flowering shrubs) and Pyke (1989) suggested that the lack of an effect of removal of almost all nectar resources on honeyeater nesting or abundance was due to the birds flying to nearby productive areas to feed on nectar. The other P. novaehollandiae I tracked had home ranges in E. leucoxylon/E. fasciculosa over epacrid shrubs and made few movements outside their home range during this study. Thus, a number of studies in different areas have found that P. novaehollandiae, particularly males, have a home range outside the breeding season (this study, Paton 1979; 1985; Pyke and O'Connor 1993; McFarland 2002) that is small and likely to be similar to their breeding territory (Paton 1979; 1985; McFarland 2002). There is good evidence that movements outside this home range are aimed at supplementing food resources. The non-breeding home range can be considered a territory in that they are stable, defended and give relatively exclusive access to the resident (McFarland 2002).

164

Home range size estimated for Melithreptus in the Mt Lofty Ranges was larger than that of honeyeaters in other published studies, and Melithreptus used larger areas than P. novaehollandiae. The methods used in this study provided similar results for P. novaehollandiae to those of other studies, particularly their trend to maintain an (apparent) breeding territory outside the breeding season and to move outside this territory (probably within about a 1 km radius) to forage.

5.4.2 The small Melithreptus guild There is a trend within the home range and movement data that supports the differences found in morphology within the small Melithreptus guild. The only morphological attribute in which M. brevirostris was smaller than M. lunatus was wing length, and this was one of few morphological attributes in which M. brevirostris was closer to female M. lunatus than male M. lunatus. In this chapter, whenever an effect of species/sex was found on the home range and movement data presented, M. brevirostris was closer to female M. lunatus than male M. lunatus, with the exception of overall MCP, which was larger for M. brevirostris than both M. lunatus sexes. In each other case a continuum from M. brevirostris through female M. lunatus to male M. lunatus was found with the only statistical differences being between M. brevirostris and male M. lunatus. This result reinforces the idea that the small Melithreptus guild is, ecologically, a continuum.

Each of the species/sexes showed an increase in the various home range statistics between the breeding and non-breeding seasons (but with weak evidence for increase in overall MCP). One possible explanation for this increase is lack of resources within a breeding home range during the non-breeding season. In the Mt Lofty Ranges resources are most likely to be limiting to honeyeaters during the Melithreptus non-breeding season (Ford 1977; 1979). Because of their lighter weight, female honeyeaters are more likely to suffer from interference competition, especially during the non-breeding season. Paton (1979) found that during the non-breeding season, P. novaehollandiae females were more likely to move off the breeding area than males, most likely due to interference competition with the male. Some of these females were found feeding in other areas, sometimes on poorer resources (Paton 1979). A similar pattern was documented in P. pyrrhoptera in the Mt Lofty Ranges by Foster (2001). So is this the case with M. lunatus? When expressed as a percentage of overall MCP, female M.

165 lunatus showed a marked increase in both daily MCP (4.99 times) and KH (90% UD 4.28 times) between breeding and non-breeding seasons compared with male M. lunatus (1.02 and 3.62 respectively). While, no evidence of intraspecific interference competition was found, only one M. lunatus pair was found foraging together in both seasons. One likely explanation for this is that the female population was forced from the breeding areas by males during the non-breeding season due to intraspecific, intersexual competition. Perhaps the presence of young males on the parental breeding areas in the non-breeding season increased the chance of intraspecific competition as resources decrease during the non-breeding season. The one pair that remained together over the non-breeding season did not have young birds with them during that time.

The core areas of activity for Melithreptus are likely to correspond to peaks in the availability of their food resources, and these areas are also likely to correspond to peaks in local soil nutrient levels (Recher et al. 1996). A possible test of this hypothesis would be that the core areas of activity in Melithreptus home ranges should be relatively stable through time, and that soil nutrients within these core areas should be higher than non-core areas within the home range. Some level of stability has been established, in that colour-band sightings often occurred within core areas for up to three years. Soil nutrient tests in relation to core areas and home range should be considered for future research on Melithreptus.

Melithreptus brevirostris always moved further and had larger core areas than M. lunatus in both seasons. Melithreptus brevirostris probably move more frequently, further and over larger areas, at least in part, due to their larger group size. However, this is unlikely to be the sole explanation. It is worth considering the importance of E. viminalis to M. lunatus in comparison to M. brevirostris. Eucalyptus viminalis often occurs along drainage lines or as restricted pockets (also often along drainage lines) in areas of locally high soil nutrients compared to most other vegetation communities present in the Mt Lofty Ranges (Ball and Carruthers 1998; Armstrong et al. 2003). Thus, the vegetation type in which M. lunatus was recorded in the highest abundance is also found in restricted areas compared to other vegetation types and M. lunatus group size is likewise likely to be restricted in size. In contrast M. brevirostris do not respond numerically to one particular vegetation type and move over larger areas than M. lunatus. The core areas of activity for M. brevirostris presumably also correspond to

166 peaks in local soil nutrient levels, but perhaps not as productive as areas containing E. viminalis. One piece of evidence provides further support for this hypothesis: more M. lunatus were recorded per hectare (1.2 birds/ha) than M. brevirostris (0.5 birds/ha) in areas where they were present (Chapter 2).

Both M. brevirostris and M. lunatus, were observed in mixed species flocks when foraging outside their core areas. These flocks occasionally included a number of congenerics. Foraging in groups of around seven individuals is common for M. brevirostris, but M. lunatus rarely foraged in groups larger than three in either season. The core areas of M. lunatus were smaller than the core areas of M. brevirostris and M. lunatus foraged in smaller groups within these core areas. Melithreptus lunatus are likely to have knowledge of these core areas, such as which areas are defended and where the highest concentrations of resources are, giving them an advantage over transients. If this knowledge fails to allow them to access sufficient resources, joining a flock of foraging birds gives them a number of advantages. Not only the flocking advantage demonstrated in Chapter 3 but also decreased predation risk to the individual (e.g. Bertram 1978) and increased chance of locating patchy resources (e.g. Giraldeau 1984). Resources within the core areas of a Melithreptus home range may become limiting for two main reasons: a decrease in resources; or an increase in the defence of some of the resources. In the Mt Lofty Ranges a resource limitation for honeyeaters has been demonstrated as most likely during the Melithreptus non-breeding season. At this time flock sizes in Melithreptus are largest, supporting the idea that Melithreptus do use flocking strategically to access resources within the feeding territories of aggressive honeyeaters.

Finally, as an aside, the data collected here provide a test of the hypothesis of Pyke (1980) that Australian honeyeaters travel as flocks as an anti-predator adaptation on the part of individual birds. The flock size of two species of honeyeater with very similar ecology and behaviour was sampled extensively throughout the year at four sites in the Mt Lofty Ranges. The predation pressure experienced by the two species was likely to be identical, but the two species had quite different flock sizes. If predation pressure was responsible for determining flock size in Australian honeyeaters, both species would be expected to have similar flock sizes. Flock size was probably driven by an

167 interaction between movement, foraging behaviour and productivity of core areas (see Section 6.4.3).

Predation was never noted for Melithreptus other than the already me ntioned Kookaburra incident (Section 5.3.1). There were certainly avian predators in the area. All Melithreptus had a similar reaction to the presence of a raptor; they invariably remained completely motionless. Thi s is in contrast to P. novaehollandiae in which numerous individuals would, almost as one, rain down from the adjacent trees to whatever shrubs were available.

5.4.3 Comparison with P. novaehollandiae One outcome of the relatively large home ranges for Melithreptus is clear. In the currently highly fragmented woodlands of south eastern Australia, Melithreptus are at a disadvantage in comparison to P. novaehollandiae (and other species with small home ranges). It is easier to ‘fit’ a small home range into fragme nted native vegetation than to fit a larger one. Further, M. gularis is at an even greater disadvantage if the single bird tracked here is representative and the preferred habitat of Melithreptus, gum woodlands are the most highly fragmented of remaining native vegetation. Some of the most revealing results ar e those summarised by the MCP, both overall and daily, but particularly daily (Figure 5.12). Every day, Melithreptus move over an area 16 times larger than P. novaehollandiae. The fact that Melithreptus use so much more area every day suggests that required resources in some form are distributed diffusely or in widely spaced clumps across the landscape in comparison with the resource requirements of P. novaehollandiae. Time budget data collected during the radio-tracking periods also support this idea (Chapter 6).

Melithreptus are able to cross areas without native vegetation, and thus are not l imited in the dispersal sense of other species such as Climacteris picumnus (Brown Treecreeper: Walters et al. 1999; Cooper and Walter s 2002) or Stipiturus malachurus (Southern Emu-wren: Littlely and Cutten 1994; Wilson and Paton 2004). However, Melithreptus use a larger proportion than P. novaehollandiae of their already la rger home range each day. Undoubtedly, Melithreptus evolved such a strategy in areas of continuous suitable habitat. As suitable habitat becomes fragmented, finding enough of it requires increased use of any bottlenecks or crossing progressively larger areas of

168 unsuitable habitat. Phylidonyris novaehollandiae do not perceive such changes until a much greater level of fragmentation. Thus Melithreptus are likely to respond to fragmentation at a level well before P. novaehollandiae. At this point it is worth considering the results of Chapter 2 which suggested none of the Melithreptus were limited in their abundance in the Mt Lofty Ranges by fragmentation. However, the sites used were not placed randomly across the entire landscape. They were placed randomly (to a degree) within native vegetation. This may have been enough to dilute any fragmentation effect on Melithreptus. If sites were placed across the entire landscape, it is much more likely a fragmentation effect would be found. However, this does not alter the results, which demonstrated no support for an effect of fragmentation on Melithreptus within areas of native vegetation. As large scale clearance of native vegetation stopped in South Australia in 1983 (DENR 1997), any continuing decline of Melithreptus within native vegetation is unlikely to be due solely to fragmentation, and reinforces further the need to investigate the causes of continued decline.

As P. novaehollandiae will not respond to fragmentation at the same level as Melithreptus, they will be able to exploit areas of highly fragmented vegetation (e.g. roadside corridors) more efficiently than Melithreptus. Such areas alone are not viable habitat to species requiring a large home range. If P. novaehollandiae are able to breed in areas like this they will increase their population relative to species requiring larger home ranges. In turn, there may be pressure for successful honeyeaters to disperse into less fragmented areas, especially at a time of year or in a year when resources become limiting. This is likely to increase any competition with Melithreptus through either interference competition with P. novaehollandiae defending feeding territories or exploitative competition with large numbers of P. novaehollandiae impacting on resources used by Melithreptus. Even with a small overlap in feeding substrate, a substantially elevated P. novaehollandiae population (relative to remaining habitat) is likely to exploit some of the resources that Melithreptus previously relied on.

One further change to the landscape that may favour P. novaehollandiae over Melithreptus is woody weed invasion. Melithreptus rely on the areas of most productive woodland (smooth barked gums) and these are the areas most susceptible to weed invasion (Armstrong et al. 2003). Worse (for M. lunatus particularly), weed invasion is particularly prevalent along drainage and creek lines, areas which E. viminalis favours

169 (Armstrong et al. 2003). Melithreptus do not nest, feed or shelter in the shrub layer to any substantial degree. Phylidonyris novaehollandiae, however, use the shrub layer for nesting, shelter and if appropriate, for feeding. Perhaps the most important aspect of this ‘improved’ habitat quality for P. novaehollandiae is the increased provision of nesting sites by woody weeds. As already discussed, P. novaehollandiae has been shown by a number of studies to maintain breeding territories outside of the breeding season. Thus, the invasion of grassy, gum woodlands by woody weeds is likely to increase the year round P. novaehollandiae presence in good Melithreptus habitat.

Extensive areas of grassy woodland with limited shrub layer on good soils could be designated as good Melithreptus habitat. In the past, such areas of good Melithreptus habitat are unlikely to have been monopolised to any extent by the current successful honeyeaters in the Mount Lofty Ranges, P. novaehollandiae and A. carunculata. Since European settlement, good Melithreptus habitat has been preferentially cleared resulting in its current fragmented nature. Further, the relictual patches of good Melithreptus habitat are subject to woody weed invasion increasing their habitat value to the most widespread and abundant honeyeaters remaining in the Mt Lofty Ranges.

5.4.4 Melithreptus gularis The home range of the M. gularis, using any method, was much larger than its smaller congenerics, and therefore much larger than other published honeyeater home range studies. If the tracked bird is representative of the M. gularis population, the effects of fragmentation are likely to be greatly magnified for M. gularis. If Melithreptus need large home range areas due to use of diffuse or widely spaced resources, due to its greater weight M. gularis is even further disadvantaged. The most common group size for the M. gularis during radio-tracking was two birds, although up to six individual M. gularis were recorded (during one fix). That the M. gularis radio-tracked often moved with conspecifics is some evidence that the data collected were representative of M. gularis in the Scott area of the Mt Lofty Ranges.

5.4.5 Residency of individuals Keast (1968b) stated M. lunatus was a resident or local nomad in the Mt Lofty Ranges, the southern race of M. gularis was a resident or undertakes minor local movements associated with flowering and that M. brevirostris was resident in parts of its range and

170 nomadic elsewhere. Most of these statements were supported by the work presented here, except that there was little evidence of nomadism in the results, with individuals from all species resighted at their place of banding over a year later (including one M. gularis, see Appendix 1) and for M. lunatus and M. brevirostris evidence of individuals present within their home range during each month of the year or at least in both breeding and non-breeding seasons. Therefore, a proportion of the Melithreptus population was resident within their home ranges (as determined during the radio- tracking period) for greater than a year, strongly suggesting that at least a proportion of the Melithreptus was not migratory or nomadic. However, female M. lunatus were less likely to be found near their core areas during the non-breeding season than their male conspecifics and M. brevirostris. This result was consistent with other honeyeater studies in which females were more likely to leave the breeding areas in the non- breeding season than male conspecifics (Paton 1979; 1985; Clarke and Clarke 2000; Foster 2001). However, the data collected here were not able to provide any strong indication as to whether female M. lunatus are migrating to other locations or moving locally. If the description ‘local nomad’ could be applied to any member of the small Melithreptus guild it would be female M. lunatus during the non-breeding season. A further possible explanation for female M. lunatus being recorded less in core areas is that they are more secretive than male M. lunatus.

Mortality in mobile birds is likely to be higher as they face unknown quantities of food supply, competition and predation pressure, whereas sedentary birds (presumably) have a good knowledge of each within their home range and particularly core areas. This may account for the shorter time spans over which individual female M. lunatus were sighted compared with male M. lunatus. Further, the clearance of productive land throughout the Mt Lofty Ranges is likely to leave any mobile Melithreptus with fewer options for alternate foraging areas during times of resource limitation (Ford et al. 1993; Paton 2000; Ford et al. 2001; Paton et al. 2004b). This is likely to result in a Melithreptus population that, even if it was migratory or partially migratory in the past, is increasingly sedentary in areas best able to support the remaining population.

171 Chapter 6 BEHAVIOUR OF MELITHREPTUS WITH A FOCUS ON FORAGING

6.1 Introduction

The results of Chapter 5 demonstrated Melithreptus move over a larger area in comparison to Phylidonyis novaehollandiae and other honeyeaters. One reason for this may be that resources required by Melithreptus are distributed diffusely or in widely spaced clumps across the landscape in comparison with the requirements of P. novaehollandiae. If this is the case, Melithreptus are likely to spend more time foraging than P. novaehollandiae, and other honeyeaters, in order to meet their dietary requirements. One of the suggested reasons for the decline of honeyeaters in the woodlands of south-eastern Australia is a decrease in foraging efficiency related to an increase in interspecific competition and a decrease in resources due to the loss of habitat, and particularly the loss of habitat on productive soils (Ford et al. 2001; Oliver 2001; Paton et al. 2004b). Testing such a theory directly would involve quantifying the production of all honeyeater resources (invertebrates, lerp, manna, honeydew and nectar) at a number of sites reflecting the range of fragmentation and soil productivity across the remaining landscape in south-eastern Australia and correlating this with time spent foraging by the honeyeater community present at each site. Problems with scale in assessing honeyeater community at a site have already been highlighted (Chapter 2), increasing the difficulties in testing the theory directly. Removal experiments (e.g. Section 3.2) are able to demonstrate an effect of competition, but are not able to determine if the species of interest is resource limited under normal conditions. However, it is possible to indirectly determine the combined effects of competition and resource levels on the behaviour of a species using time budget data. This approach assumes that an individual foraging from poor resources due to competition and/or lack of adequate resources will spend more of its time foraging than an individual foraging from adequate resources. In assessing the data arising from time budgets, a comparative approach is usually required to establish ‘normal’ values for the populations of interest. This approach was used by Oliver (2001) to determine that within his study Xanthomyza phrygia was not consistently or frequently suffering from a lack of, or problems with access to, food.

172 Oliver (2001) summarised time budget data from nineteen (eighteen plus his own) studies on 14 species of honeyeater. Over all studies and species (and using maximum and minimum values as extra studies where applicable), the ‘average’ honeyeater spends 34.1% (± 3.9%, mean ± standard error) of its time foraging, 59.1% (± 4.1%) of its time resting and 2.9 (± 1.1%) of its time in aggression. A category called ‘flying/other’ made up the rest of the time. Are there problems associated with averaging a broad spectrum of studies that encompass a wide range of geographic, environmental and temporal conditions? Oliver (2001) suggests that meaningful comparisons are difficult, due the data being, ‘collected in different geographic locations, under different climatic conditions and in different years than those used in this study (Oliver 2001)‘. However, due to the wide range of conditions encompassed, the summarised data do provide an indication of the behavioural range exhibited by honeyeaters. So long as not too much emphasis is placed on the actual values, a qualitative comparison can provide useful insights into the populations currently under investigation. Perhaps a more valid criticism of making comparisons with summaries of the literature are the different methods used to classify actions into categories by the different authors. In many studies the proportion of time foraging was probably underestimated as movements of birds between food sources, and searching for food while perching are not included in the foraging category (Oliver 2001). While this is true, the authors generally had legitimate reasons. For example, McFarland (1986a) divided all activities recorded into the following categories: perching (sitting, including time sitting at inflorescences but not probing); moving (moving through vegetation); probing (feeding at the flowers of an inflorescence); and flying (powered or gliding flight). Many of the activities included in each of these categories were classed as foraging by Oliver (2001). McFarland’s (1986a) study had an energetics focus, and hence each of the activities were assigned different energetic benefits and costs. Weathers et al. (1996) also had an energetics focus and split their activity categories similarly to provide a basis for modelling overall energy budgets. Thus, there are two approaches to categorising time budget actions recorded in honeyeaters. An energetic approach (e.g. Collins and Newland 1986; McFarland 1986a; Weathers et al. 1996) in which each activity is lumped into a category best reflecting energetic cost and a comparative approach (e.g. Oliver 2001) in which each activity is lumped into a category best reflecting purpose and compared with other such studies. The first approach generally has its goal in investigating the profitability of food supply, while

173 the second approach has its goal in using time budget data to determine aspects of ecology that may be of importance to conservation. Each is an attempt to be absolute or relative, respectively. While these two approaches do not preclude useful comparisons, they require comparisons to be made cautiously and probably not against a summarised account of the literature. Studies in which it is clear that all time spent in an activity related to foraging were included in a foraging category are summarised below.

Paton (1980) lumped all activities associated with foraging when calculating percent of the day feeding in P. novaehollandiae and found values ranging from 86.8% (during May) to 33.2% (December). Lichenostomus cratitius (Purple-gaped Honeyeater) was found to spend 88% of its time foraging (Paton 1980). Collins and Newland (1986) found that P. novaehollandiae spent between about 60% of its time in non-foraging perching and about 30% of its time foraging in different months. Anthochaera chrysoptera spent more time perching (non-foraging) and less time foraging (about 80% and 10% respectively). Weathers et al. (1996) found P. novaehollandiae spent 24-29% of their active day foraging and 67-73% of the day perched (which equated to resting). Finally, Oliver (2001) found that X. phrygia spent 43.2% of its time foraging, 22.7% resting and 1.8% in aggression. Thus, there is considerable variation in time spent in the three behaviour categories of most importance to conservation; foraging, resting and aggression. Given the variation between studies, perhaps more important is the variation sometimes present within a study and the implications of this to the ecology of honeyeaters. Paton (1985) found that the percent of daylight spend foraging varied seasonally at a site in Victoria, with non-breeding P. novaehollandiae spending about 50% of the day foraging except during autumn when 80% of the day (more than 10 hours per day) was spent foraging. Further, while spending 80% of the day foraging, the birds harvested less food than at other times of the year, consumed less energy than their predicted requirements and lost weight (Paton 1985). Through measurements of the carbohydrate resources available to honeyeaters throughout the year at two sites in Victoria, Paton (1979; 1980; 1985) was able to demonstrate that abundance of P. novaehollandiae and other honeyeaters at the sites, and their breeding and physical condition, relied on carbohydrate resources (nectar, manna or honeydew). It appeared likely that breeding was determined by the profitability of carbohydrate resources available at a site, as breeding only occurred when the quality of carbohydrate resources at a site was high. This occurred during winter and spring when the net energy gains

174 from nectar feeding remained high throughout the day (Paton 1985). When resources were scarce, the number of honeyeaters was reduced and they spent a greater proportion of their time foraging (Paton 1985). Thus the amount of time an individual honeyeater spends foraging provides a good surrogate measure of the quality of resources from which it is foraging. The proportion of time spent foraging was used here to indicate the quality of resources Melithreptus used for foraging and to see if Melithreptus were likely to be resource limited. Comparisons were also made on proportion of time spent resting and in aggression.

Besides comparing Melithreptus behaviour with other honeyeaters to determine if resource limitation appeared likely, another focus of this work was the behaviour of M. brevirostris and M. lunatus occurring in sympatry. The question of how sympatric populations of M. brevirostris and M. lunatus coexist has always been peripheral to studies including these species. Upon completion of a wider study, authors note the high degree of similarity between M. brevirostris and M. lunatus and then look to their results to explain the sympatry (e.g. Keast 1968a; Ford and Paton 1977; Recher et al. 1985; Ford et al. 1986). Often the two species appear different in their use of bark and foliage as feeding substrates (Section 1.5.4). While this difference has not been explicitly stated to provide a mechanism for sympatric coexistence (except perhaps Keast 1968a), a review of the literature suggested this was likely. As summarised in Section 1.5.4, this ‘theory’ failed in the following regards: in some studies M. brevirostris fed from one substrate more than M. lunatus while in others the results were reversed; when the geographic range of a study was limited, M. brevirostris and M. lunatus fed from all substrates in similar proportions; and one study, Paton (1980), found both species changed their foraging substrates dependent on where carbohydrate resources were most rewarding. Therefore the second aim of this chapter was to investigate the foraging behaviour of M. brevirostris and M. lunatus populations occurring in sympatry, and specifically to determine if either species fed more from bark or foliage than the other.

6.2 Methods

Behavioural information and time-budgets were mainly collected on birds during the radio-tracking periods (Table 6.1; for radio-tracking methods see section 5.2). An emphasis was placed on obtaining information on known individuals (colour-banded

175 and/or radio-tagged), but this was not always the case. Behavioural information was recorded at all fixes (point data), but time-budget methods (outlined below) were only satisfactorily established in February 2002. When approaching a radio-tagged bird, behavioural information was collected on sighted Melithreptus, often before the identity of the individual was confirmed. The first behaviour observed was recorded as a point observation, and then, if possible (if the bird was still visible), time-budget information was collected. At some stage, the colour-bands and/or radio-tag were determined, confirming the identity of the bird (as either a radio-tagged bird, colour-banded bird or non colour-banded bird). At this stage, the time-budget was stopped if the individual was not the focal radio-tagged bird, or, if it was, continued for 10 minutes, or until the bird was completely lost to sight. In all cases, appropriate other information was recorded, such as GPS fix, plant species and number of conspecifics detected in the vicinity. All time-budget information was recorded on a digital voice recorder, using code words for each action, while observing the individual through binoculars (Zeiss 10×25B T*P). Each code word represented a change in the bird’s activity, with that activity continuing until the bird changed activity and the next code word was used. Consecutive actions that were identical were recorded (i.e. if the bird’s beak was seen to probe under bark three or four times without the bird changing perch, each probe was recorded as a separate action). Actions recorded during time-budgets are given in Table 6.2 and were exclusive; at no time could an individual be engaged in more than one action, and no other actions were observed during time-budget collection. Due to the height of the birds and distance from which most observations were taken, it was extremely rare that any item of food taken was identified. Therefore, the position of a bird’s beak was the focus of time-budget actions recorded, and if the beak was not visible the action was recorded as lost. Non-flight movement was the least distinct action, at times merging into flight, especially for inter-canopy movements. Other actions were usually distinct and easily distinguished by the methods used.

A macro written for use in Microsoft Excel was later used to transcribe the recordings. A toolbar specific to the data analysis was developed with a button for each action. While listening to the recording, the appropriate button was pushed with a mouse, automatically recording the action and action time. Appendix 4 provides an example of a time budget recording after transcription. The data on an individual (with all data on unknown individuals combined as one extra individual) was combined, and the

176 proportion of time spent in each action or category determined. No minimum time- budget length was imposed on data used in the analyses (e.g. Oliver 2001 used a minimum time of 60 seconds).

Individual was used as a replicate for all statistical analyses, leading to a situation in which there is some level of repeated measures, as some individuals had data recorded in both seasons. However, as all individuals were not recorded in both seasons it was not possible to carry out a repeated measures analysis. Most individuals had data recorded in only one season. Statistical analyses were carried out on certain behavioural categories (aggression, foraging and resting) and foraging substrates for the effects of the small Melithreptus guild and season and for the effects of taxon (Melithreptus and P. novaehollandiae) and season. The effect of species/sex on the major plant species used were also tested statistically. Before any analysis, proportional data were arcsine transformed to better meet the assumption of normality (Zar 1984). Means and standard errors presented are based on proportional data, not transformed data.

Table 6.1: Days per month on which behavioural data could have been recorded in each area

Season Month Kaiser Newland Scott Scott Creek All Sites January 3 5 8 February 1 22 23 March 17 17 Non-breeding April 3 31 16 50 May 12 5 1 18 June 8 17 25 Total 1 23 95 22 141 July 33 33 August 1 9 3 13 September 5 8 13 Breeding October 15 1 7 23 November 29 1 30 December 14 2 16 Total 21 1 100 6 128 Both Seasons Total 22 24 195 28 269

177 Table 6.2: Foraging actions recorded

Most actions are derived from other sources (Recher et al. 1985; Ford et al. 1986; Oliver 2001). Non-flight movement and searching were included in the foraging category if preceded and followed by a foraging action, otherwise as other and as resting respectively. Interaction was aggression or other. In the text, ‘Observation time’ is the summed time of all actions except lost, ‘Foraging time’ is the summed time of all actions falling under the foraging category (including Non-flight movement and searching where appropriate) except lost, and ‘Substrate time’ is the summed time of all actions represented in the Substrate column. Action Category Substrate Description and Notes Chased Aggression chased by another bird (other species noted when possible) Chasing Aggression chases another bird (other species noted when possible) Calling Other Sherp call Other ‘sherp’ call (Slater et al. 1989) of M. lunatus only Flying Other Drinking Foraging only recorded on one occasion for M. brevirostris Gleaning Bark Foraging bark beak on bark Gleaning Foliage Foraging foliage beak on foliage Hang Glean Foraging foliage only used here for foliage – stationary bird with beak on foliage while hanging Hawk Foraging hawk flying bird takes a flying insect Nectary (Acacia) Foraging flower beak at extra-floral nectary Probe Flower Foraging flower beak at flower Probing under bark Foraging bark beak under bark Twig Foraging bark beak on twig Non-flight movement Context dependent category mostly foraging. bird changes position (usually ‘hops’); another action recorded on stopping Searching Context dependent category mostly foraging. bird actively looking around, almost always during foraging Interaction Context dependent category aggression or other. interacts with another bird of the same species (type of interaction noted) Bathing in leaves Grooming Preening Grooming Stropping Grooming wipes beak back and forth over twig or branch Lookout Resting perched prominently and looking around; very li ttle o verlap with searching – quite a different action Resting Resting not moving and not searching At nest Breeding bird sitting on nest or visiting nest Feed fledgling Breeding bird feeds juvenile out of nest Feed nestling Breeding bird feeds chicks Lost Lost if the beak of the bird was not visible the time was classified as lost

178 6.3 Results

6.3.1 Summary In total 100,600 seconds (28 hours) of data were recorded on 81 known individual birds including 50,487 actions. The number of individuals, tracks and seconds recorded in each season for each species is summarised in Table 6.3. Statistically, there was no effect of species on proportion of observation time recorded as lost during the breeding

(F2,33=0.7369; P=0.4863) or non-breeding (F2,41=0.1740; P=0.8409) seasons, so time recorded as lost was removed from all results. In the breeding season, M. brevirostris and male M. lunatus had the shortest track lengths, followed by female M. lunatus then M. gularis. In the non-breeding season, M. brevirostris was shortest, then male M. lunatus, female M. lunatus and P. novaehollandiae. Statistically, there was no effect of species on track length (F3,31=1.4155; P=0.2569) during the breeding season but during the non-breeding season P. novaehollandiae had longer tracks than both M. brevirostris and male M. lunatus (F3,39=5.9447; P=0.0019) but all other species/sexes had similar track lengths. The effect of this on time budget data was probably small, but is unknown. Data on unknown individuals were included in most analyses as one extra individual, except when examining the small Melithreptus guild, when unknown M. lunatus were obviously of unknown sex and were therefore excluded from the analyses.

There was an effect of radio-tag on proportion of time spent foraging and resting (Table 6.4). This effect was not in the direction expected (if radio-tags were imposing an energetic penalty on the birds due to carrying extra weight) with radio-tagged birds spending less time foraging and more time resting. This may have resulted from the birds finding the tags unpleasant to carry, and therefore they spent more time not moving. However, in this case it could be expected that the birds would spend more time grooming in an attempt to remove the tag, which was not the case (Table 6.4). Thus, it appears that the effect of radio-tags on proportion of time spent foraging and resting was due to an improved knowledge of the activity of radio-tagged individuals (i.e. it is hard to detect honeyeaters that are not active when they are not radio-tagged).

All species used the substrates expected, based on the literature. A further foraging action observed was ‘probing foliage’, in which a bird probes between two leaves that

179 are stuck together. However, this was sometimes hard to distinguish from gleaning foliage, was not recorded consistently from the start and has therefore been lumped with gleaning foliage f or all results. All Melithreptus species used this feeding action at some time.

An important part of Melithreptus foraging involved actively searching for food (Figure 6.4, pg 187). All Melithreptus spent a large proportion of their foraging time in either non-flight movement or actively searching. The continual changing of perch and searching (appeared to) enable Melithreptus to observe a large portion of the canopy through which they were foraging and took them over a large number of substrates in a short period of time. All the foraging actions were included in the foragin g category for analysis of propo rtion of time spent foraging. However, due to the feeding regime, it was not possib le to define portions of foraging time as feeding from, say, foliage. It was common for an individual to, in a very short space of time, make a n umbe r of foraging actions from different substrates (e.g. Appendix 4). Therefore, in order to compare the proportion of time each species spent foraging from different substrates only time actually feeding from a substrate was used. Actions included in subs trate time are represented in the subs trate column of Table 6.2.

No attempt was made to differentiate data for breeding birds (as opposed to breeding and non-breeding season) as breeding behaviour represented a continuum from ‘normal’ parentage to occasional helper, particularly for M. brevirostris, but also fo r M. lunatus. There were also birds not seen to participate in breeding at all during the b reeding season. Due to this continuum, sample size was not great enough for ‘normal’ breeding birds. For example, of 71 fixes on M. brevirostris RMRR it was sitting on a nest twice but only visited the nest tree on six other occasions, and only visited the nest on two of these to feed a sit ting bird. Another example, male M. lunatus RMYY was associated with a breeding pair of M. luna tus, male RMBG and an unbanded (presumably) female. Of 57 records on RMYY 25% were in the nest tree, but RMYY was not confirmed sitting on the nest at any stage and would often spend large portions of time feeding (apparently alone) some 200 metres away.

180 Table 6.3: Summary of time-budget data

a) Known: colour-banded individuals Species/sex Season Individuals Tracks Seconds Mean Track Seconds M. brevirostris Breeding 18 96 13981 146 Non-breeding 17 84 7861 94 M. lunatus ♀ Breeding 4 13 2042 157 Non-breeding 6 49 5688 116 M. lunatus ♂ Breeding 9 106 15528 146 Non-breeding 14 120 12459 104 M. gularis Breeding 2 66 14476 219 Non-breeding P. novaehollandiae Non-breeding 4 39 13283 341 b) Unknown: individuals whose identity was not known, and therefore the actual number of individuals is not known. The data from all unknown individuals were pooled as one extra individual in most analyses. Species/sex Season Tracks Seconds Mean Track Seconds M. brevirostris Breeding 40 4118 103 Non-breeding 104 4565 44 M. gularis Breeding 8 961 120 Non-breeding 8 1410 176 M. lunatus Breeding 18 1848 103 Non-breeding 27 2323 86 P. novaehollandiae Non-breeding 1 59 59

Table 6.4: Effect of radio-tags on time spent foraging and resting

Individuals, mean seconds per individual ± standard error are as follows; Not radio-tagged: 56, 478 ± 104; and radio-tagged: 27, 2248 ± 490. Radio-tagged birds spent proportionally less time foraging and more time resting than birds without radio-tags. There was no difference in the proportion of time spent grooming between birds with and without radio-tags. Proportion Foraging Proportion Resting Proportion Grooming Not Radio-tagged 0.82 0.02 0.071 Radio-tagged 0.67 0.15 0.074 Both 0.77 0.06 0.072 df 82 82 82 t 3.319 -3.911 -0.472 P 0.0013 0.0002 0.6381

6.3.2 Behaviour of the small Melithreptus guild

6.3.2.1 Behaviour category All species/sexes spent a large proportion of their time in both seasons foraging (Breeding M. brevirostris 76%, M. lunatus ♀ 56% and M. lunatus ♂ 69%; Non- breeding 82%, 85% and 87%) and spent a statistically larger proportion of time foraging

181 during the non-breeding season. All species/sexes spent a larger proportion of time resting during the breeding season (M. brevirostris 5.7%, M. lunatus ♀14.4% and M. lunatus ♂ 10.8%) than the non-breeding season (1.6%, 0.0% and 0.03%), the difference supported statistically. Little time was spent in aggression (Breeding M. brevirostris 0.2%, M. lunatus ♀ 0.7% and M. lunatus ♂ 1.2%; Non-breeding 0.1%, 0.1% and 1.4%). Statistically male M. lunatus spent more time in aggressive acts than M. brevirostris, while female M. lunatus spent a statistically similar amount of time in aggressive acts to both male M. lunatus and M. brevirostris with no difference between seasons.

Proportion of time spent in the other main behaviour categories were grooming (Breeding M. brevirostris 7.8%, M. lunatus ♀ 14.4% and M. lunatus ♂ 11.5; Non- breeding 8.0%, 8.1% and 1.8%) and flying (Breeding M. brevirostris 5.1%, M. lunatus ♀ 5.0% and M. lunatus ♂ 5.2%; Non-breeding 6.5%, 4.5% and 6.1%).

182 Figure 6.1: Proportion of observation time (mean ± se) spent in each behaviour category by the small Melithreptus guild

br – breeding season; nbr – non-breeding season. Individuals, mean seconds per individual ± standard error are as follows. Breeding M. brevirostris: 19, 828±323; M. lunatus ♀: 4, 474±208; M. lunatus ♂: 9, 1490±643. Non-breeding M. brevirostris: 18, 621±228; M. lunatus ♀: 6, 806±441; M. lunatus ♂: 13,

844±386. Foraging: there was no interaction between species/sex and season (F2,63=1.1062; P=0.3372), an

effect of season (F1,63=7.4332; P=0.0083) but no effect of species/sex (F2,63=0.7659; P=0.4692). Melithreptus spent a larger proportion of time foraging during the non-breeding season than during the

breeding season. Resting: there was no interaction between species/sex and season (F2,63=0.494;

P=0.6125), an effect of season (F1,63=4.6135; P=0.0356) but no effect of species/sex (F2,63=0.4487; P=0.6405). Melithreptus spent a smaller proportion of time resting during the non-breeding season than during the breeding season. Aggression: There was no interaction between species/sex and season

(F2,63=0.1921; P=0.8257), no effect of season (F1,63=0.0937; P=0.7606) but a weak effect of species/sex

(F2,63=3.1291; P=0.0506) on proportion of time spent in aggression. Melithreptus brevirostris spent a smaller proportion of time than male M. lunatus in aggression, but female M. lunatus spent a similar proportion of time involved in aggression to both M. brevirostris and male M. lunatus.

0.9

0.8

0.7

vation time 0.6 r

e M. brevirostris s b 0.5 M. lunatus ♀ o f M. lunatus ♂ 0.4

0.3 oportion o r P 0.2

0.1

0 brnbrbrnbrbrnbrbrnbrbrnbrbrnbrbrnbr

Aggression Breeding Flying Foraging Grooming Other Resting Behaviour Category & Season

6.3.2.2 Substrate time Figure 6.2 compares the proportion of substrate time each species/sex spent foraging from each substrate. All species/sexes spent a smaller proportion of substrate time foraging from bark during the breeding (M. brevirostris 15%, M. lunatus ♀ 21% and M. lunatus ♂ 14%) than the non-breeding season (40%, 34% and 48%), with the difference

183 supported statistically. There was no statistical effect of species/sex on the proportion of substrate time spent feeding from bark.

All species/sexes spent a larger proportion of substrate time foraging from flowers during the breeding (M. brevirostris 42%, M. lunatus ♀ 11% and M. lunatus ♂ 38%) than the non-breeding season (9%, 4% and 8%), with the difference supported statistically. There was no statistical effect of species/sex on the proportion of substrate time the different species spent feeding from flowers.

Melithreptus brevirostris spent a larger proportion and M. lunatus a smaller proportion of substrate time foraging from foliage during the breeding (M. brevirostris 43%, M. lunatus ♀ 68% and M. lunatus ♂ 47%) than the non-breeding season (51%, 62% and 43%), but the differences were not supported statistically. There was no statistical effect of species/sex on the proportion of substrate time the different species spent feeding from foliage.

Hawking was not tested due to inadequate sample size. Melithreptus hawking was recorded on 15 occasions in 3 M. brevirostris, 5 male M. lunatus and 1 M. gularis. It was not recorded for any female M. lunatus.

184 Figure 6.2: Proportion of substrate time (mean ± se) spent feeding from each substrate during breeding and non-breeding season by the small Melithreptus guild

Includes all actions represented in the substrate column of Table 6.2. Individuals, mean seconds per individual ± standard error are as follows. Breeding M. brevirostris: 19, 235±96; M. lunatus ♀: 4, 43±9; M. lunatus ♂: 9, 261±123. Non-breeding M. brevirostris: 18, 195±74; M. lunatus ♀: 6, 207±109; M.

lunatus ♂: 14, 215±86. Bark: there was no interaction between species/sex and season (F2,64=0.4003;

P=0.6718), an effect of season (F1,64=7.4566; P=0.0082) but no effect of species/sex (F2,64=0.1579; P=0.8542). All species spent more time feeding from bark in the non-breeding season than in the breeding

season. Flowers: there was no interaction between species/sex and season (F2,64=0.9273; P=0.4009), an

effect of season (F1,64=8.5336; P=0.0048) but no effect of species/sex (F2,64=1.4973; P=0.2315). Foliage:

there was no interaction between species/sex and season (F2,64=0.3221; P=0.7528), no effect of season

(F1,64=0.0776; P=0.7814) and no effect of species/sex (F2,64=0.7993; P=0.4541). Hawking was not tested statistically.

0.9

0.8

0.7

0.6 trate time 0.5 M. brevirostris ubs M. lunatus ♀ 0.4 M. lunatus ♂ on of s 0.3 oporti r P 0.2

0.1

0 Breeding Non- Breeding Non- Breeding Non- Breeding Non- breeding breeding breeding breeding

Bark Flower Foliage Hawk Substrate and Season

6.3.3 Melithreptus gularis The results from three M. gularis during the breeding season showed similar proportions of time allocated to behavioural categories as for the two smaller Melithreptus (Figure 6.3), although M. gularis spent even more time foraging (80%) and less time resting (3%) than the smaller Melithreptus. Two juvenile birds were seen in the vicinity of the radio-tracking area, but no time-budgeted M. gularis were seen to engage in breeding activity. The foraging of M. gularis was similar to M. brevirostris (Figure 6.4), displaying the same trends of a greater proportion of substrate time on

185 flowers (56%), than gleaning foliage (24%), or probing under bark (19%). Time spent looking for food through non-flight movement and active searching was also similar to M. brevirostris. Melithreptus gularis spent about twice as long hawking as M. brevirostris (but less than 1% of foraging time).

186 Figure 6.3: Proportion of observation time (mean ± se) spent in each behaviour category in the breeding season by Melithreptus, including Melithreptus gularis data

Individuals, mean seconds per individual ± standard error are as follows. Melithreptus brevirostris: 19, 828±323; M. lunatus: 14, 1209±428; M. gularis: 3, 4058±3474.

0.90

0.80

0.70 e m i t

n 0.60 o i at

rv 0.50 M. brevirostris se M. lunatus ob

of 0.40 M. gularis on i

ort 0.30 op r P 0.20

0.10

0.00 Aggression Flying Foraging Preening Resting Other Breeding Behaviour

Figure 6.4: Proportion of foraging time (mean ± se) spent in each foraging action in the breeding season by Melithreptus, including Melithreptus gularis data

Individuals, mean seconds per individual ± standard error are as follows. Melithreptus brevirostris: 19, 538±201; M. lunatus: 14, 627±245; M. gularis: 3, 2937±2439.

0.50

0.45 0.40

time 0.35 ng

gi 0.30 a

r M. brevirostris fo

f 0.25 M. lunatus o

n M. gularis 0.20 tio r 0.15 opo r P 0.10 0.05

0.00

k e k y t r g g ar g an r en rk b a le aw ta we hin li g c m lo r ba c Twi g fo g H e ve f in g n N o de ear n a ng n S in H m i u lea ht ob ean g ng G l li Pr i G -f ob n Pr No Foraging action

187 6.3.4 Comparison of Melithreptus behaviour with P. novaehollandiae in the non- breeding season

6.3.4.1 Behaviour category Phylidonyris novaehollandiae spent a smaller proportion of time foraging (56%) and a much greater proportion resting (34%) than Melithreptus (84% and 1.8%, respectively) (Figure 6.5). There was no difference in the proportion of time the two taxa spent in aggression (Melithreptus 0.6% and P. novaehollandiae 0.3%).

Figure 6.5: Proportion of observation time (mean ± se) spent in each behaviour category by Melithreptus and P. novaehollandiae

Foraging includes all actions in the foraging category (Table 6.2). Individuals, mean seconds per individual ± standard error are as follows. Melithreptus: 39, 782±179; P. novaehollandiae: 5, 2428±1150.

Foraging: t42 = 2.708, P = 0.0098. Resting: t42 = -4.715, P < 0.0001. Aggression: t42 = 0.327, P = 0.7453.

1.0

0.9

0.8 e 0.7 n tim 0.6 rvatio e Melithreptus 0.5 P. novaehollandiae

on of obs 0.4

oporti 0.3 r P 0.2

0.1

0.0 Aggression Flying Foraging Grooming Resting Other Behaviour Category

6.3.4.2 Substrate time Melithreptus spent a larger proportion of substrate time foraging from bark than P. novaehollandiae (Figure 6.6, Melithreptus 41% and P. novaehollandiae 31%), a smaller proportion from flowers (8% and 43%), a larger proportion from foliage (50% and 21%) and a smaller proportion hawking (0.1% and 5.6%). Statistically, a greater proportion of substrate time was spent by P. novaehollandiae at flowers and hawking,

188 but there was no difference in the proportion of time spent foraging from bark or foliage (Figure 6.6).

Figure 6.6: Proportion of substrate time (mean ± se) spent on each substrate by Melithreptus and P. novaehollandiae

Individuals, mean seconds per individual ± standard error are as follows. Melithreptus: 39, 229±50; P. novaehollandiae: 5, 157±38. Bark: t42 = 0.525, P = 0.602. Flower: t42 = -4.100, P = 0.0002. Foliage: t42 =

1.574, P = 0.1228. Hawk: t42 = -9.064, P < 0.0001.

0.7

0.6

e 0.5 e tim t

tra 0.4 bs

u Melithreptus P. novaehollandiae 0.3 tion of s r opo r

P 0.2

0.1

0.0 Bark Flower Foliage Hawk Substrate

6.3.5 Aggression The following summary of aggression is based on two datasets, one from time budget data (Table 6.5), the other from point records (Table 6.6). While there is overlap, time budget data did not consistently identify the other species involved in aggressive encounters and there were aggressive encounters observed on focal individuals outside recording of time budgets. The overall proportion of time spent in aggression has already been summarised (6.3.2.1 and 6.3.4.1).

Individual M. brevirostris were attacked (chased or displaced) 3.6 times an hour during the breeding season and 4.6 times an hour in the non-breeding season (Table 6.5). Phylidonyris novaehollandiae accounted for most of the attacks (54% during the breeding season and 94% during the non-breeding season. Table 6.6). Only one M. brevirostris attacked any other individual, a Lichenostomus chrysops on a single

189 occasion in the breeding season. Only one other (unknown) M. brevirostris was seen to attack another individual, a M. brevirostris during the non-breeding season.

Female M. lunatus were attacked 2.5 times an hour during the non-breeding season. No attacks on focal female M. lunatus were recorded in the breeding season time budgets. Phylidonyris novaehollandiae accounted for most of the attacks (100% during the breeding season and 37.5% during the non-breeding season). Female M. lunatus were not recorded attacking other individuals during time budgets in either season, but they were recorded in seven aggressive acts against five other species in the breeding season and in three aggressive acts against two other species in the non-breeding season.

Male M. lunatus attacked other species 6.3 times an hour during the breeding season and 1.5 times an hour during the non-breeding season. They were themselves attacked 6.3 times an hour during the breeding season and 3.9 times an hour during the non- breeding season. Phylidonyris novaehollandiae accounted for most of the attacks (63% during the breeding season and 100% during the non-breeding season). Male M. lunatus attacked 22 individuals from five other species during the breeding season. Of those attacks, 55% were directed against P. novaehollandiae and 27% against Anthochaera carunculata. During the non-breeding season male M. lunatus attacked three individuals from two other species, Pardalotus striatus and Acanthiza lineata.

Melithreptus gularis was attacked 4.4 times an hour and attacked other individuals 0.5 times an hour during the breeding season. Phylidonyris novaehollandiae accounted for 65% of attacks on M. gularis. Melithreptus gularis were observed attacking one M. lunatus during the breeding season.

Focal Phylidonyris novaehollandiae initiated aggressive acts 1.3 times per hour in the non-breeding season against a range of species including M. brevirostris. 53% of attacks by P. novaehollandiae were directed against other P. novaehollandiae. Phylidonyris novaehollandiae were attacked 0.8 times an hour, with the one record of an attack on focal P. novaehollandiae coming from Anthochaera carunculata.

190 Table 6.5: Hourly rate of aggressive interactions in each season

n is number of individuals, acts is number of aggressive acts and rate is the rate per hour for that species/sex in that season. Def: focal individual either chased or displaced by another individual. Off: focal individual either chased or displaced another individual. Breeding Non-breeding n acts rate n acts rate Species/sex off def off def off def both off def off def off def both M. brevirostris 1 4 1 18 0.2 3.6 3.8 5 16 4.6 4.6 M. lunatus ♀ 2 4 2.5 2.5 M. lunatus ♂ 3 2 27 27 6.3 6.3 12.6 2 7 5 13 1.5 3.9 5.4 M. gularis 1 2 2 19 0.5 4.4 4.9 P. novaehollandiae 2 2 5 3 1.3 0.8 2.2

191 Table 6.6: Other species involved in aggression with Melithreptus in each season

Def.: focal individual being attacked by other species. Off.: focal individual being aggressive to other species. Individuals observed in aggressive acts were 22 M. brevirostris, 12 female M. lunatus, 19 male M. lunatus, 3 M. gularis and 5 P. novaehollandiae. Other species are listed in decreasing order of number of aggressive encounters. % P. novaehollandiae is the percent of that species records, within season and aggression type as indicated, that involved P. novaehollandiae. Breeding Non-breeding M. brevirostris M. lunatus ♀ M. lunatus ♂ M. gularis M. brevirostris M. lunatus ♀ M. lunatus ♂ P. novaehollandiae Other Species def off def off def off def off def off def off def off def off Phylidonyris novaehollandiae 14 4 2 19 12 11 34 3 12 10 Anthochaera carunculata 2 6 6 1 1 1 Lichenostomus penicillatus 4 3 2 2 2 1 Melithreptus lunatus 4 1 1 Acanthorhynchus tenuirostris 5 Lichenostomus chrysops 1 1 1 1 Melithreptus brevirostris 2 2 Acanthiza lineata 1 2 Phylidonyris pyrrhoptera 1 1 1 Glossopsitta porphyrocephala 1 1 Pardalotus striatus 1 1 Colluricincla harmonica 1 Falcunculus frontatus 1 Melithreptus gularis 1 Pachycephala pectoralis 1 Phylidonyris albifrons 1 Pomatostomus superciliosus 1 Rhipidura fuliginosa 1 Total aggressive acts 26 1 4 7 30 22 17 1 36 0 8 1 12 3 1 19 Number of other species 6 1 1 5 5 5 6 1 3 0 5 1 1 2 1 5 % P. novaehollandiae 53.8 0.0 100.0 28.6 63.3 54.5 64.7 0.0 94.4 0.0 37.5 0.0 100.0 0.0 0.0 52.6

192 6.3.6 Distribution of foraging action times of honeyeaters feeding from different substrates The amount of time a bird’s beak spent on each substrate was used to represent a foraging action. Based on this data, when feeding from flowers, honeyeaters face a more predictable resource than when foraging from bark or foliage (Figure 6.7). The distribution of foraging action times when foraging from bark and foliage are platykurtic and positively skewed in relation to flowers. In particular, the distribution of foraging times for bark and foliage are positively skewed, with a high proportion of actions taking considerably longer than with a flower. Only around 10% of foraging actions at flowers lasted over 2 seconds, although this was 25% for M. gularis and as little as 3% for P. novaehollandiae. When foraging from bark over 30% of foraging actions by Melithreptus lasted over 2 seconds, whereas only 2% of P. novaehollandiae records did. When foraging from foliage around 40% of honeyeater foraging actions lasted longer than 2 seconds.

193 Figure 6.7: Distribution of foraging action times from; a) Bark, b) Flowers, c) Foliage for each species

Number of seconds of substrate time for M. brevirostris: 5146 seconds, M. lunatus ♀: 1413 seconds, M. lunatus ♂: 5342 seconds, M. gularis 3591 seconds and P. novaehollandiae 715 seconds.

a) Bark

0.5 s on

i 0.4 t c a ng i

g 0.3 a r o f of

n 0.2 o i t or

op 0.1 r P

0 0.25 0.5 1 2 4 8 16 32 64 128 Action time category (seconds) M. brevirostris M. lunatus ♀ M. lunatus ♂ M. gularis P. novaehollandiae b) Flowers

0.5 s on

i 0.4 t c a ng i

g 0.3 a r o f of

n 0.2 o i t or

op 0.1 r P

0 0.25 0.5 1 2 4 8 16 32 64 128 Action time category (seconds) M. brevirostris M. lunatus ♀ M. lunatus ♂ M. gularis P. novaehollandiae c) Foliage

0.5 s on

i 0.4 t c a ng i

g 0.3 a r o f of

n 0.2 o i t or

op 0.1 r P

0 0.25 0.5 1 2 4 8 16 32 64 128 Action time category (seconds) M. brevirostris M. lunatus ♀ M. lunatus ♂ M. gularis P. novaehollandiae

194 6.3.7 Use of Plant Species

6.3.7.1 Summary Melithreptus were recorded in eucalypts on 96.5% of all fixes (M. brevirostris 95.3%, M. lunatus 97.4% and M. gularis 98.0%). Phylidonyris novaehollandiae were recorded in eucalypts on 54.9% of fixes.

Melithreptus brevirostris were recorded in the following eucalypts: E. baxteri, E. cosmophylla, E. diversifolia, E. fasciculosa, E. incrassata, E. leucoxylon, E. obliqua, E. odorata, E. viminalis and a non-local eucalypt. Melithreptus brevirostris were also recorded in Acacia paradoxa, A. pycnantha, Allocasuarina verticillata, Astroloma conostephioides, Astroloma humifusum, Brachyloma ericoides and Callistemon rugulosus.

Melithreptus lunatus were recorded in the following eucalypts: E. baxteri, E. camaldulensis, E. diversifolia, E. fasciculosa, E. incrassata, E. leucoxylon, E. obliqua, E. odorata and E. viminalis. Melithreptus lunatus were also recorded in Acacia pycnantha, A. retinodes, Allocasuarina verticillata, Amyema miquelii, Banksia marginata, Callistemon rugulosus and Xanthorrhoea semiplana.

Melithreptus gularis were recorded in the following eucalypts: E. camaldulensis, E. fasciculosa, E. leucoxylon, E. odorata and a non-local eucalypt. Melithreptus gularis were also recorded in Acacia paradoxa and Amyema miquelii.

Phylidonyris novaehollandiae were recorded in the following eucalypts: E. baxteri, E. fasciculosa, E. leucoxylon and E. viminalis. Phylidonyris novaehollandiae were also recorded in Acacia paradoxa, A. pycnantha, Astroloma conostephioides, Astroloma humifusum, Callitris sp., Correa reflexa, Grevillea lavandulacea, Olea europaea and Xanthorrhoea semiplana.

6.3.7.2 Use of plant species by the small Melithreptus guild Data for plant use were limited to the Scott area in order to maintain a reasonable sample size of plant use by individuals in each species and season. In order to achieve a

195 sample approaching normality after transformation, individuals with records in only one plant species were removed from the dataset before analysis. The maximum time in which an individual was recorded in only one plant species was 7.2 minutes for M. lunatus (E. leucoxylon) and 2.9 minutes for M. brevirostris (E. fasciculosa). No M. gularis or P. novaehollandiae were recorded in only one plant species.

All Melithreptus species/sexes used E. leucoxylon most often for foraging in both seasons except for M. brevirostris in the non-breeding season in which E. fasciculosa was the most commonly used foraging plant species (Figure 6.8). Melithreptus lunatus appeared to use E. viminalis more than M. brevirostris, as might be expected given the results of Chapter 2. Melithreptus brevirostris appeared to use E. fasciculosa more than M. lunatus, especially in the non-breeding season, but this was not supported statistically. Melithreptus lunatus (both sexes) foraged more from E. viminalis than M. brevirostris regardless of season. All of the small Melithreptus guild foraged more from E. viminalis in the non-breeding season than the breeding season.

196 Figure 6.8: Mean proportion (± s.e.) of foraging fixes in various plant species used by the small Melithreptus guild in the Scott area

Scott area data only. Eucalyptus leucoxylon: blue gum; E. fasciculosa: pink gum, E. viminalis: manna gum; E. obliqua and E. baxteri: stringybark. Other were mostly Acacia paradoxa for M. brevirostris and A. pycnantha for M. lunatus. Individuals, mean foraging fixes per individual ± standard error are as follows: Breeding M. brevirostris 15, 10.1 ± 2.8; female M. lunatus 4, 5.3 ± 1.4; and male M. lunatus 8, 18.4 ± 5.5; and Non-breeding M. brevirostris 7, 5.7 ± 1.4; female M. lunatus 3, 12.7 ± 1.9; male M. lunatus 7, 10.0 ± 3.2. There was no statistical interaction or effect of season and Melithreptus species/sex

on proportion of foraging fixes in E. leucoxylon (interaction: F2,38=0.1184, P=0.8887, season:

F1,38=0.7225, P=0.4006; and species/sex: F2,38=0.1398, P=0.8700), E. fasciculosa (interaction:

F2,38=0.3910, P=0.6790, season: F1,38=0.3394, P=0.5636; and species/sex: F2,38=2.1949, P=0.1253),

stringybark (E. obliqua and E. baxteri, interaction: F2,38=0.7993, P=0.4570, season: F1,38=0.1415,

P=0.7089; and species/sex: F2,38=0.4868, P=0.6184) or other plant species (interaction: F2,38=0.9791,

P=0.3849, season: F1,38=0.1350, P=0.7153; and species/sex: F2,38=0.2177, P=0.8053). There was no statistical interaction of season and Melithreptus species/sex on proportion of foraging fixes in E.

viminalis (F2,38=0.8944, P=0.4173), but there was an effect of season (F1,38=5.006, P=0.0313) and

species/sex (F2,38=5.8073, P=0.0063).

0.8

0.7 xes i 0.6 f g

gin 0.5

ra M. brevirostris o

f 0.4 M. lunatus ♀ of M. lunatus ♂ on

i 0.3 t or 0.2 op r P 0.1

0 on- on- on- on- on- eeding eeding eeding eeding eeding eeding eeding eeding eeding eeding N N N N N br br br br br Br Br Br Br Br blue gum pink gum manna gum stringybark other Plant species and Season

6.3.7.3 Use of plant species by Melithreptus gularis Melithreptus gularis was recorded foraging in E. leucoxylon (a bit more) and E. fasciculosa (a bit less) in similar proportions to the two smaller Melithreptus (Figure 6.9). There were no records of M. gularis foraging in E. viminalis or stringybark, despite each being dominant (stringybark) or present (E. viminalis) within the overall MCP of the two M. gularis for which data were recorded. The M. gularis, in fact,

197 roosted in an area dominated by E. baxteri with three other conspecifics. The most common species represented in the ‘other’ category were E. odorata and a non-local eucalypt planted in a revegetated area.

Figure 6.9: Mean proportion (± s.e.) of foraging fixes in various plant species used by Melithreptus in the Scott area

Scott area data only. Eucalyptus leucoxylon: blue gum; E. fasciculosa: pink gum, E. viminalis: manna gum; E. obliqua and E. baxteri: stringybark. Other were mostly a non-local eucalypt and E. odorata for M. gularis. Individuals, mean foraging fixes per individual ± standard error are as follows: M. brevirostris 24, 6.8 ± 1.7; M. lunatus 14, 12.2 ± 5.1; and M. gularis 2, 48 ± 42.

0.9

0.8

s 0.7 xe i 0.6 aging f

r M. brevirostris

o 0.5

f M. lunatus of 0.4 M. gularis on i t 0.3

opor 0.2 Pr 0.1

0 blue gum pink gum manna gum stringybark other Plant species

6.3.7.4 Comparison of Melithreptus plant use with P. novaehollandiae plant use in the non-breeding season Melithreptus foraged from gum eucalypts more and stringybark and other species (mainly Epacrid shrubs) less than P. novaehollandiae (Figure 6.10). Focal P. novaehollandiae were not recorded foraging from E. viminalis, although only one individual had E. viminalis within its overall MCP. Statistical tests were weakened by a lack of normality following transformation, as individuals were limited to plant species that occurred in their home range, leaving a number of individuals with no records for some plant species. The only statistical difference was a greater use of other plant species by P. novaehollandiae than Melithreptus.

198 Figure 6.10: Mean proportion (± s.e.) of foraging fixes in various plant species used by Melithreptus and P. novaehollandiae in the Scott area

Scott area data only. Eucalyptus leucoxylon: blue gum; E. fasciculosa: pink gum, E. viminalis: manna gum; E. baxteri: stringybark. Other were mostly epacrid shrubs, Acacia paradoxa and A. pycnantha for P. novaehollandiae. Individuals, mean foraging fixes per individual ± standard error are as follows:

Melithreptus 38, 4.5 ± 1.0; and P. novaehollandiae 5, 31.2 ± 7.8. E. leucoxylon: t41=0.702, P=0.4866. E.

fasciculosa: t41=1.022, P=0.313. E. viminalis, no P. novaehollandiae records. E. baxteri: t41=-1.711,

P=0.0946. Other: t41=-4.238, P=0.0001.

0.6

0.5 s xe i f

g 0.4 gin ra

o Melithreptus f 0.3

of P. novaehollandiae on i t

or 0.2 op r P 0.1

0 blue gum pink gum manna gum stringybark other Plant species

6.3.7.5 Proportion of substrate time by plant species Using all Melithreptus in both seasons, the availability of resources from each substrate in the main species of eucalypt used are evident (Figure 6.11). Resources available on E. fasciculosa were mainly from flowers and foliage. Eucalyptus leucoxylon provided resources from foliage, bark and flowers. Eucalyptus viminalis provided resources mainly from bark and foliage and stringybark provided resources mainly from bark but also from foliage. Melithreptus took resources from bark and foliage of all species, but floral resources were more important from E. fasciculosa and E. leucoxylon than E. viminalis and E. baxteri.

199 Figure 6.11: Proportion of substrate time spent by Melithreptus foraging from each substrate in four main eucalypts in the Scott area

Includes data from all individuals of each Melithreptus species in both seasons.

0.8

0.7 e m i 0.6 t e at r 0.5 bark flower subst 0.4 foliage on of

i 0.3 hawk t

opor 0.2 Pr 0.1

0 E. fasciculosa E. leucoxylon E. viminalis E. baxteri Plant species

6.4 Discussion

6.4.1 The small Melithreptus guild

6.4.1.1 Feeding behaviour There was no evidence that M. brevirostris and M. lunatus, when feeding in the same areas at the same time, partitioned resources by one species foraging more from foliage and the other more from bark, as appeared likely following a review of the literature (Section 1.5.4). The ability to distinguish M. lunatus females and males in the behavioural results assisted in making this assertion. The small Melithreptus guild, yet again, appeared to act as a continuum, with male M. lunatus feeding from various substrates proportionally closer to M. brevirostris than female M. lunatus in every case in each season except for hawking, which was rarely used, and for feeding from bark in the non-breeding season, in which M. brevirostris still fell between female M. lunatus and male M. lunatus. While there were no statistical effects supporting this, such a trend was predicted from the results of Chapter 3. Further, all species/sexes changed the proportion of time spent feeding from bark and flowers in relation to season in the same directions, with no statistical interaction of species/sex and season.

200

The use of plant species provided the only evidence of partitioning between M. brevirostris and M. lunatus. Melithreptus brevirostris appeared to use E. fasciculosa more than M. lunatus (both sexes) during the non-breeding season (not supported statistically) and M. lunatus (both sexes) used E. viminalis more than M. brevirostris in both seasons. One other study suggested that M. brevirostris and M. lunatus were most different in their use of plant species, with E. viminalis also being used more by M. lunatus in that study (Ford et al. 1986). The importance of E. viminalis to M. lunatus is not easy to explain. In the breeding season, very little time was spent by M. lunatus foraging in E. viminalis, with total substrate time of about 2.6 minutes, 96% of which was spent gleaning foliage. In the non-breeding season, 21.7 minutes of substrate time was recorded for M. lunatus in E. viminalis. During this time there was an even spread of proportion of time spent feeding from foliage, bark and flowers; 32.5%, 38.3% and 29.5% respectively. Perhaps E. viminalis is important to M. lunatus not because it is E. viminalis, but because of where it occurs. Eucalyptus viminalis occurs on the most locally productive soils, often in restricted areas and along drainage lines. The most productive soils have been shown to support the richest and most abundant arthropod faunas, including psyllids (Recher et al. 1996). Taking this one step further, the differential use of productive soils may have provided the only evidence of partitioning between M. brevirostris and M. lunatus. A preference for more productive soils by M. lunatus is also reflected by the more limited geographical distribution of M. lunatus compared with M. brevirostris. One further possibility for the importance of E. viminalis is that it usually grows in association with or nearby to other gum eucalypt species, particularly E. leucoxylon (Armstrong et al. 2003). This may be of importance in providing free space, within a landscape of aggressive honeyeaters, at times when E. leucoxylon is flowering, allowing M. lunatus to coexist in close proximity to aggressive honeyeater territories without serious risk to the individual. Such areas may also be important for staging raids on aggressive honeyeater territories, as they may allow information to be gained on when aggressive honeyeaters leave their territories.

The large proportion of time spent foraging by Melithreptus may be due, in part, to Melithreptus foraging less from flowers than P. novaehollandiae. Flowers provided the most predictable foraging substrate for each of the honeyeater species studied here. The large proportion of time spent foraging by Melithreptus also provides support for them

201 foraging from diffuse resources, as was suggested by the results of Chapter 5. Such resources may be spread so that each foraging action acquires only a small reward, or they may be spread so that foraging actions that provide a good reward are separated spatially (and therefore temporally as they require large search effort). Perhaps a combination of both is likely given the distribution of foraging times on various substrates, with many quick foraging actions presumably providing (at least occasional) small rewards and fewer, long foraging actions perhaps providing larger rewards. Presumably the longer foraging actions on various substrates did represent particularly successful foraging actions, but interactions with resource quality and handling efficiency are also likely, preventing any strong conclusions being drawn other than that flowers provided the most predictable foraging substrate and that Melithreptus generally foraged from poor quality resources.

6.4.1.2 Notes on breeding, social behaviour and roosts The aggression data suggests that male M. lunatus are predominantly responsible for defence of breeding areas. That males are mostly responsible for defending a breeding area has been reported for other honeyeater species (Paton 1979; Franklin et al. 1995; Oliver 1998b; Clarke and Clarke 1999; 2000). No male M. lunatus were confirmed incubating nests. There is good evidence of female only incubation from only two nests, one with a radio-tagged female and the other with a radio-tagged male. In both cases only two individuals were suspected of being involved with breeding, but the ‘partner’ bird was not colour-banded in either case. The radio-tagged male was seen to visit the nest to feed the (presumably) female bird sitting, remove faecal sacs and feed the female nearby to the nest but was never seen to sit on the nest. The radio-tagged female was often found on the nest, and was seen to be fed by another bird while on the nest, but during several occasions when radio signals confirmed the female was not near the nest, checking the nest area found no birds in attendance. It is possible that at such times the other bird was not sighted, but they were certainly not on the nest. Again, that females are mostly responsible for incubation has been reported for other honeyeater species (Paton 1979; Franklin et al. 1995; Oliver 1998b; Clarke and Clarke 1999; 2000). Observations of both radio-tagged individuals and non radio-tagged individuals suggest that at least two adult birds attended nestlings and fledglings. Thus, responsibility for feeding of nestlings and fledglings is likely to fall to both parents in Melithreptus, as has

202 been reported in a variety of other honeyeater species (Paton 1979; Franklin et al. 1995; Oliver 1998b; Clarke and Clarke 1999; 2000).

There is some evidence that M. lunatus exhibits a socially monogamous mating system. Two pairs of M. lunatus were known quite well on the northern boundary of the Scott area. One pair (RMRG and RMRY) was first caught in November 2000. Male RMRG was radio-tracked during July 2001 during which it was often found with female RMRY. The two birds were sighted together in August and September 2002 and during December 2003, each time within the area defined by RMRG’s home range during the radio-tracking period in 2001. The first and last records of these two individuals were taken of them together in the same area. However, female RMRY was never sighted in the non-breeding season. Another pair, RMGY and RMGW, were first caught in July 2001. The female RMGW was radio-tagged at that time and was engaged in nest building. The two were also seen together during December 2001, August 2002 and April 2003, each time within the home range defined during the radio-tracking period. There are records of both birds within the home range in both seasons. This pair nested together again in August 2002 during which time I suspect they fledged male M. lunatus RMYN, who was first caught as a 1st year adult in December 2002 within the home range of RMGY and RMGW. In April 2003, all three birds (RMGY, RMGW and RMYN) were seen together on two occasions. The last record of RMGW was in April 2003. RMGY was seen again in December 2003 with RMYN (in the same area) feeding dependent young. This last record indicates that male M. lunatus may remain on their parental breeding territory even when sexually mature. Another possible case of this was outlined in Section 6.3.1 regarding male M. lunatus RMYY. A socially monogamous mating system in which the male and female do not spend the non- breeding season together has also been reported in P. pyrrhoptera (Clarke and Clarke 1999; 2000; Foster 2001) and P. novaehollandiae (Paton 1979).

Melithreptus lunatus appear to have stable roosts, although at no time was I able to confirm that members of a pair (or group) roost together. One male M. lunatus radio- tagged twice was found roosting in the same grove of juvenile E. leucoxylon in February 2002 and November 2003. The grove was about twenty square metres in area and radio-signals were narrowed to an area of about four juvenile E. leucoxylon (~ 2m2). The trees were about four metres high but at no time was the M. lunatus sighted.

203 However, within the radio-tracking period in February 2002, this bird also roosted once (in a revegetated E. leucoxylon) about 2km south of its other, stable roost. Most other birds had consistent roosts during the radio-tracking periods. On the two occasions the roost was checked, the radio-tagged male partner of a breeding pair at Kaiser Stuhl roosted about 130 metres from the nest tree, but in the same tree on both occasions. Melithreptus lunatus appear to use their stealth abilities when approaching a roost as no birds were ever seen entering or leaving a roosting area, only radio-signals confirmed their presence.

The social organisation of M. brevirostris groups is less well known. At least two flocks from the northern Scott area were known to some extent. One contained RMRR, RMRY and RMRW, and later RMYN and RMWR, but included a number of other birds (known and not). I suspect there were alliances within this group based on what seemed unlikely association rates if there was a random chance to the order in which colour- bands were found within the flock. This may have been young birds remaining (closely) with parents for some time after reaching adulthood, perhaps learning from them. The best example of this is the very high association of RMRR and RMYN over a relatively short period of time compared with other known association lengths for RMRR (see Table 5.13). All groups of M. brevirostris found with nests appeared to share the incubating between a number of group members. The breeding behaviour of M. brevirostris groups was, to put it mildly, quite confusing, although this was perhaps partly due to my focus on one bird within the group and not on the nests. Some M. brevirostris associated with nesting groups made numerous visits to nest trees over several days and then did not go near the nest again, others appeared to visit two nests during the tracking period. One individual from a nesting group at Kaiser Stuhl spent nearly all of its time in a nest tree, emerging only occasionally.

Melithreptus brevirostris flocks appear to have stable roosting sites, with all flocks seen to roost within about 50 metres of previous roosts at any time. One flock consistently roosted on the same twigs near the top of an E. baxteri during one radio-tracking period. These twigs and tree were remarkable in absolutely no other detectable way. The roosting behaviour of M. brevirostris noted by Noske (1983) in which, ‘birds arrived at the intended roost site quickly, but after a short struggle, sometimes dismantled and flew to other trees or rested in nearby branches before attempting to assemble again at

204 the site’ occurred on some occasions, but I had the impression this was due to my presence. Once I had established the location of a roosting site, carefully approaching the area at other times on dusk generally saw the birds approach slowly in small groups, often feeding in the local area, before assembling quietly at the roost. Leaving in the morning was almost the reverse. Melithreptus brevirostris did not quickly leave the stringybark areas in which they roosted, but generally moved in a straightish line (foraging as they went) towards the areas of E. leucoxylon and/or E. fasciculosa in which they spent most of the day foraging.

6.4.1.3 Aggression Melithreptus brevirostris and female M. lunatus likely spend less time in aggression than other honeyeater species. The lowest from other studies summarised by Oliver (2001) was 0.3% for two species, Acanthorhynchus tenuirostris and Meliphaga lewinii (Lewin’s Honeyeater) (McFarland 1986a). This is greater than the 0.2% recorded for M. brevirostris and close to the 0.4% recorded for female M. lunatus. Male M. lunatus were involved in more aggression than M. brevirostris during both seasons. The 1.3% of time spent in aggression recorded for male M. lunatus put them close to the peak in distribution of time spent in aggression for the 19 studies on 14 species of honeyeater summarised by Oliver (2001). Thus, M. brevirostris spent less of their time in aggression than any other honeyeater species for which data are available, female M. lunatus were close to this value and male M. lunatus spent a similar proportion of time in aggression to those studies for which data are available.

Of the 29 aggressive acts by M. lunatus against other individuals during the breeding season, 22 (76%) were carried out by males and males chased other individuals 6.3 times an hour during the breeding season as opposed to no records for females during time budgeting in the breeding season. This result is an important piece of evidence supporting the contention that, at least in part, the differences in sexual morphology of M. brevirostris (apparently sexually monomorphic) and M. lunatus (sexually dimorphic) are related to the roles of the sexes in breeding (Chapter 3). Male M. lunatus are primarily responsible for defending the breeding territory, while female M. lunatus are primarily responsible for nest building and incubation. This situation is likely to lead to selection for larger males and smaller females. While little information is available on nest building, it appears likely that M. brevirostris sexes spend similar amounts of time

205 incubating, with other group members also assisting (this study, Noske 1983). The almost complete lack of aggression towards others displayed by M. brevirostris has not been commented on by previous authors, although McFarland and Ford (1991) do state that Melithreptus are not strongly aggressive.

While Melithreptus generally spent less time in aggression than other honeyeaters, the consequences of the small amount of aggression may still be enough to exclude Melithreptus from the best quality resources being defended by aggressive species. It seems unlikely that Melithreptus would choose not to forage on resources within their home range that are being defended, if those resources were not being defended (i.e. in the absence of territorial honeyeaters). This suggests that Melithreptus may spend less time in aggression, due to good knowledge of aggression levels within their home range and perhaps coupled with their use of stealth and swamping, allowing them to minimise their risk of attack while foraging.

6.4.2 Comparisons with the literature and P. novaehollandiae This study confirmed the established feeding behaviour of Melithreptus as eucalypt canopy specialists (e.g. Keast 1968a; Recher et al. 1985; Ford et al. 1986; Higgins et al. 2001). At all sites, Melithreptus were recorded most often in eucalypts, in which they gleaned from foliage and bark, probed bark and foliage and took nectar from flowers. Hawking was used rarely. Previous results from community studies in which it has been suggested that either M. brevirostris or M. lunatus forage more from foliage or bark may result from the studies having a spatial scale too large to directly investigate the two species behaviour in sympatry. The results obtained here for proportion of time spent on different substrates within different plant species lends good support to this argument. Melithreptus only fed from bark and foliage in equal proportions from E. leucoxylon and E. viminalis, whereas when feeding from E. fasciculosa Melithreptus fed from foliage much more than from bark and when feeding from stringybark, Melithreptus fed much more from bark than from foliage. Thus the results of large scale studies that did not focus on collecting data on M. brevirostris and M. lunatus in the same areas may actually be reflecting the different eucalypt species present or even perhaps different substrate productivities within the same species of eucalypt occurring in different areas (reflecting different arthropod communities).

206 In the introduction to this chapter the proportion of time spent foraging was summarised for studies in which all actions related to foraging were included in the proportion of time spent foraging. A comparison of the results with that summary suggests that Melithreptus fall close to the upper end of the range for proportion of time spent foraging. Melithreptus also fall at the low end of the range for proportion of time spent resting and in aggression. Were the methods used here in any way responsible for the results? The results for P. novaehollandiae suggest not. In this study, behaviour data on P. novaehollandiae were collected in the Melithreptus non-breeding season (January to July) and found that P. novaehollandiae spent 56% of their time foraging and 34% of their time resting, statistically less time foraging and more time resting than Melithreptus despite using identical methods and well within the range of recorded values for P. novaehollandiae (Paton 1979; 1980; 1985). After carefully considering information available in the literature and the results for P. novaehollandiae obtained here, the conclusion is clear: based on the data collected, Melithreptus in the Mt Lofty Ranges are in the very upper range recorded for other honeyeaters for proportion of time spent foraging and in the lower range for proportion of time spent resting. This result is consistent with Melithreptus exploiting either diffuse or widely separated food resources. In either case, such food resources could be considered poor quality for honeyeaters.

6.4.3 Melithreptus foraging behaviour If Melithreptus are adapted to foraging from poor quality resources, their large but apparently stable home range is probably a result of needing a large area to contain enough resources to support the flock (in the case of M. brevirostris) or the group (individual, pair or small group in the case of M. lunatus). A good knowledge of the best areas for foraging is likely to assist Melithreptus in using poor quality resources, and hence it would be advantageous for individuals to have stable home ranges and core areas. Many of the foraging resources used by Melithreptus are not obviously visible (at least to a researcher), suggesting that learning may play an important role in Melithreptus ecology. This may, at least in part, be a cause of the relatively large group sizes recorded for Melithreptus, especially M. brevirostris which undoubtedly uses the areas with poorest soils and probably correspondingly poor resources.

207 The ectethmoid-mandibular articulation (EMA, Bock and Morioka 1971) may be the enabling aspect of Melithreptus ecology which gives them access to a greater proportion of the poor quality resources within their relatively large home range. The EMA must have evolved for its adaptive value, and as it involves the feeding apparatus (beak, skull and associated musculature) the adaptation is likely to be related to feeding. Melithreptus appear to have in common their use of a relatively large home range, group size related to home range size and large proportion of time spent foraging. Without the EMA, these aspects of their ecology may not enable Melithreptus to fill the niche they have, as they already move over large areas and spend a lot of time foraging. Hence the suggestion that the EMA is the enabling feature of the Melithreptus niche. One other species of honeyeater has a precursor to the EMA; M. melanocephala (Bock and Morioka 1971). This is also a honeyeater with stable home range, complex social behaviour and similar foraging behaviour to Melithreptus (Dow 1977). However, in the case of M. melanocephala home range is probably not as large (in terms of the hectares required per individual) with resources more predictable due to defence of resources through indiscriminate interspecific aggression (e.g. Dow 1977).

Given that the large home range is probably required to access an adequate supply of resources, the effects of fragmentation on Melithreptus are clarified further. It is possible that in most seasons, resources are adequate within a group’s fragmented home range. However, in seasons where resources are not adequate the group has no where to go to increase their foraging range. This may have been occurring when a number of Melithreptus were radio-tracked in feeding flocks outside their core areas (see Section 5.3.2). In each case these birds were feeding in stringybark (E. obliqua and/or E. baxteri) and were usually probing under bark. This suggests that M. brevirostris and M. lunatus should only have home ranges in parts of the Mt Lofty Ranges with a good mix of plant species, either within or nearby to their core areas, that increase the probability of resource availability throughout the year. Due to the larger weight and hence overall greater energy requirements of M. gularis, and its similar foraging regime to M. brevirostris and M. lunatus, M. gularis will experience food shortage more often than its smaller congenerics. It is unlikely that M. gularis is able to access any better or different resources through its foraging behaviour within the same habitats as its smaller congenerics. This suggests a larger home range size and larger core areas are likely for M. gularis, as supported by the one individual tracked here and the other members of

208 that individuals group. The implications of fragmented habitat for M. gularis in relation to feeding behaviour are again greater than for the small Melithreptus guild and the implications for all the Melithreptus are greater than for P. novaehollandiae.

209 Chapter 7 OVERALL CONCLUSIONS

7.1 The ecology of the small Melithreptus guild

7.1.1 Melithreptus brevirostris Melithreptus brevirostris were sexually monomorphic, or if differences between the sexes existed, they must have been very small, with considerable overlap.

Melithreptus brevirostris numbers were higher in areas with high numbers of P. novaehollandiae, suggesting a shared preference for resources with P. novaehollandiae. Phylidonyris novaehollandiae is an aggressive, widespread and abundant honeyeater in the Mt Lofty Ranges and is likely to compete with M. brevirostris at times of resource limitation. Based on the results of survey work and other studies, M. brevirostris are probably habitat generalists, whose abundance can be most closely modelled by resources, of which P. novaehollandiae served as a surrogate in this case.

The large overall home range of Melithreptus in both their non-breeding (mean 48 ha) and breeding seasons (12 ha) is probably a result of their reliance on poor quality resources. It is therefore not surprising that M. brevirostris abundance at a scale of one hectare is best modelled by resources, of which P. novaehollandiae were a surrogate. Within their large home range, M. brevirostris are likely to make use of temporal peaks in resources caused (most commonly) by flowering events which also attract P. novaehollandiae. At such times, M. brevirostris are likely to employ swamping as a strategy to access defended resources. This strategy was effective at allowing M. brevirostris individuals to access trees with a high level of standardised protection, although it also resulted in more frequent movement.

Melithreptus brevirostris generally have larger core areas than M. lunatus and did not appear to have any strong association with any particular plant species (such as Eucalyptus viminalis to M. lunatus), except that core areas were not recorded in areas of stringybark. Melithreptus brevirostris also move in larger groups than M. lunatus. These groups probably have a good knowledge of the resources within their core areas. The core areas used by M. brevirostris are likely to correspond to local peaks in soil

210 nutrients, but this idea needs further testing of the temporal stability of cores and particularly the spatial variation in soil nutrients. Melithreptus brevirostris, like M. lunatus, also forage from the full range of substrates available to them from the range of eucalypts present within their home range areas and spend most of their time doing this.

Data collected suggested very little movement of individuals between flocks. While no evidence was found, is seems unlikely that there would be no dispersal of M. brevirostris. Presumably quite young birds disperse from the parental flock to other flocks. Dispersal at a young age would allow a long period of learning from the new flock. Results of banding support the idea that there is little movement of adult birds out of their home range (see summary in Higgins et al. 2001).

7.1.2 Melithreptus lunatus Melithreptus lunatus were sexually dimorphic. Males were larger than females with differences greatest in weight and the lengths of exposed culmen and claw. Sexual dimorphism was probably the result of differences in breeding behaviour, as males were responsible for most territorial defence, and females were responsible for most incubation. Both parents assisted with feeding nestlings and fledglings. This breeding behaviour has been recorded for a number of other honeyeater species, all of which also exhibit sexual dimorphism.

Melithreptus lunatus numbers were higher in areas with E. viminalis and this was suggested to be based on the occurrence of E. viminalis in areas of high soil productivity. The Mt Lofty Ranges M. lunatus population may be limited by the availability of this plant species, or eucalypts on highly productive soils.

Melithreptus lunatus have larger home ranges than those recorded for other honeyeaters and their home range is larger in the non-breeding season than in the breeding season. Home range data of individuals confirmed the importance of E. viminalis with all individuals having E. viminalis present within their home range and usually close to core areas. Melithreptus lunatus were limited in their distribution and abundance at a local scale by the presence of P. novaehollandiae, a widespread and abundant honeyeater in the Mt Lofty Ranges. In areas dominated by P. novaehollandiae, M. lunatus may use stealth to access resources within aggressively defended territories.

211 However, M. lunatus was not able to access the most highly defended resources. The large areas of stringybark remaining in the Mt Lofty Ranges do not appear to provide habitat for M. lunatus, other than as occasional foraging areas supplementing core areas that do not occur in stringybark.

The M. lunatus sexes used the landscape differently. Particularly in the non-breeding season females had larger core areas, represented by kernel home range, than males. This was true both absolutely and as a proportion of their overall home range, represented by 100% minimum convex polygon. Females also consistently moved further than males over very short time frames. Males had more stable core areas, with a higher percent of males resighted within their core areas for periods greater than a year. Females were less likely to remain near breeding areas throughout the year than males, particularly in the non-breeding season. The fate of females not present in core areas during the non-breeding season was not clear, other than that they were more mobile than males and than themselves in the breeding season. Given that a proportion of them returned to the same breeding area from one year to the next, it is possible that they remain in contact with the breeding area during the non-breeding season.

When eucalypts within their home range flower, M. lunatus probably deals with interspecific aggression by foraging stealthily. Because of their small core areas M. lunatus may have a good knowledge of both levels of aggression and resources within core areas, increasing the effectiveness of a stealth strategy. Melithreptus lunatus foraged from the full range of substrates available to them, from the range of eucalypts present within their home range areas and they spent most of their time foraging. Movements outside of core areas were interpreted to occur due to resources within core areas being insufficient to meet requirements. During such movements, M. lunatus visited areas in which they were likely to have poor knowledge of levels of aggression and resources and did so in flocks, often of mixed species composition.

7.1.3 The comparative ecology of the small Melithreptus guild As a species, M. lunatus generally had smaller core areas than M. brevirostris. Melithreptus lunatus probably occur in smaller groups because their core areas occur in habitats that are generally restricted in nature in the Mt Lofty Ranges. The core areas used by M. brevirostris are likely to correspond to local peaks in soil nutrients but to be

212 in areas with lower productivity than M. lunatus core areas, although this idea requires further investigation.

Melithreptus brevirostris and M. lunatus sexes differed morphologically in ways that reflected differences in their movements and behaviour. The wing lengths of M. brevirostris and female M. lunatus were more similar to each other than they were to male M. lunatus. Melithreptus brevirostris and female M. lunatus also had the most similar home range size, core area size and short term (within a day) movements. Melithreptus brevirostris were more similar to male M. lunatus than female M. lunatus in a range of morphological attributes that were most likely to relate to foraging. A trend in foraging behaviour supported this idea, as M. brevirostris foraged from substrates in a more similar proportion to male M. lunatus than female M. lunatus.

Perhaps the most often cited difference between the ecology of M. brevirostris and M. lunatus was their use of different foraging substrates. However, this was almost certainly a case of M. brevirostris and M. lunatus foraging from the substrates on which resource production is greatest. In different areas and at different times of year, the substrates on which resource production is greatest are likely to vary (e.g. Paton 1980). In this investigation of the foraging behaviour of both species in the same areas, neither species foraged statistically more or less than the other from any substrate at any time of the year. Both species spent a large proportion of their time foraging, probably for poor quality resources that were predominantly available from on and under bark and on and between foliage. In general, there is probably not enough resources reliably available from any one substrate to allow specialisation (niche differentiation) to occur, hence both species use resources from wherever they are available.

While M. brevirostris and M. lunatus differed predominantly in group size coupled with home range size, and probably habitat reflecting soil productivity, the ultimate cause of these differences is likely to be evolutionary and can only be speculated on here. It appears likely that M. brevirostris evolved in drier environments than M. lunatus, areas in which group size may be an advantage in finding spatial peaks in resources, maintaining good knowledge of those peaks and accessing temporal peaks in resources through swamping. Presumably M. brevirostris in drier areas than the Mt Lofty Ranges use similar strategies to those employed in the Mt Lofty Ranges, but move over even

213 larger areas. In contrast, the other two Mt Lofty Ranges Melithreptus probably evolved in wetter areas of Australia. In these areas resources may have been more predictable, allowing females to retain the overwhelming proportion of responsibility in incubating, while males defended the breeding territory. At some point, M. brevirostris and M. lunatus have become sympatric throughout southeastern Australia. Their ability of M. brevirostris to use larger home ranges on less productive soils is probably an important aspect of their sympatry with M. lunatus despite overlapping in distribution at a local scale and overlapping in morphology and foraging behaviour.

7.2 Melithreptus ecology

The data collected in this study suggested that Melithreptus in the Mt Lofty Ranges were characterised by relatively large home range size with stable core areas, similar foraging behaviour and morphology, lack of aggression and (probably) complex social behaviour. The inclusion of M. gularis in this characterisation rests on a small but relatively sound base. Foraging was similar in that all the Melithreptus spent most of their time foraging from all substrates available within their home range, and predominantly from eucalypts. Aggression initiated by Melithreptus was mostly associated with breeding. Complex social behaviour certainly occurred in M. brevirostris, probably occurred in M. gularis, but was less apparent in M. lunatus.

Melithreptus have probably always relied on poor quality resources that are available in the Mt Lofty Ranges predominantly from the gum eucalypts. This reliance on poor quality resources required a large home range and a large proportion of time to be spent foraging. Within Melithreptus home range there are likely to be spatial and temporal peaks in productivity and therefore resource quality. Spatial peaks may be more stable and related to local peaks in soil productivity, supplying lerp, manna and honeydew due to correspondingly more abundant and diverse arthropod communities (this suggestion relies on the results of Recher et al. 1996). These hypothesised spatial peaks are likely to correspond to core areas of use by Melithreptus. Temporal peaks may at times correspond to the more stable spatial peaks, but also occur during flowering in other parts of their home range. Particularly at temporal peaks, Melithreptus are likely to face competition for resources with widespread and abundant honeyeaters which often aggressively defend foraging territories. Melithreptus are likely to be good at exploiting both spatial and temporal peaks within their home range. Their resident status and large

214 proportion of time spent foraging allows good knowledge of resources and levels of aggression. This knowledge coupled with their stealth and swamping strategies allows them access to moderately elevated peaks in resources across their home range. They are probably excluded from the highest peaks (best quality) of resources due to defence of such resources by aggressive interference competitors, although M. brevirostris are able to access better quality, defended resources than M. lunatus, but for a shorter time. In the past, M. gularis may also have used a swamping strategy to access better quality resources, but may be limited in attempts to do so now due to reduced population and group sizes. The flexible foraging behaviour of Melithreptus and their taking resources from all substrates and all plant species (particularly eucalypts) within their home range are also likely to be important factors in their success at exploiting diffuse resources. Another factor likely to be important in their success at exploiting generally poor quality resources within a stable home range is the ectethmoid-mandibular articulation. This probably allows them to crop a slightly greater proportion of the poor quality resources than other honeyeaters.

One issue not addressed here, but a pertinent question in relation to the decline of Melithreptus, is the effect of vegetation clearance, habitat fragmentation and associated changes to ecosystem processes on carbohydrate producing invertebrates. Given that Melithreptus appear to rely on poor quality resources any changes to populations of carbohydrate producing invertebrates are likely to play a role in the further decline of Melithreptus.

7.2.1 Melithreptus as competitors? Paton (1980) suggests that the Meliphagidae may have radiated along with the eucalypt- eating insects, eucalypts and other flowering plants rather than radiating into unoccupied niches as suggested by Keast (1976). Paton made the distinction primarily to highlight the importance of lerp, manna and honeydew to honeyeaters rather than the insects Keast suggested were important to some genera of honeyeaters, Melithreptus in particular. However, it also highlights an important question with regards the ecology and evolution of Melithreptus. Are the Melithreptus uniquely adapted to the niche characterised in the previous section, or is there a shared preference with other genera of honeyeaters for the poor quality resources Melithreptus appear to forage on? The best way to examine the question would be to consider the situation in which Melithreptus

215 are removed from the system. Would other honeyeaters then use the same resources as Melithreptus? While I can only speculate, it appears likely that other honeyeaters would use the resources, although for some of the poorer quality resources, there may need to be some time for a ‘package’ to build to a level where a honeyeater without an EMA can still access the resource. Thus, Melithreptus may be successful exploitative competitors as they are able to crop a slightly higher proportion of poor quality resources due to their EMA. If this situation is occurring, Melithreptus could be considered ‘efficient exploitative competitors’, a phrase that has been used to describe traplining species. Traplining is a method of foraging in which an individual harvests a renewable resource from isolated sites in a regular way. Originally described in Euglossine bees in Central America (Janzen 1971), traplining has subsequently been recorded mainly in some hummingbird species (e.g. Buskirk 1976; Gill 1988). While large aggressive species are usually efficient interference competitors, defending concentrated resources through territoriality (e.g. Ford and Paton 1977; Ford 1979; Paton 1979; Wykes 1985; McFarland 1986a; Collins and McNee 1991), traplining species are said to be efficient exploitative competitors, defending widely spaced resources through depleting them, rather than direct aggressive behaviour to other individuals (e.g. Buskirk 1976; Gill 1988). Perhaps to some extent Melithreptus can be thought of as traplining species within Australian honeyeater communities. Melithreptus move over relatively large areas, depleting the resources (either widely spaced or diffuse) as they move. In order to be exploitative competitors, the depletion process must serve to defend the core areas against intrusion by other honeyeaters and thus make core areas unattractive to other honeyeaters. Defence through depletion has been recorded for peripheral areas of the territories of Selasphorus rufus (Rufous Hummingbird) (Paton and Carpenter 1984). Perhaps the best way to test this theory would be reciprocal removal experiments, similar to the P. novaehollandiae removal experiment reported in Chapter 3.

Under a theory of Melithreptus as efficient exploitative competitors it may be possible to apply the label ‘territory’ to the core areas of Melithreptus home ranges. The core areas of some Melithreptus were spatially stable for up to several years, Melithreptus were aggressive in spending their time depleting resources and this perhaps made their territory unattractive to other individuals or groups who acted submissively by not entering the territory. Core areas, corresponding to more productive areas, may be

216 visited more frequently to maintain the level of resources across the home range at the same, low level. While there was undoubtedly spatial variation in productivity within their home ranges, each area may be visited in order to maintain a low level of resources across the area.

A further interesting possibility occurs under such a theory relating to the current decline in all Melithreptus, and M. gularis in particular. Melithreptus gularis are now possibly not ‘efficient exploitative competitors’. Their numbers may now be too low within any one group to maintain the effort of defending core areas through depletion of the resources it contains. This in turn may allow other honeyeaters to access those resources, in the same way as undefended resources within an aggressive honeyeater’s territory may be exploited by other species if it leaves the territory. Melithreptus gularis may find their core areas invaded by the most widespread and abundant honeyeaters removing the standing crop of slightly elevated levels of poor quality resources. Further, M. gularis are probably not able to utilise swamping as a technique to access defended resources due to their currently reduced groups sizes in the Mt Lofty Ranges.

7.3 Widespread and abundant nectarivores

The Mt Lofty Ranges population of P. novaehollandiae is likely to be elevated relative to the amount of remaining habitat in the region, and possibly even more so in Melithreptus habitat. In comparison to Melithreptus, P. novaehollandiae have smaller home ranges, smaller core areas within their home range, use better quality resources and their population within remaining Melithreptus habitat is probably increased due to the ‘improvement’ of such habitat by woody weeds. A theme that recurs in P. novaehollandiae studies is the maintenance by males of a breeding territory outside the breeding season. Males may move some distance from these areas to feed in other productive habitats (this study, Paton 1979; Paton 1980; Pyke and O'Connor 1993; McFarland 2002). If P. novaehollandiae create breeding territories in habitat ‘improved’ through invasion by woody weeds this is likely to increase P. novaehollandiae abundance in Melithreptus habitat. Gum woodlands which originally had a grassy understorey are now the most weed invaded habitats in the Mt Lofty Ranges (Armstrong et al. 2003). At times of resource limitation, P. novaehollandiae are likely to compete with Melithreptus through their aggressive defence of resources and their exploitation of resources previously relied on by Melithreptus. Given that Melithreptus

217 resources are apparently of poor quality to start with, Phylidonyris novaehollandiae need only spend a small amount of their time foraging from the same substrate (under bark, on foliage) to start depleting the resources within Melithreptus core areas.

While work here has focussed on P. novaehollandiae as a competitor to Melithreptus, Anthochaera carunculata and Manorina melanocephala are also likely to compete with Melithreptus but in different ways. Anthochaera carunculata is likely to impact Melithreptus in similar ways to P. novaehollandiae, although it is not known to defend breeding territories year round and probably follows more closely the richest sources of nectar, diluting its effect on Melithreptus compared to P. novaehollandiae. The problem of M. melanocephala is not as pressing for Melithreptus as Melithreptus does not appear to overlap in habitat use to any great extent. However, if woodlands continue to degrade throughout the Mt Lofty Ranges, with many small clearances creating more edges, M. melanocephala habitat may encroach more on that of Melithreptus. It may also be the case that roadside vegetation and other linear habitat nearby to larger stands of vegetation that is currently occupied by M. melanocephala may have been able to supplement current Melithreptus habitat allowing larger populations to survive within the larger stands. Manorina melanocephala populations within corridors and remnants may also disrupt any movement between groups by Melithreptus.

Despite their likely role in the decline of Melithreptus, widespread and abundant honeyeaters, particularly P. novaehollandiae, provide essential ecological services. These services may be even more important in the current landscape generally depleted of native pollinators. The widespread and abundant honeyeaters, and P. novaehollandiae in particular, are important in maintaining gene flow in many species of Australian bird pollinated plants (e.g. Paton and Ford 1977; Ford et al. 1979; Paton 1982a; Paton and Turner 1985; Paton 1986a; b; Vanstone and Paton 1988). Foliage foraging honeyeaters, which includes P. novaehollandiae, may also be important in maintaining tree health through consuming invertebrates from foliage and thus helping to prevent outbreaks of lerp forming psyllids (Clark 1964a).

Finally, the most widespread and abundant nectarivore of the region has been essentially ignored throughout this study. Apis mellifera (honeybee) occurs everywhere in the Mt Lofty Ranges (Paton 1996; Paton et al. 2004a), although is probably most

218 active during late spring through to early autumn (Paton 1979). The effect of A. mellifera on the Australian biota are complex and not well understood (Anderson 1989; Paton 1993; 1996). While A. mellifera probably provides a pollination service to some plant species that suffer reduced pollination services in a landscape depleted of native pollinators they also undoubtedly have negative effects on both other plant species and carbohydrate foraging animals (Paton 1993). If A. mellifera access the same resources as Melithreptus, their effect is likely to be similar to that documented by Paton (1979), ‘Apis mellifera clearly consume a high proportion of the nectar produced during summer, and their presence must reduce the number of honeyeaters that can be supported in an area. Honeyeaters compensated for the effect of insects on nectar resources by defending more flowers.’ However it seems unlikely that A. mellifera will be able to access carbohydrate resources predominantly under bark, on foliage and between foliage, probably reducing their impact on Melithreptus, at least in comparison to the more nectarivorous honeyeaters.

7.4 Conservation of Melithreptus in the Mt Lofty Ranges

7.4.1 Habitat management As has been suggested at various times throughout this study, the effect of woody weed invasion on Melithreptus is likely to manifest itself through local increase in P. novaehollandiae abundance. Interactions between P. novaehollandiae and Melithreptus have been dealt with in depth earlier in this thesis. This raises the prospect of woody weed control as a conservation option for Melithreptus. Weed control targeted at Melithreptus conservation should focus on blackberries in areas dominated by E. viminalis and olives, boneseed and broom in areas dominated by E. leucoxylon. Any areas selected for weed control for Melithreptus conservation should be in or adjacent to known Melithreptus home ranges.

In conjunction with the management of any wildlife population, monitoring should be carried out in both managed and control areas. Monitoring honeyeater species and abundance associated with weed management in these areas will also provide a test of the hypothesis that P. novaehollandiae are likely to be in higher numbers in gum woodlands with a woody weed layer (than healthy grassy woodlands) and, if the

219 previous hypothesis is demonstrated, provide a test for the theory that a reduction in P. novaehollandiae abundance will result in more frequent use of the area by Melithreptus.

One other issue is likely to face M. lunatus in the Mt Lofty Ranges due to its apparent reliance on areas containing E. viminalis. The current Mt Lofty Ranges Phascolarctos cinereus (Koala) population, a result of several introductions in the 1930’s, has expanded to a level at which it is now damaging certain preferred eucalypt species, specifically E. viminalis (Armstrong et al. 2003). The relationship between Koalas and certain preferred eucalypts is well established (e.g. Bryan 1995) and the potential for Koalas to cause widespread damage to the eucalypts in its preferred habitat is also well established (e.g. Possingham et al. 1996). If Koalas will impact any vertebrate (other than themselves) through overgrazing it is likely to be M. lunatus. Defoliation has been shown to change the avian community of eucalypt canopies with smaller species being disadvantaged in thinned canopies, probably through increased ability of large, aggressive species to detect the smaller species (Paton et al. 2002).

The relationship between Koalas and M. lunatus is currently the subject of a modelling exercise (M. Harper, Flinders University PhD student, pers. comm.). Irrespective of the results of modelling interactions between Koalas and M. lunatus, appropriately monitoring the Mt Lofty Ranges Koala population and Koala preferred habitat in anticipation of the management issue now present on Kangaroo Island (Armstrong et al. 2003), will be the first step in preventing any further decline in M. lunatus as a result of Koala overgrazing. Besides E. viminalis, E. leucoxylon is another preferred Koala food species, suggesting further impacts on the other Melithreptus if the Koala population continues to expand.

7.4.2 Habitat re-establishment Given the extensive clearance of native vegetation within the Mt Lofty Ranges, the even greater clearance of habitat apparently preferred by Melithreptus, the requirement of large home range sizes in Melithreptus and the even larger home range required by M. gularis, the provision of larger areas of woodland on good soils is the most obvious recovery technique available to reverse decline in Melithreptus. In the Mt Lofty Ranges Melithreptus habitat generally consists of gum woodlands, in particular E. leucoxylon and/or E. fasciculosa, with E. viminalis also occurring in suitable areas. These gum

220 species occurred on the most productive soils of the region but have been extensively cleared for agriculture. Acquiring large areas of productive land for re-establishing habitat will not be an easy task, but is essential not only to Melithreptus but to a large number of other declining woodland bird species. Perhaps obtaining useful sized parcels of such land for revegetation will require a different approach to the current practice of small patches on unproductive land that individual landholders are willing to give up from primary production. A suggestion that is more likely to fulfil the habitat requirements of Melithreptus is the revegetation of areas approaching in size entire farming properties (Paton 1999; 2000; Paton et al. 2004b).

Existing corridors of E. viminalis along creeklines amongst otherwise cleared land are unlikely to provide good habitat for M. lunatus core areas. Narrow areas often suffer extensive weed invasion and at times of flowering and/or manna production, M. lunatus may be forced from the area by large and aggressive territorial honeyeaters. However, targeting such areas for revegetation may improve the success for Melithreptus, as the areas are likely to support M. lunatus populations sooner than areas in which E. viminalis must also grow from juvenile stages.

Any new habitat provided for Melithreptus should be monitored for dominance by any one (or few) species, particularly those widespread and abundant honeyeaters in the region, P. novaehollandiae and Anthochaera carunculata, but also M. melanocephala. Minimising dominance by the widespread and abundant honeyeaters is probably best achieved by providing a range of eucalypt species, particularly E. leucoxylon, E. fasciculosa and E. viminalis. Melithreptus may be at a disadvantage in areas dominated by one eucalypt species, as during the flowering of that species, core areas may be ‘full’ of widespread and abundant honeyeater species. Melithreptus are also likely to benefit from a range of eucalypt species providing resources at different times of year, as are most honeyeaters.

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