Australian Field Ornithology 2016, 33, 187–197 http://dx.doi.org/10.20938/afo33187197

Field techniques in the study of Australian pigeons and doves

Andrew Peters1, 2*, Shane R. Raidal2 and David A. Roshier3

1Graham Centre for Agricultural Innovation, Wagga Wagga Agricultural Institute, Wagga Wagga NSW 2678, 2School of & Veterinary Sciences, Charles Sturt University, Wagga Wagga NSW 2678, Australia 3Australian Wildlife Conservancy, P.O. Box 8070, Subiaco East WA 6008, Australia *Corresponding author. Email: [email protected]

Abstract. Pigeons and doves (Family ) represent a significant component of Australia’s avifauna, possessing unusually diverse phenotypic and behavioural characteristics. The importance of many of them as ecosystem service providers and the emergence of new threats to them in Australia and the region warrant the development of standardised research methods such as effective and humane capture and collection of biological samples. We present here techniques, including novel mist-net set-ups that we trialled for the capture of Australian pigeons and doves. These were successful in 12 out of 14 in which attempts were made, including the arboreal Brown Cuckoo-Dove Macropygia amboinensis, Rose-crowned Fruit-Dove Ptilinopus regina and Torresian Imperial-Pigeon Ducula spilorrhoa, as well as both escarpment-dwelling rock-pigeons Petrophassa spp. Methods for the collection of biological samples are also presented.

Introduction 100% mortality in infected flocks of Rock Doves C. livia), emerged in Victoria (Department of Primary Industries Australo-Papua has a rich diversity of pigeons and doves Victoria 2011; Walker & Phalen 2011). For conservation, (Family Columbidae) with 59 of the 301 extant species animal production and human health reasons, there is a globally, of which 22 breed in mainland Australia (Frith need for a better understanding of the factors that facilitate 1982; Higgins & Davies 1996; Coates & Peckover 2001; the movement and transmission of disease by wildlife, both BirdLife International 2008). Phylogenetic studies over within and between wildlife populations, and to humans the last decade strongly support the Australasian region (Garamszegi & Moller 2007; Altizer et al. 2011). (Australo-Papua, Wallacea and the South Pacific) as a Pigeons and doves are of great international significance, shared biogeographic centre, along with South America, considering both the ecosystem services that various for the world’s pigeons and doves (Pereira et al. 2007; species provide and the alarming fact that almost a third of Gibb & Penny 2010; Jønsson et al. 2011). This evidence them (100 species) are threatened (BirdLife International supports a Late Cretaceous and Gondwanan origin for 2008). Although all but one Australian species are them, suggesting a deep biogeographic association considered by the IUCN as of Least Concern (the Partridge between Australasia and this avian lineage that may have Pigeon smithii is listed as Near Threatened), contributed to the current phenotypic and behavioural changes in distribution and abundance (often presumed to diversity of these in continental Australia. be caused by anthropogenic factors) have been recorded in Of the 22 species of pigeons and doves that breed in 15 other Australian species (Higgins & Davies 1996). This mainland Australia, most are confined to or have ranges is of concern as six Australian columbids are considered that extend into the tropics, and at least two move between excellent seed-dispersers for Australian rainforest Australia and (Higgins & Davies 1996; Coates (Cadow 1933; Crome 1975a; Healey 1992; Bhattacharyya & Peckover 2001). From a conservation and infectious 1994; Whittaker & Turner 1994; McConkey & Drake 2002; disease perspective, this is significant because future McConkey et al. 2004; Price 2004, 2006; Meehan et al. emerging disease hotspots due to zoonotic pathogens from 2005; Westcott et al. 2009) and many of the remainder both vector-borne and wildlife pathogens are expected to may perform previously unrecognised ecosystem functions be more concentrated in low-latitude countries (Jones et such as seed predation and nutrient linkage, especially al. 2008). Pigeons and humans have long been in contact where oligotrophic soils are found (Heine & Speir 1989; through domestication, and emerging infectious diseases Maron & Vila 2001; Croll et al. 2005; Sekercioglu 2006). in humans and wildlife are increasing worldwide alongside Investigation into the ecology of Australian columbids is an other forms of global change (Morens et al. 2004; Daszak important step toward their effective conservation. et al. 2007a,b; Jones et al. 2008). There is increasing evidence of the introduction of exotic pathogens into Live capture is important in the study of birds, especially Australia with the potential to impact on wild populations where mark–recapture, telemetry or haematological of columbids (Walker 2011). These include the protozoan investigation is required, and methods for live capture must Trichomonas gallinae, which has been responsible for comply with the high standards of animal welfare expected mass mortalities in several pigeon species in the Northern by Australian permitting authorities and the community Hemisphere and which is a significant obstacle to recovery (Farnsworth & Rosovsky 1993; Gaunt et al. 1999; of the endangered Mauritian Pink Pigeon Nesoenas Monamy & Gott 2001; Bangert 2005; Animal Research mayeri (Ostrand et al. 1995; Höfle et al. 2004; Bunbury et Review Panel & Department of Primary Industries NSW al. 2007; Gaspar da Silva et al. 2007). Recently a strain 2011). Few studies describe methods for the capture of of Avian Paramyxovirus (APMV-1, which is causing up to Australia’s endemic columbids (Crome 1975b; Price 188 Australian Field Ornithology A. Peters et al.

requires an innovative approach in field techniques. Here we describe a suite of techniques designed and trialled for the live capture and collection of biological samples from many of Australia’s unique pigeons and doves.

Methods

Species and sites Attempts to capture and sample individuals from 14 species of native pigeons and doves were made between August 2009 and October 2011 at 14 sites across northern and eastern Australia (Figure 1, Table 1). The ranged from open savannah dominated by Eucalyptus spp. to dense, tall, late-succession rainforest and mangrove forest. follows the BirdLife Australia Working List v. 1.2.

Call-playback Figure 1. Distribution of attempted capture sites in Responsiveness to call-playback was assessed for targeted Australia (see Table 1). species in an attempt to lure birds into a net or trap. Call recordings (Plowright et al. 2007) were played on constant repeat at maximum volume using a portable mp3 player 2006), in contrast with the capture of feral Domestic (iPod Nano, Apple Inc.) connected to a portable speaker Pigeons (DeMent et al. 1987; Clayton et al. 1999) or native (1.8 W, Moshi Bassburger, Lomis International). For each columbids in other regions (Curtis et al. 1983; Clout et al. species, the recorded call was played for 5 minutes when 1995), which differ markedly in their ecology from those birds were observed, with observers standing at least species of columbids in Australia. The unique phenotypic 20 m away from the speaker. Response was categorised and behavioural diversity of Australian pigeons and doves as either no obvious response (0), response without

Table 1. Capture sites of pigeons and doves in this study. AWC = Australian Wildlife Conservancy, NP = National Park.

Code Site Location Relevant habitats AT Private rural/bush property Millaa Millaa, Tropical rainforest Introduced pasture CH Private rural/bush property The Channon, New South Wales Subtropical rainforest Introduced pasture Garden CW Private bush property Cape Weymouth, Iron Range, Queensland Tropical sclerophyll woodland Mangrove DW Private urban property Lee Point, Darwin, Introduced pasture Garden FH Public nature reserve Fingal Head, New South Wales Littoral subtropical rainforest GG Public nature reserve Smith & Black Points, Garig Gunak Barlu NP, Tropical sclerophyll woodland Northern Territory Monsoon rainforest IR Island nature reserves Restoration Rock & Rocky Island, Iron Range NP, Littoral tropical rainforest Queensland Grassland KD Public nature reserve Western Arnhem escarpment, Kakadu NP, Sandstone outcrops Northern Territory Tropical woodlands LI Public nature reserve Low & Low Wooded Isles, Queensland Littoral tropical rainforest Mangrove MZ Private nature reserve AWC property, Paluma Range, Queensland Tropical sclerophyll woodland PG Private nature reserve AWC property, Calvert River, Northern Territory Tropical sclerophyll woodland Open woodland with ST Public nature reserve Sturt NP, New South Wales Xeric scrubland Riparian woodland VR Public nature reserve Victoria River escarpment, Gregory NP, Northern Sandstone escarpment Territory WW Private urban property Wagga Wagga, New South Wales Introduced pasture Garden Field techniques for studying Australian pigeons and doves 189

Figure 2. A. Parallel nets set on two 12-m-high carbon-fibre poles next to a fruiting Carpentaria Palm. B. 8-m-high carbon-fibre pole showing serial nets running in both directions. C. 8-m-high serial nets set beside a lake for the capture of Common Bronzewings. Photos: Andrew Peters approaching within 5 m of the playback device (e.g. head- the nets ran on the outside of the supporting guy ropes turning, flying past) (1), or response and approach to within (Figure 2B). This allowed a maximum net line length of 5 m of the device (2). The highest score (0–2) from up to 54 m, which could be elevated up to 8 m above ground three separate attempts on different individuals was used level. for the species’ response level. 6. U-shaped corral set-up: Four 1.75-m extendable Capture aluminium poles were used to hold a single 18-m-long net in a U-shape (Figure 3). The two rear poles for the corral Six different mist-net configurations were used, using nets were placed first, 6 m apart, and were each supported by of 16- or 30-mm square mesh and four or five shelves: three guy ropes attached to their tops. One of the front 1. Ground-level set-up: Two 1.75-m extendable aluminium poles was then placed 6 m directly in front of one of the rear poles were used to set nets up to 18 m in length at ground poles of the corral. The net was looped onto this pole and level (Low 1957). a twin-tailed guy rope was used to provide tension against the pull of the net. The net was then walked around the 2. Low-canopy set-up: Two 8-m black carbon-fibre poles, back of both of the rear poles (but inside their guy ropes) each with a flagpole-style rope running between pulleys at and forwards again to the fourth pole, which was placed the top and bottom of the pole, were used to elevate a net 6 m directly in front of the remaining rear pole. A twin- line up to 8 m above ground level (Peters & Raidal 2012). tailed guy rope was used to provide tension against the net

3. Mid-canopy set-up: Two 12-m black carbon-fibre poles, each with a flagpole-style rope running between pulleys at the top and bottom of the pole, were used to elevate a net line up to 12 m above ground level (Peters & Raidal 2012).

4. Parallel net set-up: This was similar to the mid-canopy set-up except that two nets (one above the other) were attached in parallel between the 12-m poles. Nylon thread was used to tie the bottom shelf of the upper net and the top shelf of the lower net together at 1-m intervals (Figure 2A).

5. Serial net set-up: Four 8-m black carbon-fibre poles were placed along a single extended net line. Loops from Figure 3. Illustration of a U-shaped corral net set-up. The the nets on both sides of the middle poles were attached focal point for call-playback devices, food or water baiting in alternating order (i.e. top loop for both nets, then lies ~1 m inside the entrance of the corral (black spot). subsequent loop for both nets etc.) while making sure that Sides are 6 m in length. 190 Australian Field Ornithology A. Peters et al.

Traps: A simple 1 m × 1 m × 1 m walk-in feed-baited trap with four sides and a top was constructed of aluminium mesh (1 cm × 1 cm). The mesh was spray-painted black, and a door 30 cm × 30 cm was cut into the bottom of one side. This door was hinged at the top and was held open by a nylon line, and was operated manually at a distance of >10 m.

A hoop-throw net was made using a rigid, closed 80-cm- diameter stainless-steel hoop (gauge 3 mm). A 120-cm- diameter circle of black nylon netting (mesh size 16 mm × 16 mm) was sewn on to the hoop at the edges, creating a shallow pocket. This was held while slowly approaching birds sitting on tracks at night (Figure 4), and was gently thrown over an individual bird.

Figure 4. Use of a hoop-throw net for the attempted capture of Spinifex Pigeons. Photo: Andrew Peters Collection of biological samples Blood was collected from all captured birds using methods previously described (Clark et al. 2009; Owen 2011). Sterile cotton-tipped applicators were used to collect material for analysis of infectious organisms from the choanal infundibulum, the oesophagus and crop, and the cloaca (proctodeum) (Figure 5). These produced samples of material present in and draining from the nasopharynx and sinuses; from the surface or the lumen of the upper gastrointestinal tract; and from the lower gastrointestinal tract, reproductive and urinary tracts and present in the Bursa of Fabricius or on the pericloacal surface.

Results

Three hundred and fifty-five individuals from twelve species of native columbids were successfully captured and sampled (Table 2). Total captures for each species ranged from one White-quilled Rock-Pigeon Petrophassa albipennis to 278 Torresian Imperial-Pigeons. The Geophaps plumifera and were targeted but not successfully captured.

Species capture notes Successful capture of pigeons and doves was invariably preceded by a period of several days of observation of the group or individual birds being targeted, and in all species repeated attempts to capture a group of birds led to that group becoming increasingly wary.

Figure 5. Collection of material on cotton-tipped applicators Brown Cuckoo-Dove Macropygia amboinensis. The from three sites on a . A. The choanae (arrow) arboreal Brown Cuckoo-Dove was usually responsive to and infundibulum are approached directly through the oral cavity. B. The crop and distal oesophagus (arrow) are its own call (either by call-playback or human whistle). approached by the oral cavity and proximal oesophagus Likewise, it was most often located in rainforest by call. (which lies behind the easily visualised glottis). C. An Successful capture involved identification of low (<8 m applicator is used to gently swab the inside surface of the tall) fruiting Tobacco Bush Solanum mauritianum, the cloaca, which is located underneath and anterior to the use of call-playback at this site and a low-canopy set-up tail. Photos: Andrew Peters supporting 18-m-long nets (density 210 Denier, mesh size 30 mm) (Figure 6A). Nets were set up encircling three sides of individual fruiting , separating these and the looped over this fourth pole. The objective of this set-up nearest contiguous rainforest fragment. was to allow walking birds to enter the corral, then to fly up and into the nets when disturbed from the side of the open Emerald Dove Chalcophaps indica. These were located entrance. To bring birds into the corral, an attractive focal either by call or by seeing them flush from the side of the point (e.g. call-playback device, dripping tap, seed bait) track as we drove along tracks through rainforest or wet was located inside near the middle of the front entrance of sclerophyll forest with dense undergrowth. They were the corral area. occasionally seen flying rapidly close to the ground, and Field techniques for studying Australian pigeons and doves 191

Table 2. Techniques used in the capture of Australian pigeons and doves in this study. Sites: See Figure 1 and Table 1. Techniques: Numbers of populations or sites at which a technique was attempted are shown in parentheses. Call response: 0 = no response; 1 = response without approaching playback device (e.g head-turning, flying past); 2 = approaching within 5 m of playback device. Net density: Values are given in denier (D) for braided nylon filament. Mesh: Length of one side of a square cell of the mesh is given.

Species Sites Attempted Successful Number Call Net density Mesh techniques techniques of birds response (D) (mm) captured Brown Cuckoo-Dove AT Low canopy (2) Low canopy (1) 4 2 210 30 Macropygia amboinensis Emerald Dove CH, GG Ground (2) Ground (2) 4 2 110, 210 30 Chalcophaps indica Common Bronzewing PG Serial net (1) Serial net (1) 3 1 210 30 chalcoptera U-shaped corral (2) WW Ground (1) Ground (1) 8 0 110, 210 30 Ocyphaps lophotes Spinifex Pigeon PG Ground (1) None 0 1 Geophaps plumifera Feed trap (1) Hoop-throw (1) Partridge Pigeon GG, KD U-shaped corral None 0 0 Geophaps smithii (2) MZ Ground (1) U-shaped corral 5 2 210 30 Geophaps scripta Feed trap (1) (2) U-shaped corral (2) White-quilled Rock-Pigeon VR Ground (1) Ground (1) 1 2 210 30 Petrophassa albipennis Chestnut-quilled Rock- KD Ground (1) Ground (1) 2 2 210 30 Pigeon U-shaped corral Petrophassa rufipennis (2) Diamond Dove ST Ground (1) Ground (1) 12 0 70, 110 16 Geopelia cuneata Peaceful Dove DW, GG, Ground (4) Ground (3) 12 0 70, 110 16 Geopelia striata MZ, PG Low canopy (3) Low canopy (1) Bar-shouldered Dove KD, DW, Ground (1) Low canopy (6) 20 2 110, 210 30 Geopelia humeralis FH, GG, Low canopy (6) LI, IR Rose-crowned Fruit-Dove GG, CW Low canopy (3) Low canopy (3) 6 2 210 30 Ptilinopus regina Torresian Imperial-Pigeon DW, LI, Low canopy (3) Low canopy (2) 278 1 210 30 Ducula spilorrhoa PG, IR Mid canopy (1) Mid canopy (1) Serial net (2) Serial net (2)

at some sites they were reasonably habituated to people. margin of freshwater lakes in the evening just after sunset On several occasions they responded to call-playback. A (Figure 2C), a well-recognised behaviour in this species. ground set-up was used to support nets 12–18 m in length (density 110 D, mesh 30 mm), which were placed in narrow Crested Pigeon Ocyphaps lophotes. The most successful native columbid in the exploitation of anthropogenic open areas, between vegetation, that were being used as a change in south-eastern Australia (Mulhall & Lill 2011), the flyway. Alternatively, call-playback was used in vegetation Crested Pigeon was common in rural and urban areas, at immediately behind nets to attract calling birds. times very habituated to humans. Where it was regularly Common Bronzewing Phaps chalcoptera. This found feeding on the ground in the morning or evening, a widespread species was deceptively hard to catch, being ground set-up was used with 12–18-m-long nets (density 110 or 210 D, mesh 30 mm). This set-up was best placed typically wary. Common Bronzewings were commonly a short distance (several metres) from a regular food or seen in suitable woodland habitat, especially along water source in order to catch birds either flying down to roads and tracks in the early morning or late afternoon. the site or, more commonly, to catch birds flying up away Although they occasionally responded to call-playback, from the attraction upon disturbance. No response was they did not typically approach the source of the call low elicited with call-playback in this species. or close enough to permit capture. Instead, a low-canopy serial net set-up supporting three 18-m nets (density 210 Spinifex Pigeon Geophaps plumifera. Groups of these D, mesh 30 mm) was used to capture birds flying to the birds were observed associated with spinifex Triodia along 192 Australian Field Ornithology A. Peters et al.

Figure 6. A. Serial 8-m-high net set-up for the capture of Brown Cuckoo-Doves beside a fruiting Tobacco Bush. B. Ground net set-up on top of a narrow sandstone ridge for the capture of White-quilled Rock-Pigeons. Photo: Andrew Peters sandstone creeks in the south-western Gulf of Carpentaria Squatter Pigeon Geophaps scripta. Squatter Pigeons country. They showed little response to call-playback and typically moved in small groups as they fed on the ground did not approach a seed-baited walk-in trap. At night, in the morning and afternoon. They were observed to return they rested on open tracks and sat quietly if approached regularly to the same area, and were found relatively easily as close as 2 m by vehicle. A hoop-throw net was used along roads and tracks in suitable open woodland habitat. to capture two birds, but on both occasions the hoop They appeared habituated to human presence around bounced momentarily upon landing over the bird and the homesteads. Almost invariably, they responded to call- playback, rapidly approaching the source of the call. Once bird escaped. We consider this technique very likely to be birds were located, a U-shaped corral set-up was deployed successful with some slight modifications. using an 18-m net (density 210 D, mesh 30 mm) with the Partridge Pigeon Geophaps smithii. This species, though call-playback device located on the ground ~1 m inside the more wary, was very similar in behaviour to the Squatter entrance. Once the birds had entered the corral, they were Pigeon G. scripta, although it showed no response to call- flushed into the net by rapidly approaching them onthe open side of the corral. playback. A U-shaped corral set-up supporting 18-m-long nets (density 210 D, mesh 30 mm) was used around a White-quilled Rock-Pigeon Petrophassa albipennis. The dripping tap that a group of Partridge Pigeons was coming rocky escarpment habitat preferred by this wary species to each morning in the late dry season. An individual made capture challenging. Nevertheless, the species bird near the tap flew into this net upon disturbance, but appeared to respond quite reliably to call-playback. Its managed to escape. habit of flying low over ridges of rock also provided an Field techniques for studying Australian pigeons and doves 193

opportunity for net capture. The following capture set- in diverse habitats (from open woodland to vine forest up was attempted in the evening at a site where we and mangroves) across northern and eastern Australia. flushed White-quilled Rock-Pigeons whilst walking on the Capture was most successful using 12–18-m-long nets escarpment. A small depression (diameter ~20 m) was (density 110 or 210 D, mesh 30 mm) supported by a located between the rocky outcrops and a call-playback low-canopy set-up, despite the ground-feeding habits of device was placed towards its centre. A ground set-up this species. Calling Bar-shouldered Doves occasionally supporting 12–18-m-long nets (density 210 D, mesh responded to call-playback, and a playback device could 30 mm) was placed along the ridges of the rocky outcrops be located close to but on the opposite side of the net to surrounding the depression (Figure 6B). This was lure them in. Alternatively, early-morning or late-afternoon exceedingly difficult, and devices for securing guy ropes placement of net lines in open spaces between low trees to the rock crevices would have been advantageous. We where a number of Bar-shouldered Doves had been seen waited, hidden, on the outside of this set-up once call- was frequently successful. playback was commenced, after which it took almost 30 minutes to catch a single bird. This species appeared to Rose-crowned Fruit-Dove Ptilinopus regina. The Rose- become quite easily stressed with capture. crowned Fruit-Dove was most easily caught in areas of dry coastal rainforest or margins of mangrove forest, with nets Chestnut-quilled Rock-Pigeon Petrophassa rufipennis. placed in open spaces between trees where birds were Although similar in many ways to the White-quilled Rock- heard calling (which usually was the only way they could Pigeon, this species was generally less wary at sites be located). A low-canopy set-up was used, supporting where capture was attempted amongst its preferred 12–18-m-long nets (density 210 D, mesh 30 mm). Males habitat of rocky outcrops along the north-western Arnhem often responded to call-playback, and the placement of a escarpment. Chestnut-quilled Rock-Pigeons were located playback device in the branches of a on the opposite by walking amongst rocky outcrops in the late afternoon side of the net worked very well as a lure. Rose-crowned or early morning where they were observed walking about Fruit-Doves appeared to have regular flyways and, once feeding in small groups. They could also be located by these had been identified through careful observation, nets carefully observing the ridgelines of rocky outcrops where were placed to intercept birds, which appeared to seldom they would rest. They initially responded to call-playback, notice the obstacle in their path. and would fly low over the playback device from the top of Torresian Imperial-Pigeon Ducula spilorrhoa. With the rocky outcrops to rock ledges on the other side, although correct technique, this species could be caught in large they appeared to quickly become desensitised to the numbers at breeding colonies along the eastern coast. By playback. A ground set-up supporting 12–18-m-long nets contrast, at feeding sites across their range and at roosts (density 210 D, mesh 30 mm) was placed around an open along the northern and north-western Australian coasts, sandy area bordered by rocky outcrops, where the birds had Torresian Imperial-Pigeons remain challenging to catch been observed repeatedly looking for food. The net lines because of their arboreal lifestyle. Occasionally, they were ~1–2 m from the edge of the rocky outcrops, which appeared to respond to call-playback, though this behaviour the birds would swoop up towards upon being disturbed. was not reliable enough to facilitate capture. These are When birds moved into the feeding area, it was necessary large and strong birds with a breathtaking ability to avoid to wait until they approached within several metres of a net nets while flying fast. They were witnessed clipping the top line before walking steadily towards them to cause them to of a net after turning, somersaulting in mid air and then flush towards the rocky outcrop and into the net. Chestnut- flying on. Because of their compact body shape, relatively quilled Rock-Pigeons should be processed promptly, with large mass and short strong wings and legs, one of the experience and care, as they appeared easily stressed by greatest challenges in their capture was the use of net capture, like the White-quilled Rock-Pigeon. fibres of sufficient density to prevent tears and escapes. Diamond Dove Geopelia cuneata. This small dove was Nets of less than 210-D nylon resulted in approximately seen most reliably as it approached water sources in the a third of trapped birds escaping. On the eastern coast, afternoon, though it may be caught moving about looking Torresian Imperial-Pigeons typically form large colonies for food during the day. A ground set-up supporting nesting on offshore continental islands and coral cays (King 12-m-long nets (density 70 or 110 D, mesh 16 mm) was 1990). Nests are located in littoral rainforest or mangrove used in areas where these birds were common or on trees, in bushes or even on the ground, and chicks can approaches to watering sites. Although generally robust, often be caught easily by hand. Upon disturbance, adults the small size of this species necessitates careful handling usually leave the nest, a well-recorded behaviour (Crome and sample collection. 1975b), but they appeared to return quickly once the area was left, and the chicks appeared to be robust and to grow Peaceful Dove Geopelia striata. This abundant species and fledge successfully despite daily disturbance. Adults was easily seen feeding on the ground or was located by were captured in the evening as they returned from feeding its characteristic call. Capture was similar to that described on the coast to the island colony where nets were set up. for the Diamond Dove, with location of nets around feeding Usually the largest number was caught at last light, and and drinking sites (especially focal sites such as dripping processing was often conducted in darkness. Birds leaving taps) often being most successful. Call-playback was not colonies in the morning typically flew too high to be caught observed to elicit any response. Careful handling and blood using the technique described. Following observation of collection should be used on such a small bird, despite the regular flyways onto the islands, a low-canopy set-up with relative robustness. 18-m-long nets (density 210 D, mesh 30 mm) was placed across the birds’ usual path (Figure 7). Often a serial set- Bar-shouldered Dove Geopelia humeralis. Bar- up with three nets was used. Most birds saw the nets and shouldered Doves were seen, and heard, commonly avoided them, with only the occasional member of a flock 194 Australian Field Ornithology A. Peters et al.

Figure 7. Setting up serial 8-m-high nets for the capture of Torresian Imperial-Pigeons on the approach to an island breeding colony. Photo: Andrew Peters turning too late. Once birds hit the net, it was imperative to criticism for use where observations are intended to be secure them as quickly as possible as they rarely became non-disruptive (BirdLife Australia 2012). For the approved entangled and often ‘bounced’ their way out of the shelf. capture of live wild columbids, however, we observed this technique to be highly efficient and to therefore involve a At feeding sites on the mainland, it was necessary to minimum of disturbance to the target population beyond locate isolated fruiting trees in which Torresian Imperial- the disruption of capture itself. Differences were observed Pigeons were feeding (such as a Melville Island White in the response to call-playback between species (Table Beech australianum or Carpentarian Palm 2). This may have been a result of differences in population Carpentaria acuminata). Birds typically dropped down responsiveness to the call recordings used, which in itself from the canopy en route from one feeding tree to another. may be due to divergence of target populations from those Once a pathway used in this manner was identified, a of the recordings (Irwin 2000; Irwin et al. 2001). In those low- or mid-canopy (Figure 2A) set-up was deployed when feeding birds were not present (such as midday or pre- species where this was not the case, a typical response to dawn). This was used to support an 18-m-long net (density the available call recordings may not necessarily involve 210 D, mesh 30 mm) and at times a parallel net set-up was approaching the source. It is also possible that seasonal used. Nets were unfurled and a discrete observation point differences in response to calls, especially those relating taken up before feeding birds arrived in the early morning to breeding, may have been a factor in some species’ (which was most successful) or mid afternoon. unresponsiveness. It may be advantageous to make high-quality recordings in situ if call-playback is being relied upon for capture. It is quite likely that the use of All species shed few feathers during capture and call-playback would lead to sex and age bias in captured handling, with Bar-shouldered Doves the most likely in individuals in a number of species, especially where calls this study to lose a few feathers. Most species, with the elicit behaviour related to breeding or territory. This was exception of the two rock-pigeons and the Brown Cuckoo- evident in our capture of Rose-crowned Fruit-Doves, of Dove, were robust during capture and handling and which all four birds caught using call-playback were males. appeared unaffected on release. Two out of the three individual rock-pigeons trapped, banded and sampled We have described techniques for the attempted capture took a prolonged period to recover. This recovery involved of 14 of mainland Australia’s 22 native columbids. Those walking away when released and resting under a rock species unaccounted for include some of the continent’s ledge for a short period. more interesting birds, in the context of feeding and behavioural ecology and seasonal movements, such as the Flock Bronzewing Phaps histrionica and Topknot Discussion Pigeon Lopholaimus antarcticus. Methods for capture of the Flock Bronzewing have been developed elsewhere We developed several innovations for the capture of (Dostine 2009). The arboreal and often high-flying nature pigeons and doves in addition to the detailed observations of several species, including the Banded Fruit-Dove made on the capture of each species. Novel techniques Ptilinopus cinctus, Superb Fruit-Dove P. superbus and extending the usefulness of mist-nets were found to be Topknot Pigeon, rendered them impractically difficult for effective for several species, but the most critical factor in capture using the techniques described here. Because the successful capture of most individuals of seven species of the prominence of these species as rainforest seed- was the use of call-playback. Call-playback has received dispersers, however, their movement may be of particular Field techniques for studying Australian pigeons and doves 195

interest in determining seed dispersal kernels for many of Agriculture, Forestry and Fisheries, Australian Government) ornithochorous rainforest plants, and further work is for financial support. We particularly thank our field assistants needed to identify reliable methods for their live capture. including Dean Marks, Vincent Roustang, Charlène Crémoux, Ian Patterson, Jenny Peters, Steven Hodgson, Nicola Wunderlich, Collection of biological samples is essential for numerous Anne Koetz, Eridani Mulder, Dejan Stojanovic, Sharanne Raidal, techniques used by biologists, ecologists, veterinarians Rick Kilpatrick, Alex Mateer, and John Pritchard. This research and wildlife managers. We collected four samples from could not have been carried out without the support and goodwill of each bird captured, enabling molecular investigation and Traditional Owners, landholders, Queensland Parks and Wildlife analysis of the distribution, phylogenetics and movement of Service, National Parks and Wildlife Service, Northern Territory the infectious organisms found in columbids. This material Parks and Wildlife Service and staff, the can also be used to understand population structure in Low Isles Preservation Society and in particular the Australian the birds themselves through the use of methods such Wildlife Conservancy. Animal ethics approval was given for this work by the Charles Sturt University Animal Care and Ethics as simple sequence repeats (SSR). The collection of Committee (#09/046), banding permission was provided from the blood was found to produce no adverse clinical signs Australian Bird and Bat Banding Schemes (#1844/2), and state and was practical in all 12 Australian pigeons and doves faunal licensing research permits were obtained (NSW #S12882, captured here, as well as three species (White-headed Qld #WISP06043409 and #WITK06042709, NT #38819). Pigeon Columba leucomela, Leucosarcia Permission was also given to conduct this research in Kakadu melanoleuca and Wompoo Fruit-Dove Ptilinopus National Park. magnificus) in which blood was collected from captive . Cotton-tipped applicators were successfully used to collect choanal, crop and cloacal material in all captured References species. For small-bodied species such as the Diamond Altizer, S., Bartel, R. & Han, B.A. (2011). Animal migration and Dove and Peaceful Dove, human urethral swabs may be infectious disease risk. Science 331, 296–302. more appropriate for collection of choanal and cloacal Animal Research Review Panel & Department of Primary material. Because of the longer recovery observed in two Industries NSW (2011). Wildlife Surveys: Animal Review of the three individual rock-pigeons, we recommend that Panel Guideline 10. Available online: http://www.animalethics. for these species the duration of handling during sample org.au/policies-and-guidelines/wildlife-research (retrieved collection is kept to a minimum and that there is a safe site 1 June 2011). for recovery (e.g. a rock crevice) next to the release site. Bangert, R. (2005). The ethics of lethal methods. Frontiers in Ecology and the Environment 3, 241–242. Various pathogens have been identified as threats to Beichle, U. (1987). Lebensraum, Bestand und Nahrungsaufnahme wild populations of birds in Australia, such as Beak and der Zahntaube, Didunculus strigirostris. Journal of Ornithology Feather Disease virus in parrots (Department of the 128, 75–89. Environment and Heritage 2005) and highly pathogenic Bhattacharyya, B. (1994). Diversity of feeding adaptations in Avian Influenza in waterfowl (Olsen et al. 2006). Research certain columbid birds: A functional morphological approach. has also suggested that West Nile Virus, a pathogen of Journal of Biosciences 19, 415–427. significance to wild birds in North America, may not be a Bingham, J., Lunt, R.A., Green, D.J., Davies, K.R., Stevens, V. & threat to the group potentially most at risk in Australia, the Wong, F.Y.K. (2010). Experimental studies of the role of the corvids (Bingham et al. 2010). By contrast, the emergence little raven (Corvus mellori) in surveillance for West Nile virus in Australia. Australian Veterinary Journal 88, 204–210. of introduced pathogens such as Avian Paramyxovirus BirdLife Australia (2012). Ethical Birding Guidelines. Available or exotic strains of Trichomonas gallinae in Australian online: http://www.birdlife.org.au/documents/POL-Ethical- columbids is an unknown risk. Establishment of the current Birding-Guidelines.pdf (retrieved 4 March 2013). distribution and identity of infectious organisms in pigeons BirdLife International (2008). IUCN 2010. IUCN Red List of and doves will require live capture and the collection of Threatened Species. Version 2010.4. Available online: http:// biological samples as described here. Our validation of www.iucnredlist.org (retrieved 31 May 2011). standard avian sample collection techniques in many of Bunbury, N., Jones, C.G., Greenwood, A.G. & Bell, D.J. (2007). Australia’s columbids should facilitate planning of health Trichomonas gallinae in Mauritian columbids: Implications surveillance in these birds. for an endangered endemic. Journal of Wildlife Diseases 43, 399–407. Several unusual genera of columbids (e.g. Cryptophaps, Cadow, G. (1933). Magen und Darm der Fruchttauben. Journal of Gymnophaps, Goura, Didunculus, Trugon and Otidiphaps) Ornithology 81, 236–252. are found in the wider region of Australasia, especially in Clark, P., Boardman, W. & Raidal, S.R. (2009). Atlas of Avian Wallacea, New Guinea and the South Pacific, some of Haematology. Blackwell, London. which are likely to shed light on the origins and evolution of Clayton, D.H., Lee, P.L.M., Tompkins, D.M. & Brodie III, E.D. the Columbiformes. Many of these are rare, poorly studied (1999). Reciprocal natural selection on host-parasite and are threatened by anthropogenic landscape change phenotypes. American Naturalist 154, 261–270. Clout, M.N., Karl, B.J., Pierce, R.J. & Robertson, H.A. (1995). and hunting (Beichle 1987; King & Nijboer 1994; Waltert Breeding and survival of New Zealand Pigeons Hemiphaga et al. 2004). Live capture and the collection of biological novaeseelandiae. Ibis 137, 264–271. samples of these species using expanded and adapted Coates, B.J. & Peckover, W.S. (2001). Birds of New Guinea methods based on those described here is likely to be and the Bismarck Archipelago: A Photographic Guide. Dove important in determining their health status and ecology, Publications, Brisbane. and in facilitating their conservation. Croll, D.A., Maron, J.L., Estes, J.A., Danner, E.M. & Byrd, G.V. (2005). Introduced predators transform subarctic islands from grassland to tundra. Science 307, 1959–1961. Acknowledgements Crome, F.H.J. (1975a). The ecology of fruit pigeons in tropical We thank the Australian Bird Study Association and the northern Queensland. Australian Wildlife Research 2, Wildlife Exotic Disease Preparedness Program (Department 155–185. 196 Australian Field Ornithology A. Peters et al.

Crome, F.H.J. (1975b). Breeding, feeding and status of the Torres Jønsson, K.A., Irestedt, M., Bowie, R.C.K., Christidis, L. & Strait Pigeon at Low Isles, north-eastern Queensland. Emu Fjeldså, J. (2011). Systematics and biogeography of Indo- 75, 189–198. Pacific ground-doves. Molecular Phylogenetics and Evolution Curtis, P.D., Braun, C.E. & Ryder, R.A. (1983). Wing markers: 59, 538–543. Visibility, wear, and effects on survival of Band-tailed Pigeons. King, B.R. (1990). Distribution and status of the Torresian Imperial Journal of Field Ornithology 54, 381–386. Pigeon Ducula spilorrhoa in north-eastern Queensland - Daszak, P., Epstein, J.H., Kilpatrick, A.M., Aguirre, A.A., Karesh, Cooktown to Cape York. Emu 90, 248–253. W.B. & Cunningham, A.A. (2007a). Collaborative research King, C.E. & Nijboer, J. (1994). Conservation considerations for approaches to the role of wildlife in zoonotic disease crowned pigeons, Goura. Oryx 28, 22–30. emergence. Current Topics in Microbiology and Immunology Low, S.H. (1957). Banding with mist nets. Bird-Banding 28, 115–128. 315, 463–475. Maron, J.L. & Vila, M. (2001). When do herbivores affect Daszak, P., Jones, K., Levy, M., Gittleman, J., Patel, N., Mara, V., invasion? Evidence for the natural enemies and biotic Nakielny, S.F., Chan, J. & Labo, M.N. (2007b). Global trends resistance hypotheses. Oikos 95, 361–373. in emerging infectious diseases. American Journal of Tropical McConkey, K.R. & Drake, D.R. (2002). Extinct pigeons and Medicine and Hygiene 77, 284–285. declining bat populations: Are large seeds still being DeMent, S.H., Chisholm Jr, J.J., Eckhaus, M.A. & Strandberg, dispersed in the tropical Pacific? In: Levey, D.J., Silva, W. & J.D. (1987). Toxic lead exposure in the urban rock dove. Galetti, M. (Eds). Seed Dispersal and Frugivory: Ecology, Journal of Wildlife Diseases 23, 273–278. Evolution and Conservation, pp. 381–395. Centre for Department of Primary Industries Victoria (2011). Paramyxovirus Agriculture and Bioscience International, Wallingford., UK. (PPMV1) in Pigeons: Situation Update. Department of Primary McConkey, K.R., Meehan, H.J. & Drake, D.R. (2004). Seed Industries, Melbourne. Available online: http://dpi.vic.gov. dispersal by pacific pigeonsDucula ( pacifica) in , au/agriculture/pests-diseases-and-weeds/animal-diseases/ Western Polynesia. Emu 104, 369–376. pigeon-virus/situation-update (retrieved 5 November 2011). Meehan, H.J., McConkey, K.R. & Drake, D.R. (2005). Early fate Department of the Environment and Heritage (2005). Threat of Myristica hypargyraea seeds dispersed by Ducula pacifica Abatement Plan for Beak and Feather Disease Affecting in Tonga, Western Polynesia. Austral Ecology 30, 374–382. Endangered Psittacine Species. Department of the Monamy, V. & Gott, M. (2001). Practical and ethical considerations Environment & Heritage, Canberra. for students conducting ecological research involving wildlife. Dostine, P. (2009). The Ecology and Conservation of the Flock Austral Ecology 26, 293–300. Bronzewing Pigeon Phaps histrionica. PhD thesis. Australian Morens, D.M., Folkers, G.K. & Fauci, A.S. (2004). The challenge National University, Canberra. of emerging and re-emerging infectious diseases. Nature 430, Farnsworth, E.J. & Rosovsky, J. (1993). The ethics of ecological 242. field experimentation. Conservation Biology 7, 463–472. Mulhall, S. & Lill, A. (2011). What facilitates urban colonisation Frith, H.J. (1982). Pigeons and Doves of Australia. Rigby, Sydney. by Crested Pigeons Ocyphaps lophotes? Corella 35, 73–81. Olsen, B., Munster, V.J., Wallensten, A., Waldenstrom, J., Garamszegi, L.Z. & Moller, A.P. (2007). Prevalence of avian Osterhaus, A. & Fouchier, R.A.M. (2006). Global patterns of influenza and host ecology. Proceedings of the Royal Society influenza A virus in wild birds. Science 312, 384–388. B: Biological Sciences 274, 2003–2012. Ostrand, W.D., Bissonette, J.A. & Conover, M.R. (1995). Gaspar da Silva, D., Barton, E., Bunbury, N., Lunness, P., Bell, D.J. Trichomoniasis as a factor in mourning dove population & Tyler, K.M. (2007). Molecular identity and heterogeneity of decline in Fillmore, Utah. Journal of Wildlife Diseases 31, trichomonad parasites in a closed avian population. Infection, 87–89. Genetics and Evolution 7, 433–440. Owen, J.C. (2011). Collecting, processing, and storing avian Gaunt, A.S., Oring, L.W., Able, K.P., Anderson, D.W., Baptista, blood: A review. Journal of Field Ornithology 82, 339–354. L.F., Barlow, J.C. & Wingfield, J.C. (1999). Guidelines to Pereira, S.L., Johnson, K.P., Clayton, D.H. & Baker, A.J. (2007). the Use of Wild Birds in Research. Ornithological Council, Mitochondrial and nuclear DNA sequences support a Washington DC. Cretaceous origin of Columbiformes and a dispersal-driven Gibb, G.C. & Penny, D. (2010). Two aspects along the radiation in the Paleocene. Systematic Biology 56, 656–672. continuum of pigeon evolution: A South-Pacific radiation Peters, A. & Raidal, S.R. (2012). An adjustable, lightweight pole and the relationship of pigeons within Neoaves. Molecular system for the capture of birds using mist nets in the low to Phylogenetics and Evolution 56, 698–706. mid canopy. Corella 36, 90–96. Goodwin, D. (1967). Australian pigeons: Their affinities and Plowright, H., Buckingham, R. & Jackson, L. (2007). A Field Guide status. Emu 66, 319–336. to Australian Birdsong. CD 3 (Red-necked Stint to Cockatiel). Healey, C. (1992). Abundance, diet and roosting defecations of Bird Observers Club of Australia, Melbourne. the Torresian Imperial-pigeon Ducula spilorrhoa in Darwin. Price, O.F. (2004). Indirect evidence that frugivorous birds track Corella 16, 107–110. fluctuating fruit resources among rainforest patches in the Heine, J.C. & Speir, T.W. (1989). Ornithogenic soils of the Cape Northern Territory, Australia. Austral Ecology 29, 137–144. Bird Adelie penguin rookeries, Antarctica. Polar Biology 10, Price, O.F. (2006). Movements of frugivorous birds among 89–99. fragmented rainforests in the Northern Territory, Australia. Wildlife Research , 521–528. Higgins, P.J. & Davies, S.J.J.F. (Eds) (1996). Handbook of 33 Sekercioglu, C.H. (2006). Increasing awareness of avian Australian, New Zealand & Antarctic Birds, Volume 3: Snipe ecological function. Trends in Ecology & Evolution 21, to Pigeons. Oxford University Press, Melbourne. 464–471. Höfle, U., Gortazar, C., Ortiz, J.A., Knispel, B. & Kaleta, E.F. Walker, C. (2011). The effect of quarantine on the health of (2004). Outbreak of trichomoniasis in a woodpigeon (Columba imported pigeons and its ramifications for Australia and palumbus) wintering roost. European Journal of Wildlife Australian pigeon fanciers. In: Cross, G.M. (Ed.). Proceedings Research 50, 73–77. of the Association of Avian Veterinarians Australasian Irwin, D.E. (2000). Song variation in an avian ring species. Committee Conference, pp. 75–77. Association of Avian Evolution 54, 998–1010. Veterinarians Australasian Committee, Canberra. Irwin, D.E., Bensch, S. & Price, T.D. (2001). Speciation in a ring. Walker, C. & Phalen, D. (2011). The PMV outbreak in Victoria. Nature 409, 333–337. In: Cross, G.M. (Ed.). Proceedings of the Association of Jones, K.E., Patel, N.G., Levy, M.A., Storeygard, A., Balk, D., Avian Veterinarians Australasian Committee Conference, Gittleman, J.L. & Daszak, P. (2008). Global trends in emerging supplementary material. Association of Avian Veterinarians infectious diseases. Nature 451, 990–993. Australasian Committee, Canberra. Field techniques for studying Australian pigeons and doves 197

Waltert, M., Langkau, M., Maertens, M., Härtel, M., Erasmi, S. & Received 16 August 2013, accepted 9 May 2014, Mühlenberg, M. (2004). Predicting losses of bird species from published online 21 September 2016 deforestation in Central Sulawesi. In: Gerold, G., Fremery, M. & Guhardja, E. (Eds). Land Use, Nature and Conservation and the Stability of Rainforest Margins in Southeast , pp. 327–352. Springer-Verlag, Berlin. Westcott, D.A., Dennis, A.J., Bradford, M.G., Harrington, G.N. & Note added in proof. Taxonomy in this paper McKeown, A. (2009). Seed dispersal processes in Australia’s follows the BirdLife Australia Working List v. 1.2. Both tropical rainforests. In: Stork, N. & Turton, S.M. (Eds). Living subspecies of the Emerald Dove—Chalcophaps indica in a Dynamic Landscape, pp. 210–223. indica of northern Australia, and C. i. longirostris of Blackwell Publishing, Melbourne. eastern Australia—were recorded in this study (see Whittaker, R.J. & Turner, B.D. (1994). Dispersal, fruit utilization Table 2). In the BirdLife Australia Working List v.2, these and seed predation of Dysoxylum gaudichaudianum in early are treated as subspecies of the Brown-capped Emerald- successional rainforest, Krakatau, . Journal of Dove C. longirostris (Northern C. l. longirostris and Eastern Tropical Ecology 10, 167–181. C. l. rogersi).