Government of South Australian Arid Lands Natural Resources Management Board

May 2009

South Australian Arid Lands Natural Resources Management Board Kowari monitoring in Sturt’s Stony Desert, SA Reece Pedler DISCLAIMER The South Australian Arid Lands Natural Resources Management Board, and its employees do not warrant or make any representation regarding the use, or results of use of the information contained herein as to its correctness, accuracy, reliability, currency or otherwise. The South Australian Arid Lands Natural Resources Management Board and its employees expressly disclaim all liability or responsibility to any person using the information or advice.

© South Australian Arid Lands Natural Resources Management Board 2009

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INTRODUCTION

Monitoring of the Kowari (Dasycercus byrnei) population on has been ongoing over the last 9 years following early work in the far north of South Australia and south- west Queensland in the 1990’s. Two monitoring grids were established on Clifton Hills Station by Department for Environment and Heritage in areas that were thought to represent ideal habitat for the species with the aim of comparing numbers between different intensities of cattle grazing and monitoring Kowari numbers over time. The grids near Pandiburra Bore (Pandiburra Grid) and Gap Paddock (Walker’s Crossing Grid) each consist of 200 Elliot (aluminium box) traps which are spaced at 100 m intervals in five 4 km lines. The last time that a full trapping session was conducted on these grids was in March 2006.

Since this time, a survey of major Kowari populations in South Australia was carried out in Spring 2007 on neighbouring pastoral properties to determine the status of the Kowari during a prolonged period of drought. This survey failed to detect any Kowaris and it was feared that they may be absent from these areas. Some additional opportunistic trapping was subsequently carried out on the Walker’s Crossing Grid in Gap Paddock and around Blue Motor Car Dam on in late 2007 by Reece Pedler and John Read and found encouraging numbers of young Kowaris. The aim of the current trapping was to check on the numbers of Kowaris remaining in these areas by comparing the numbers trapped with earlier monitoring sessions and to assess attributes of habitat relevant to Kowaris. Revisiting the area also allowed some opportunistic trapping in an area to the south of the monitoring grids that appeared to represent appropriate habitat based on satellite imagery.

METHODS

Fieldwork was conducted by Peter Canty, Robert Brandle, Alex Clarke and Reece Pedler. The two permanent monitoring grids established in areas of open gibber at Pandiburra Bore and in Gap Paddock were opened simultaneously for 4 nights from 11th -15th May 2009. Each grid consists of an array of 200 metal box traps (Elliot Type 2) set in five 4 km lines of 40 traps with 100 m spacing between each trap. Grids covers a minimum area of 16 km2 as each line is separated by 1 km, but a total area of 26 km2 includes a 500 m buffer around the grid. Traps were set for four nights at each grid.

The Walker’s Crossing or ‘WAL’ Grid (in Gap Paddock) samples an area of gibber, swamp and dune in an area remote from a stock watering point with light levels of grazing. Pandiburra Paddock or ‘PAN’ Grid is positioned close to Pandiburra Bore, which has had historically moderate to high levels of grazing. The grids are approximately 30 km apart in the Koonchera Dune area on Clifton Hills Pastoral Lease (Figure 1).

Kowaris were trapped using Elliot traps baited with tuna oil soaked dog biscuits and peanut butter and rolled oats mixture. Each animal captured was given a unique temporary marking with a coloured paint combination on the tail, allowing animals recaptured within the same trapping session to be identified. Each animal captured was weighed, measured and released back at its point of capture.

Four established vegetation monitoring transects on PAN GRID and six on WAL GRID were resampled. Sampling involved 300 consecutive wheel-point measurements in vegetated areas of specific habitat types. Series of sand mounds on gibber, also sampled for vegetation cover, were monitored for signs of herbivore activity (tracks and scats) and burrowing activity by larger reptiles and mammals (burrows greater than a twenty cent coin in diameter).

In addition, sand mounds were scored for Kowari habitat value using the methodology developed by Canty and Brandle (2008), which takes into account various parameters of mound condition, including shape and profile, damage by cattle and other herbivores, surfaces scalded by wind and water, hard crust and cryptogam cover, live vegetation and litter cover, height of vegetation and diversity of perennial and annual grass species.

Additional opportunistic trap effort was carried out for Kowaris in areas that were identified as being suitable based on satellite imagery. Two traplines were set in Laundry Paddock, the first east of Rotten Swamp (100 traps over 10 km, opened for 2 nights, 15th and 16th May) and a second south of Gillan Gillan Waterhole (80 traps open for one night, 16th May). A line of 40 Elliot traps was also set along a sand dune in the same area following an observation of Ampurta (Dasycercus cristicauda) tracks.

Figure 1. Map of central area of Clifton Hills Station, showing locations of PAN and WAL monitoring grids and the location of opportunistic trap lines set in Laundry Paddock. RESULTS AND DISCUSSION

KOWARI MONITORING

PAN Grid A total of 35 new individual Kowaris were captured on PAN Grid, including 17 males and 18 females over the four nights. Nine of these animals were subsequently recaptured. The majority of the animals caught were young individuals which had not bred before, indicating that they were the result of a reasonably recent breeding event (most likely Spring 2008). Two of the animals caught were very young (only recently independent of their mothers) and were caught in close proximity to each other on the western edge of the grid (row E). The age of these animals indicates some additional recent breeding, most likely associated with a flush of vegetation growth following a summer rainfall event.

WAL Grid A total of 9 new individuals were captured on the WAL Grid, including 3 males and 6 females over the four nights and 7 of these animals were subsequently recaptured. Like the PAN Grid, these captures included several young individuals from a Spring 2008 breeding event.

Densities of Kowaris at WAL Grid were 0.35 per km2 and at PAN Grid 1.35 per km2 (sample area of 26 km2 includes 500m buffer around grid). For WAL Grid, this density is consistent with trapping results over the previous four sessions, but well below the highest densities recorded in the 2001 and 2002 trapping sessions. Interestingly, the density of Kowaris on the PAN grid is the highest recorded to date. The reason for this discrepancy is not understood. However the vegetation response from rainfall presumably received in November and December 2008 (and more recently) seemed slightly greater at the Pandieburra Grid. It is also possible that the proximity to the flood event in Goyder’s Lagoon may have provided more available prey to the population near Pandieburra Bore. Large quantities of of moths, diving beetles and other insects were noticed around fluorescent globes at the campsite near Koonchera Dune and it is thought that some of the unseen benefits from the flood may be local increases in these insects within some distance from the floodwaters. This increased food source for Kowaris may also benefit other small mammals which Kowaris prey on, including Kultarrs and Hopping Mice.

Table 1. Details comparison of capture rates and numbers of individuals at both grids over the last decade. The total number of captures is displayed, with the number excluding recaptures shown in brackets and the percentage trap success below.

Site Trap Effort – Captures (individuals captured) trap nights % trap success August October May August April March June March May 1999 2000 2001 2001 2002 2003 2003 2006 2009 WAL 200 x 4 = 800 39* 32 (30) 50 (37) 54# (42) 67 (36) 16 (11) 4 (4) 6(6) 16(9)** GRID 3.3% 3.6% 6.3 % 5.7% 8.4% 2% 0.5% 0.75% 2% PAN 200 x 4 = 800 - - 30 (25) - 29 (19) 4 (3) 6(4) 13(7) 44(35) GRID 3.8 % 3.6% 1% 0.75% 1.6% 5.5% * no grids established. WAL site trap effort 1200 trap nights (400 traps x 3 nights set in long lines) # 50m x 50m sub-grid within WAL GRID established. WAL site trap effort 940 trap nights (100 x 1 night + 380 x 3 nights) ** trap effort in WAL grid slightly less: 720 trap nights (20 traps on dune not set) OTHER SMALL MAMMAL SPECIES

As with previous trapping sessions, several other small mammal species were captured in Elliot traps and observed on the monitoring grids in spotlights or vehicle headlights. Comparable numbers of Kultarrs (Antechinomys laniger) and Fawn Hopping Mice (Notomys cervinus) were captured in the current trapping session (Table 2.). Similar numbers of Kultarrs were caught on the two grids (4 on WAL grid, 5 on PAN grid), however Fawn Hopping Mice were only captured on the PAN Grid during this session. The high capture rates and scent marking of traps by Kowaris (a predator of these smaller species) may influence their likelihood of capture and therefore not give a true reflection of their actual densities.

Table 2. Summary of all other small mammals that have been captured during the Kowari study since 1997. Figures from 1999 include the larger area and trapping effort resulting from the broad scale survey between Pandie Pandie and . The results from 2000 onwards relate to the Koonchera Dune area and pooled results from PAN and WAL grids. The total number of captures is displayed, with the percentage trap success below.

Trapping Session (trap effort) Species May Aug Apr Mar June Mar May 1997 1999 2000 2001 2001 2002 2003 2003 2006 2009 (500) (9600) (1400) (1600) (940) (1600) (1520) (1520) (1520) (1520) Kultarr 19 25 22 6 4 46 21 22 14 0 Antechinomys laniger (3.8%) (0.3%) (1.4%) (0.6%) (.3%) (3%) (1.3%) (1.37%) (0.92%) Stripe-faced Dunnart 5 1 2 0 0 0 0 0 0 0 Sminthopsis macroura (0.05%) (0.06%) (0.13%) Fat-tailed Dunnart 2 0 0 0 0 0 0 0 0 0 Sminthopsis crassicaudata (0.02%) Fawn Hopping-mouse 9 17 1 1 2 6 6 0 0 0 Notomys cervinus (0.09%) (1.2%) (0.06%) (0.07%) (0.13%) (0.37%) (0.39%) (Endangered SA) Sandy Inland Mouse 7 7 0 0 0 0 0 0 0 0 Pseudomys (0.07%) (0.5%) hermannsburgensis Desert Mouse 1 0 0 0 0 0 0 0 0 0 Pseudomys desertor (0.06%) Forrest’s Mouse 2 1 1 0 0 0 0 0 0 0 Leggadina forresti (0.02%) (0.07%) (0.06%) House Mouse 3 1 1 0 0 0 0 0 0 0 Mus musculus (introduced) (0.6%) (0.06%) (0.07%) Longhaired or Plague Rat 1 0 0 0 0 0 0 0 0 0 Rattus villosissimus (0.06%)

OPPORTUNISTIC TRAPPING IN LAUNDRY PADDOCK

This trapping resulted in the capture of one female Kowari, representing the first record of the species in this local area and the most southerly record of the species in recent years (approximately 70 km south-west of the monitoring grids). This area lies between the Builder’s Rest area on northern , where a Kowari was captured in 1997 and station staff have observed them over time. Although this is a useful and interesting record, the low capture rate of just one animal from 280 trap nights suggests that Kowari populations in this area are likely to be very low.

Opportunistic trapping targeted at Ampurtas in the dune area failed to capture any animals, despite fresh tracks being observed around several traps. Further trap effort in this area would be useful in confirming the species at this location. Ampurtas captured in this area would represent a new locality record for the species on the easterly margin of their known distribution.

VEGETATION AND HABITAT ASSESSMENTS

Sand mounds in the Gap Paddock (WAL Grid) area generally showed better condition in terms of structural attributes which are thought to be important for kowaris such as height and profile base on (Table 3 and 4). These mounds were also less impacted by cattle activity and showed fewer signs of erosion due to wind and water flow.

Wheel-point vegetation transect on sand mounds revealed that litter cover was similar in both areas (WAL 21.7%, Pan 21%). The substantially higher cryptogam cover at WAL (23.4% : 0.4%) reflects lower levels of sand mound surface disturbance which is corroborated by the average cattle track and scat counts per sand mound for the three sand mound transects at each site (WAL = 1.2 and 0.2; PAN = 38 and 2.5). Comparisons of average ephemeral and perennial plant cover at each grid indicates that the lightly grazed grid had almost double the cover of the regularly grazed grid (WAL = 25% and 46%: PAN = 13% and 26%). However when ephemeral plant cover in the swamp transects were compared this situation was reversed (WAL = 8%; PAN = 26%), indicating that there was likely to have been more significant recent rainfall at the regularly grazed PAN grid. The resultant higher plant productivity could account for a greater response in Kowari numbers at the PAN grid, however other factors such as proximity to a flooded Goyder’s Lagoon could have significantly boosted available Kowari Prey by an order of magnitude during the preceding breeding period.

Sand mounds areas where opportunistic trapping was carried out in Laundry Paddock were somewhat marginal in terms of what is regarded as optimum habitat for Kowaris. These mounds were all relatively small in diameter and did not achieve the height and shape considered optimal for Kowaris.

Table 3. Mound assessment locations and percentage of the 10 mounds scored at each location that met ideal criteria in terms conditions thought to be optimal for Kowaris using methods developed by Brandle and Canty (2007).

Location Zone Cover Profile Height Easting grasses Burrows Northing Grass sp Kowari sign Astrebla sp. Scald Cover Plant sp >10cm Hard Crust Cover Plant/Litter Cover Cryptogam Cover Trampling/Pugging Pedestalled perennial Robbo Tank - Gap Paddock 54 364756 7020434 40 10 70 60 0 40 60 10 30 0 50 0 0 WALGRID VT1 80 90 100 100 0 100 100 20 40 0 10 0 30 WALGRID VT2 40 40 100 100 10 30 40 20 10 0 0 0 50 WALGRID VT3 0 80 100 10 20 20 0 10 20 10 30 0 30 PANGRID VT2 70 10 40 30 50 80 0 20 0 40 30 0 60 PANGRID VT4 40 90 80 0 100 0 0 10 0 10 10 0 40 ROT00101 WP92 54 298737 6989251 10 20 100 80 0 0 10 10 10 40 0 0 30 ROT00201 WP404 54 307636 6984069 10 90 100 50 90 90 0 20 20 0 10 0 0 ROT00101 WP59 54 299688 6987400 40 30 90 70 0 20 0 10 10 0 0 0 0 ROT00101 WP59 54 299688 6987400 50 0 90 20 0 0 10 40 10 10 0 0 0 ROT00201 wp375 54 308820 6986459 30 0 100 90 50 50 0 100 20 10 0 0 10 ROT00101 wp15 54 302250 6990146 10 30 90 100 20 30 20 30 30 0 10 0 30

Table 4. Mound assessment locations and the general habitat description in a 50 m radius around the observer. Scores for Gibber Cover, Hard Depression, Sand Mound and Sand Spread Cover are based on 5 classes: 1 = <5%; 2 = 5-25%; 3 = 25-50%, 4 = 50-75%, 5 = >75%. Scores for Gibber Gibber Cover in preferred size range 5-50 mm are based on 4 classes 1= <50%, 2= 50-75%, 3 = 75-90%, 4= >90%. Trees and Shrubs are based on three cover classes 1 = 0%, 2 = <5%, 3 = >5%. Gibber Hard Cover in Sand Sand Trees or Gibber Drainage Location Zone Easting Northing preferred Mound Spread Shrubs Cover Depression size range Cover Cover >40cm Cover 5-50 mm Robbo Tank - Gap Paddock 54 364756 7020434 5 4 3 2 1 0 WALGRID VT1 4 4 3 3 2 2 WALGRID VT2 5 5 2 1 1 1 WALGRID VT3 5 3 2 3 1 0 PANGRID VT2 5 4 3 1 1 1 PANGRID VT4 5 3 5 1 1 2 ROT00101 WP92 54 298737 6989251 5 2 2 1 1 0 ROT00201 WP404 54 307636 6984069 5 4 5 2 1 1 ROT00101 WP59 54 299688 6987400 5 4 2 1 1 1 ROT00101 WP59 54 299688 6987400 5 3 3 1 1 2 ROT00201 wp375 54 308820 6986459 5 3 2 1 1 1 ROT00101 wp15 54 302250 6990146 5 4 1 1 1 1

CONCLUSIONS These results suggest that Kowari populations associated with the study grids are surviving the ongoing dry conditions, and at least for the Pandieburra Grid, are responding well to current conditions produced by patchy summer rainfall. Higher numbers of Kowaris captured on the Pandiburra Grid are likely to be the result of a combination of these local differences in rainfall and the nearby flooding of Goyder’s Lagoon which may increase the number of insects and small mammals that prey on insects available for Kowaris to feed on in the vicinity of the floodwaters.

The capture of a Kowari from the Rotten Swamp area on Clifton Hills provides a useful result for confirming our understanding of Kowaris distribution, although catching just one animal with the high amount of trap effort suggests that some Kowari populations may still be critically low.

Figure 1. An adult Kowari captured at PAN Grid during the monitoring session (photo Alex Clarke).

Figure 2. A Kowari ‘joey’ captured on the western side of the PAN trapping Grid. The age of this animal suggests an early 2009 breeding event, possibly in response to summer rainfall.

Figure 3. Assessing a sand mound for Kowari habitat attributes near Rotten Swamp, Laundry Paddock.

Figure 4. Sand mound habitat in the area in which a female Kowari was captured in Laundry Paddock, east of Rotten Swamp, near a tributary of the Tippipila Creek (in the background).

ACKNOWLEDGEMENTS

The interest and support of this work by the Clifton Hills Pastoral Company is gratefully acknowledged. The provision of staff time and equipment to this survey by Department for Environment and Heritage was vital and Rob Brandle and Peter Canty are thanked for their invaluable expertise and input. Thank you also to Alex Clarke for assistance with field work and use of photos.

REFERENCES

Canty & Brandle (2008) Kowari Dasyuroides byrnei Distribution Monitoring in Sturt’s Stony Desert, South Australia, Spring 2007, unpublished report prepared for the SA Arid Lands Natural Resources Management Board