02656nas a2200253   4500008004100000022001400041245013100055210006900186260001600255520187700271653001202148653001802160653001502178653001602193653002102209100001202230700001802242700001502260700001602275700001602291700001402307700001902321856006202340       2019                        eng d  a0067-223800aUsing Passive Acoustic Recording and Automated Call Identification to Survey Koalas in the Southern Forests of New South Wales0 aUsing Passive Acoustic Recording and Automated Call Identificati  cJul-10-20213 a<p>Cost-effective surveys of low density koala populations are challenging, but technological developments in the acoustics field offer great potential for landscape-scale surveys and monitoring. We assessed passive acoustic recording coupled with automated call identification as a survey method for koalas Phascolarctos cinereus. Surveys targeted areas of previously known koala activity based on scat surveys in southern forests of New South Wales where a low density of koalas is suspected. We set 24 Song Meters to record at night over a two week period (~3,696 hours) in the koala breeding season (October/November) in Murrah Flora Reserve. Recordings were scanned by a koala call recogniser and &ldquo;matches&rdquo; were manually verified. Across the 24 sites, 522 validated koala bellows were recorded at 21 sites (87.5 % detection rate). Three environmental variables had most influence on detection probability of koalas, including nightly rainfall (-ve), nightly temperature (-ve) and topographic position (lower on ridges). Calling activity peaked at midnight. Sustained site occupancy, at least in the short-term, was apparent as under optimal conditions (no rain) koalas were recorded, on average, for &gt; 50 % of survey nights rather than for just a few nights. We suggest that only a modest survey effort (4&ndash;5 nights) in the breeding season, on nights with &lt; 3 mm of rain, is required to achieve 90&ndash;95 % probability of koala call detection in an area of low koala density. Comparison with scat surveys at the same sites revealed that detection rates were more than three times greater with acoustic surveys. Technological advances will continue to provide improvements for wildlife survey, and perhaps most importantly, for collecting much needed long-term data to assess trends in occupancy or other population attributes over time.</p>
10abellows10adetectability10amonitoring10aSong Meters10aWildlife surveys1 aLaw, B.1 aGonsalves, L.1 aBilney, R.1 aPeterie, J.1 aPietsch, R.1 aRoe, Paul1 aTruskinger, A.  uhttp://publications.rzsnsw.org.au/doi/10.7882/AZ.2019.03302184nas a2200193   4500008004100000245007800041210006900119260001600188300001400204490000800218520156700226653001101793653003201804653002501836100002701861700002401888700002401912856005401936       2017                        eng d00aSubharmonics increase the auditory impact of female koala rejection calls0 aSubharmonics increase the auditory impact of female koala reject  cJan-08-2017  a571 - 5790 v1233 a<p>Although non-linear phenomena are common in human and non-human animal vocalisations, their functional relevance remains poorly understood. One theory posits that non-linear phenomena generate unpredictability in vocalisations, which increases the auditory impact of vocal signals, and makes animals less likely to habituate to call repetition. Female koalas (Phascolarctos cinereus) produce vocal signals when they reject male copulation attempts that contain relatively high levels of non-linear phenomena, and thus may function as attention grabbing vocal signals during the breeding season. To test this hypothesis, we used playback experiments: firstly, to determine whether female rejection calls induce heightened behavioural responses in free-ranging male koalas during the breeding season, and secondly, to examine how the relative amount of non-linear phenomena in rejection calls influences male behavioural response. The results show that male koalas look for longer towards speakers broadcasting playback sequences of male bellows followed by a series of female rejection calls than those broadcasting only male bellows. In addition, female rejection call sequences with more subharmonics, higher harmonics-to-noise ratios, and less biphonation produced the greatest male looking responses. Our findings support the hypothesis that female koala rejection calls function to grab male attention during the breeding season, and indicate that subharmonics are the main acoustic feature that increases the auditory impact of these vocal signals.</p>
10akoalas10amammal  vocal communication10anon-linear phenomena1 aCharlton, Benjamin, D.1 aWatchorn, Darcy, J.1 aWhisson, Desley, A.  uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-8