| Popis: |
New South Wales, including the small enclave of the Australian Capital Territory (ACT), has a diverse bat fauna of 39 taxa (34 microchiropterans and 5 megachiropterans). In NSW, 22 (56%) of chiropteran taxa are listed as threatened, 20 as vulnerable, one as endangered and one extinct under the NSW Threatened Species Conservation Act/995.There are no threatened bats listed in the ACT under the Nature Conservation Act 1980. We mapped the geographic distribution and relative density of specimen and observation data (excluding ultrasonic records because of the uncertainty of identification) for each species using weighted Kernel Density Estimate models based on 96,000 unique records of more than 3 million individual bats observed in NSW and ACT. We investigated the use of existing distribution and observation data to identify trends in reporting rates for each taxon over the past decade using a non parametric rank analysis to determine the annual ratio of observations per species versus a surrogate for effort. We also investigated regional patterns in the distribution of the bat fauna using PATN association and classification analysis to identify 6 distinct 'bat regions' based on the species composition of the 18 biogeographic regions within NSW and ACT. We found that survey effort and data were unevenly distributed spatially, taxonomically and temporally. Fifty-six percent of all records are from three coastal bioregions, 5 species account for 52% of all records, and conversely over 50% of the species account for less than 5% of all records. Further, most (60%) of the records are from the last 20 years. As most of our data are from large-scale, inventory type surveys, we recommend that greater attention should be devoted to targeted research and long-term monitoring. Without monitoring, identifying trends in species and populations is almost impossible.The status of most bats will remain threatened without action to ameliorate threats and monitor changes in population sizes and their distribution. |
