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Koala scat surveys are important tools for determining koala presence and distribution in large forested areas where it is impractical to conduct direct observation surveys. However, current scat survey methods are problematic due to lack of either accuracy or feasibility, i.e. they are either biased or very time-consuming in the field. This study aimed to establish a new koala scat survey method with improved accuracy compared with existing methods, and practical in the field. We developed a new Balanced Koala Scat Survey method (BKSS), and evaluated it in the field by analysing scat detectability variations and comparing it with a current survey method, the Spot Assessment Technique (SAT), to determine scat searching accuracy. The results revealed that current methods were biased by assigning consistent searching effort for all trees, because effective searching time to detect the first scat was significantly affected by Koala Activity Level (KAL – the proportion of trees found with scats among all 30 trees in a survey site). Compared with BKSS, SAT tended to yield more false negative outcomes; SAT may miss up to 46% of trees with scats when KAL was low. The application of BKSS is expected to greatly enhance the reliability of koala scat surveys in determining koala distribution and thus improve their conservation management.
Five species are currently recognised in the dasyurid genus Murexia, i.e. longicaudata, naso, habbema, melanurus and rothschildi. Morphological data, including spacing of premolar teeth, the footpads and aspects of external appearance, together with nuclear and mitochondrial DNA sequences from multiple exemplars from across the range of each species, suggest that at least three of these represent species groups rather than individual species. Some of the taxa currently synonymised in the five species may warrant reinstatement, including M. murex, M. aspera, M. maxima in the ‘M. longicaudata’ group, M. tafa in the ‘M. naso’ group and M. wilhelmina in the ‘M. melanurus’ group. Our data also suggest the presence of other, synonymised or undescribed taxa within the ‘longicaudata’, ‘naso’, ‘melanurus’ and ‘habbema’ species groups whose species boundaries require clarification by further collections and study.
We monitored some aspects of maternal care in Australia’s second largest extant marsupial predator, the spotted-tailed quoll. We radio-collared six females carrying young at an early pouch stage in the Byadbo Wilderness in southern New South Wales in August–September 2016. When these young were deposited at a maternity den at a still altricial state we monitored den activity of the female and her young with motion-triggered camera traps. Lactating females remained in the same den for up to 39 days before moving to a new den, usually only a few hundred metres away. Females furnished dens with nesting material, but were never observed to carry prey nor were the young seen consuming solid food. They were also surprisingly tolerant towards visits and den use by wombats, rabbits, possums and male quolls. Females showed predominantly nocturnal activity, but usually returned at least once per night. Short daytime activity was also common. In contrast, juveniles were initially exclusively diurnal, probably to facilitate behavioural thermoregulation, and only later extended their playing and exploring towards dawn and dusk. Hence interactions between mother and young were rarely observed. Apparently, the young received little training from their mother and simply ventured further and for longer periods away from the den until independence.
Several genera of anuran amphibians deposit their eggs within mucous secretions that have been aerated by the parents to produce a foam or bubble spawn body. This is a dynamic medium for embryo development given that it gradually breaks down over time, and one that has been hypothesised to serve a variety of purposes including protecting embryos from external stresses, such as suboptimal temperatures, desiccation and predation. In this study, I provide additional details of bubble spawn production in the sandpaper frog, Lechriodus fletcheri. Field and laboratory observations showed that females aerate spawn while in inguinal amplexus, using flanged fingers to transport air bubbles into the mucous. While the frothed spawn is initially resistant to breakdown, it gradually loses bubbles and flattens out into a film. This temporal shift in structure is likely to be adaptive, as the resultant increase in surface area allows embryos to come in direct contact with the open water, which may accommodate their increased oxygen demands or ease extrication from the mass. I provide evidence that this process is controlled by the residing embryos, given that spawn in the absence of embryos does not break down, highlighting the ability of offspring to modify their immediate environment even before hatching occurs to ensure conditions remain suitable for their changing needs.
Phylogenetic relationships and estimated dates of origin, plus distributional, ecological and morphological data for salticid genera were used to examine a series of hypotheses related to the evolution of the Australian salticid fauna. Though independent, the time patterns of evolution of genera in Australia and South America were similar, while that for Northern Hemisphere taxa differed. In each case the production of new genera occurred during the warmer parts of the mid Tertiary but not during cooler and drier times. Asian elements entered Australia as early as 31 million years ago, long before the collision of the Australasian and Asian continental plates. Endemic and derivatives of Asian genera were similarly distributed across Australian biomes. However, arriving taxa were more successful when conditions matched their mesic origins (tropical), but less so when different (temperate). While endemic genera often extended their ranges into drier environments by increasing the number of species, recent arrivals did so by extending the range of individual species. Maximum Parsimony analyses of a range of presumed adaptive, morphological and ecological characters showed these did not reflect genus-level processes; however, the analysis did show all endemic genera had mesic origins.
Long-nosed fur seals (Arctocephalus forsteri) were tagged as pups in colonies on Kangaroo Island, South Australia in eight consecutive pupping seasons from 1988–89 to 1995–96. Thirty-nine tagged animals were sighted on the southern Australian coast, being 0.89% of those tagged. They were aged from 9 months to 14 years 6 months, with half in their second and third years. Most records (88%) were of animals that moved eastwards. The most distant records were from Sydney in the east (1700 km), south of Tasmania in the south (1240 km) and Head of Bight in the west (700 km). One animal was seen twice, both times on the north coast of Kangaroo Island, once underwater and two years later ashore. Satellite telemetry studies of juvenile A. forsteri from Kangaroo Island showed that they typically forage in pelagic waters ∼1000 km further south in association with the subtropical front. The study reported here shows that some animals tagged as pups disperse widely as juveniles around the southern Australian coast. The possibility of genetic interchange between breeding colonies is suggested by sightings of three tagged females aged 4 years and older at non-natal colonies.
Most reptiles exhibit no parental care and aggressive behaviour towards heterospecific predators has rarely been recorded in the natural environment. Several species of the subfamily Egerniinae are amongst the most highly social of all squamate reptiles, exhibiting stable social aggregations and high levels of long-term social and genetic monogamy. We have examined Cunningham’s skinks, Egernia cunninghami, over a three-year period during late January and early February (total 32 days) in the alpine region of New South Wales using video and thermal imaging. Four birthing sessions were witnessed during our field studies of social aggregations of skinks. Our observations monitored skink encounters, in the presence of offspring, with an eastern brown snake, Pseudonaja textilis (two separate encounters, one recorded by video/imaging) and 12 encounters with the Australian magpie, Gymnorhina tibicen. All events were associated with aggressive chasing and/or attack by adult skinks. The first snake encounter involved the active targeting of a recently born juvenile with the mother of the juvenile attacking the snake (running towards the snake, biting and remaining attached for several seconds). The second encounter (the following year) comprised two adult skinks attacking and biting a snake, Pseudonaja textilis. All magpie encounters resulted in chases by adult skinks.
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