Context. Outside its breeding season, the marsupial carnivore the spotted-tailed quoll (Dasyurus maculatus) is apparently largely unaffected by aerial baiting for dingoes and other wild dogs (Canis familiaris). However, the potential impact of aerial baiting during spring on female spotted-tailed quolls carrying and weaning young remains unquantified.
Aim. The survivorship of female quolls and their pouch young was investigated after aerial baiting at two sites representing the northern and southern part of their New South Wales range. The null hypothesis was that aerial baiting would not lead to direct mortality of any adult females or higher pouch young mortality over that reported in the published literature under normal conditions.
Methods. In total, nine female quolls with pouch young and eight male quolls were trapped, fitted with GPS/VHF collars containing mortality sensors and released at their point of capture. After trapping ceased, meat baits nominally containing 6 mg of 1080 and 50 mg of the biomarker rhodamine B were deployed by helicopter at both sites at the maximal permissible rate of 40 baits km^-1. We monitored collared quolls daily for 4-5 weeks for mortality then retrapped animals and sampled whiskers for evidence of the biomarker. The fate of pouch young was also followed throughout our study by examining pouches of adult females and camera trapping at maternal den sites.
Key Results. No collared quolls died. After the daily monitoring period, 10 quolls, including all six collared female quolls, were trapped at the southern site, and whisker samples taken and assayed for Rhodamine B. Seven (4 females and 3 males) tested positive for rhodamine B, indicating consumption of baits. Separate bands of the biomarker in whisker samples indicated that most animals that tested positive had been exposed to multiple baits. At the northern site, four quolls (including two females and two males) tested positive for rhodamine B from the nine sampled. Post-baiting inspection of pouches of all trapped adult female animals, together with camera trapping at den sites, showed that the development of pouch young was unaffected by the baiting. Camera trapping arrays set across both sites continued to record the animals that were exposed to baits well beyond the baiting events, including evidence of breeding in a subsequent season.
Conclusion. Our aerial baiting programs had no observable impact on the collared female quolls, or their ability to raise and wean young. These findings are consistent with results from all previous field-based experimental studies, which show no population-level impacts of 1080 baits on spotted-tailed quolls.
Implications. Land managers should not be concerned about impacts of aerial baiting for wild dogs on spotted-tailed quolls, either in autumn or in spring during the breeding season.

Torpor is a highly effective response to counter various ecological and physiological bottlenecks in endotherms. In this study, we examined interrelations between thermoregulatory responses and key environmental variables in free-living squirrel gliders (Petaurus norfolcensis) in a habitat with drastic climatic and ecological changes across seasons. To this end, we measured body temperature (T_b) and heart rate (f_H) simultaneously throughout the year using implanted data loggers. Squirrel gliders in our study experienced fluctuations in ambient temperature (T_a) between -4.0°C and 44.1°C and expressed torpor at different times during the year. In contrast to our expectations, torpor seemed to be employed flexibly, on demand, and most frequently in spring rather than during the coldest and/or hottest periods. Torpor bouts lasted, on average, about 5 h, and T_b during torpor dropped as low as 17.9°C. The f_H during torpor decreased below 50 bpm, which is about one-third of the basal level. The ability to record f_H alongside T_b enabled us to also report periods of low f_H during thermoconforming hyperthermia at T_a's above 35°C that likely occurred to conserve energy and water. Our findings double the body size of Australian gliders for which data on torpor are available and advance our ecological understanding of the dynamics of torpor expression in wild mammals and of how animals cope with varying conditions. Moreover, they highlight that the flexibility of physiology and thermoregulatory responses are clearly more complex than previously thought.

We show here that evaporative water loss (EWL) is constant over a wide range of ambient relative humidity for two species of small, mesic habitat dasyurid marsupials (Antechinus agilis and Antechinus swainsonii) below thermoneutrality (20 degrees C) and within thermoneutrality (30 degrees C). This independence of EWL from the water vapor pressure deficit between the animal and its environment indicates that EWL is physiologically controlled by both species. The magnitude of this control of EWL was similar to that of two other small marsupials from more arid habitats, which combined with the observation that there were no effects of relative humidity on body temperature or metabolic rate, suggests that control of EWL is a consequence of precise thermoregulation to maintain heat balance rather than a water-conserving strategy at low relative humidities. The antechinus appear to manipulate cutaneous EWL rather than respiratory EWL to control their total EWL by modifying their cutaneous resistance and/or skin temperature. We propose that there is a continuum between enhanced thermoregulatory EWL at high ambient temperature and so-called insensible EWL at and below thermoneutrality.

Decommissioning the dingo barrier fence has been suggested to reduce destructive dingo control and encourage a free transfer of biota between environments in Australia. Yet the potential impacts that over a century of predator exclusion might have had on the population dynamics and developmental biology of prey populations has not been assessed. We here combine demographic data and both linear and geometric morphometrics to assess differences in populations among 166 red kangaroos (Osphranter rufus)—a primary prey species of the dingo—from two isolated populations on either side of the fence. We also quantified the differences in aboveground vegetation biomass for the last 10 years on either side of the fence. We found that the age structure and growth patterns, but not cranial shape, differed between the two kangaroo populations. In the population living with a higher density of dingoes, there were relatively fewer females and juveniles. These individuals were larger for a given age, despite what seems to be lower vegetation biomass. However, how much of this biomass represented kangaroo forage is uncertain and requires further on-site assessments. We also identified unexpected differences in the ontogenetic trajectories in relative pes length between the sexes for the whole sample, possibly associated with male competition or differential weight-bearing mechanics. We discuss potential mechanisms behind our findings and suggest that the impacts of contrasting predation pressures across the fence, for red kangaroos and other species, merit further investigation.

Ecological studies of common brushtail possums (Trichosurus vulpecula) in their extant range have been limited by technology and the species' nocturnal habit. However, camera traps now allow the investigation of possum ethology without observer interference. Here, we analysed terrestrial possum activity patterns using a large dataset collected over 3 years from 133 camera traps in mesic eucalypt woodland and open forest in three national parks on the New England Tablelands, New South Wales, Australia. We investigated how weather and moonlight intensity infuenced possum activity patterns throughout the night, and across seasons and years, by using the timestamps assigned to each detection by the camera trap. Terrestrial possum activity increased as ambient temperatures decreased in autumn and peaked in winter when females were rearing ofspring. Nightly possum detections decreased signifcantly with rain and increasing mean temperature. Possums were almost exclusively nocturnal, with most terrestrial activity earlier in the evening in winter and later at night in summer. During longer nights, higher temperatures also delayed activity. While nightly detection rates were not afected by lunar phase, possums preferred parts of the night with the highest moonlight intensity, and this efect was stronger on brighter nights. Overall, brushtail possums were most active on the ground when temperatures were mild and moonlight bright, presumably assisting foraging and predator avoidance, and during the breeding season" they avoided rain. These patterns suggest that reproduction, thermoregulation and risk of predation strongly shape the nocturnal activity cycle. Furthermore, our research adds to the evidence that camera traps can help greatly expand our knowledge of the ecology and behaviour of nocturnal mammals.

More than two thirds of Australia is arid or semi-arid. These areas are predominately in the centre of the continent and despite the low rainfall and extreme thermal conditions they are inhabited by many and highly diverse animals. The groups that are among the most successful in the arid zone are the ectothermic reptilian skinks (Family Scincidae) and the endothermic carnivorous marsupial mammals (Family Dasyuridae). The aim of my study was to examine behavioural and functional traits that make life in the arid zone possible despite a substantially different thermal biology and energy expenditure. Two locally sympatric burrowing species, the vulnerable great desert skink (Liopholis kintorei, Scincidae) and the brush tailed mulgara (Dasycercus blythi, Dasyuridae) were examined using radio telemetry and behavioural observations. Daily activity patterns and body temperature fluctuations in relation to environmental temperatures were investigated to determine seasonal use of dormancy and burrow use by desert skinks over a 12-month period. Similarly, activity patterns and torpor use, which is characterised by reductions in body temperature and results in a substantial reduction in energy expenditure, and differences between torpor use and home range between summer and winter by mulgaras were investigated.

Great desert skinks spent the majority of their time during their active months at their main burrow (65.8 ± 2.0% of days tracked), but all individuals made regular forays to other burrows (4.1 ± 2.2% of days tracked; (N = 16 (burrows), n = 3), particularly during the spring breeding season. Average L. kintorei T_b during summer was 32.5 ± 1.6°C, during autumn 28.4 ± 2.9°C, during winter 18.4 ± 3.2°C and during spring was 27.7 ± 3.1°C. Liopholis kintorei T_b was significantly different between all seasons (P < 0.005). They were more active than previously thought, displaying predominantly unimodal activity, particularly during autumn and the beginning of winter. In spring skinks were predominantly active after dawn, during the day and ceased activity after dusk. Movement between burrows increased 7-fold between spring and summer (P < 0.001) with females moving within a much smaller home range than males. During spring, skink activity was predominantly unimodal (62.5%) however, showed increased crepuscular and bimodal daily activity patterns (49.4%) during summer. They regularly switched to diurnal and highly unimodal (81.2%) activity in autumn and early winter (99.9%) when ambient temperatures were low. All skinks displayed some level of activity in the cool autumn months but there was no movement between burrows. When daily maximum temperature dropped below ~20°C, all four skinks moved to winter hibernacula 72 – 226 m from their main burrows, where they remained dormant for about three months with body temperatures falling to a minimum of 7.8°C (mean = 14.2 ± 3.5°C). Migration to separate inconspicuous hibernacula during winter may be an anti-predator strategy. Some individuals also estivated from late in summer in chambers at a depth of ~22 cm (mean body temperatures = 32.3 ± 1.8°C; mean soil temperatures at 20 cm = 32.8°C) with one female skink remaining dormant for 50 days from February to April. Because winter brumation occurred at shallow depths (~11 cm) below the surface we suggest this may provide a reproductive advantage by allowing desert skinks to be aroused as early as possible from brumation in spring by being exposed to daily fluctuating cycles of increasing ambient temperatures.

In contrast to skinks, mulgaras were active all year round, but displayed daily torpor mainly during the cold season when the combined effects of cold winter temperatures with reduced food availability also requires regular use of torpor as a means to conserve energy. Mulgaras were largely nocturnal in summer but showed some diurnal activity in winter. Activity appeared to be highest during the first half of the night during both winter and summer. During the winter mating season, males were more active for longer than females irrespective of ambient temperature (P = 0.015), whilst female mulgaras appeared to increase activity with higher night-time temperatures. Duration of activity for both sexes was significantly shorter in winter compared to summer (P < 0.001). Home ranges were larger in winter, particularly for males which were almost four-fold greater than in summer. Ambient temperature and season were found to be significant predictors of mulgaras using daily torpor and there was a statistically significant difference in use of torpor between at summer (8 days/320; 2.5 ± 1.1%) and winter (264 days/301 days; 86.9 ± 8.1%, P < 0.001). In winter, body temperatures in torpid mulgaras fell as low as 11.7°C (mean = 21.8 ± 5.8°C) and the duration of torpor bouts was on average 9 hours. Infrequent, shallow use of torpor occurred during the latter part of summer but with average burrow temperatures of 31.4°C, the ability to reduce body temperatures below the torpor threshold (32°C) appears to have been restricted. Sex had no effect on torpor use during summer, but differences in torpor expression occurred between sexes during winter due to different selective pressures on reproduction (torpor frequency of males = 88.0 ± 10.6%, 150 days tracked, n = 3; females = 85.4 ± 5.8%, 151 days tracked, n = 2). Female mulgaras used deeper and more prolonged torpor than males during winter, however, they ceased using torpor from early spring, presumably once parturition and lactation began. The number of burrows used in summer for both sexes was considerably less than burrows used during winter and overall, females used more burrows than males despite smaller home ranges in winter. Burrow fidelity appeared to be higher in summer than winter for both sexes.

Similarities between the two sympatric species included the home range of males being larger than females during their distinct breeding seasons, along with increased burrow use. Males of both species presumably traversed larger areas to increase opportunities to reproduce. Activity for both species was shorter in winter than in summer and inactivity, whether displayed as daily torpor, estivation or brumation is clearly a significant survival trait to conserve energy and water through periods of low food availability and predator avoidance. My study shows that a combination of functional and behavioural traits permit both species to persist in the arid centre of Australia

Insensible evaporative water loss (EWL) at or below thermoneutrality is generally assumed to be a passive physical process. However, some arid zone mammals and a single arid zone bird can control their insensible water loss, so we tested the hypothesis that the same is the case for two parrot species from a mesic habitat. We investigated red-rumped parrots (Psephotus haematonotus) and eastern rosellas (Platycercus eximius), measuring their EWL, and other physiological variables, at a range of relative humidities at ambient temperatures of 20 and 30°C (below and at thermoneutrality). We found that, despite a decrease in EWL with increasing relative humidity, rates of EWL were not fully accounted for by the water vapour deficit between the animal and its environment, indicating that the insensible EWL of both parrots was controlled. It is unlikely that this deviation from physical expectations was regulation with a primary role for water conservation because our mesic-habitat parrots had equivalent regulatory ability as the arid habitat budgerigar (Melopsittacus undulatus). This, together with our observations of body temperature and metabolic rate, instead support the hypothesis that acute physiological control of insensible water loss serves a thermoregulatory purpose for endotherms. Modification of both cutaneous and respiratory avenues of evaporation may be involved, possibly via modification of expired air temperature and humidity, and surface resistance.

Precocial birds hatch feathered and mobile, but when they become fully endothermic soon after hatching, their heat loss is high and they may become energy depleted. These chicks could benefit from using energy-conserving torpor, which is characterised by controlled reductions of metabolism and body temperature (T_b). We investigated at what age the precocial king quail Coturnix chinensis can defend a high T_b under a mild thermal challenge and whether they can express torpor soon after achieving endothermy to overcome energetic and thermal challenges. Measurements of surface temperature (T_s) using an infrared thermometer showed that king quail chicks are partially endothermic at 2-10 days, but can defend high T_b at a body mass of ~13 g. Two chicks expressed shallow nocturnal torpor at 14 and 17 days for 4-5 h with a reduction of metabolism by >40% and another approached the torpor threshold. Although chicks were able to rewarm endogenously from the first torpor bout, metabolism and T_s decreased again by the end of the night, but they rewarmed passively when removed from the chamber. The total metabolic rate increased with body mass. All chicks measured showed a greater reduction of nocturnal metabolism than previously reported in quails. Our data show that shallow torpor can be expressed during the early postnatal phase of quails, when thermoregulatory efficiency is still developing, but heat loss is high. We suggest that torpor may be a common strategy for overcoming challenging conditions during development in small precocial and not only altricial birds.