Maps of the distribution of the two currently recognised species of Dasycercus, D. blythi and D. cristicauda have been prepared following correct identification based on tail morphology of specimens in the modern collections of all Australian museums. Localities in which the remains of Dasycercus have been found in cave deposits have also been mapped and an attempt made to determine the specific identity of some of these specimens. Following examination of larger samples of each species, differences in the premolar dentition were found to no longer be diagnostic. Most cave specimens could not be assigned to species on the basis of some dental measurements. DNA sequences could provide a means for establishing the identity of the cave specimens. Correct identification of specimens, together with knowledge of the search effort underlying the known distribution and persistence of the species in localities over their ranges, is essential for assessment of their conservation status.

Common dolphins are subject to large-scale fishing activity and tourism operations in South Australia; however, there is a paucity of data on this species. Understanding the behaviour of a population can contribute greatly to our knowledge of a species and how to manage potential population-level threats. This paper describes the behaviour of short-beaked common dolphins (Delphinus delphis) in Australian waters for the first time. Data were collected from 109 independent dolphin groups during boat-based surveys conducted in Gulf St Vincent, South Australia, between September 2005 and May 2008. Activity budgets were used to assess behaviour of common dolphins in relation to diel patterns, season, water depth, sea surface temperature (SST), group size and composition. Foraging (33.9%) and resting (2.8%) were the most and least frequently observed behaviours, respectively. Travelling (33.0%), socialising (20.2%) and milling (10.1%) accounted for the remainder of the activity budget. Diurnal differences were detected, with foraging (59.5%) and socialising (31.8%) groups most frequently observed from 10.00 to 11.59 hours. Behaviour did not vary seasonally or with water depth, SST, group size or composition. Behaviour varied significantly between single- and multispecies aggregations. Foraging was more frequent in multispecies aggregations, as 78.4% of all foraging behaviour observed for common dolphins occurred in the presence of other species. Multispecies aggregations were most frequently observed with flesh-footed shearwaters (Puffinus carneipes), which were present during 29.4% of common dolphin encounters. Behaviour varied significantly during aggregations with shearwaters, as 62.2% of foraging groups occurred in the presence of shearwaters. Resting, milling or socialising was rarely observed in the presence of any other species, indicating that the primary mechanism for aggregations is likely prey-related.

Immune responsiveness, the ability of an organism to effectively respond immunologically following antigenic exposure, is an essential component of life history, as organisms require effective immune functionality in order to grow, survive and reproduce. However, immune status is also associated with concomitant trade-offs in these physiological functions. Herein we demonstrate the validation of phytohaemagglutinin (PHA) injection in saltwater crocodiles, Crocodylus porosus, to assess cellular immune responsiveness. Following injection of 2 mg mL^–1 PHA into the hind toe webbing, we observed a peak swelling response 12 h after injection, with PHA inducing increased thickness compared with webs injected with phosphate-buffered saline (PBS) (F_5,518 = 145.13, P < 0.001). Subsequent injections increased responsiveness relative to the primary injection response (F_5,290 = 2.92, P = 0.029), suggesting that PHA exposure induced immunological memory, a tenet of acquired immunity. Histological examination revealed that PHA-injected toe webs displayed increased numbers of leukocytes (granulocytes, macrophages, and lymphocytes) relative to PBS-injected webs, with peak leukocytic infiltrate observed 12 h after injection. We suggest the use of PHA injection in crocodilians as a measure of cellular immune responsiveness in agricultural (production and animal welfare), ecological, and toxicological contexts.

For herbivores, vigilance usually involves a trade-off with foraging, and a further trade-off between antipredator and social vigilance. Thus individual variation in vigilance may result in significant fitness consequences. We used mixed-effects models to document individual variation in vigilance in wild adult female eastern grey kangaroos (Macropus giganteus) in Queensland, Australia. We tested the effects of group size, presence of adult males and wind on vigilance patterns and variation by analysing 399 five-minute samples on 31 individually identified females who were foraging on the periphery of groups. We determined the proportion of time that individuals spent vigilant, and the proportions of vigilance time spent in social versus antipredator vigilance and in low- versus high-intensity vigilance postures. The proportion of time females spent vigilant decreased with increasing group size but was not affected by wind speed or male presence, while the amount of their vigilance time spent in social vigilance was affected by interactions among the variables. After controlling for these effects, 13 females’ vigilance patterns were significantly different from the population mean. Individual variation was also found in vigilance postures used and the effect of male presence. Understanding individual variation in vigilance is important for understanding individuals’ antipredator and social strategies.

Variations in larval sensitivities to atrazine were determined in the Australian native striped marsh frog, Limnodynastes peronii, and the introduced cane toad, Rhinella marina. The static acute test design involved six nominal concentrations of atrazine, including control, solvent control, 3, 6, 12, and 24 mg L^–1. Gosner stages 22–23 as hatchlings, stages 25–26, 28–29, and 32–33 as premetamorphic, 36–37 as prometamorphic and 40–41 as metamorphic climax stages of cane toads and the first four sets of Gosner stages of striped marsh frogs were exposed to atrazine treatments for 96 h. Results showed that late larval stages were more sensitive than early stages and different premetamorphic stages showed variations in sensitivities in both test species. The striped marsh frog showed a stronger concentration- and stage-dependent response and greater sensitivity to atrazine than the cane toad. In both experimental species, Gosner stages 28–29 showed better concentration-dependent increase in sensitivities to atrazine compared with other larval stages. It can be concluded that inter- and intra-species variations in sensitivities to atrazine may occur in Australian anurans and native species may show greater sensitivity to acute concentrations of atrazine than the introduced cane toad.

The population dynamics of the Australian plague locust, Chortoicetes terminifera, are strongly linked to the timing and distribution of heavy rainfall events in semiarid and arid environments. While the effects of insufficient rainfall on survival are relatively well understood, little information exists on the effects of excessively wet conditions. This study aimed to quantify the survival of first-instar C. terminifera nymphs to a range of water-immersion periods and temperatures. Results show that survival is strongly dependent on immersion temperature whereby survival times ranged from time to 50% mortality (LT₅₀) = 8.12 ± 0.26 h at 15°C to 4.93 ± 0.30 h at 25°C. Nymphs entered a coma-like state within 2 min of immersion. Post-immersion recovery times were greater for longer immersion periods and longer at higher temperatures for immersion periods of >3 h. These findings suggest that first-instar nymphs would be able to survive most instances of transient, localised pooling of water associated with heavy rainfall in the field. However, flooding that could trap individuals for >5 h (including nymphs still underground within the egg pod before emergence to the soil surface) has the potential to cause high mortality, particularly during summer and early autumn when water temperatures may be high.

Vigilance is an essential component of antipredator behaviour and is also used to monitor conspecifics, but is traded off against feeding in herbivores. This trade-off can be influenced by variation in many environmental, social and individual traits. Our aim was to test the relationship between individual-level traits, including boldness, body condition and reproductive state, and vigilance, while controlling for environmental and social variables. Using multiple 5-min video samples of 30 foraging, individually recognisable, female eastern grey kangaroos (Macropus giganteus) at Sundown National Park in Queensland, we investigated individual-level variation in the duration, intensity and target of vigilance behaviour during foraging. On separate occasions, we used flight-initiation distance tests to measure boldness in our kangaroos. Females with longer flight-initiation distances (shyer females) spent more time vigilant, providing preliminary support for studies of animal personality that have suggested that boldness may covary with vigilance. Body condition did not affect the total time spent vigilant, but females in poorer body condition spent more of their vigilance time in low-intensity vigilance. Vigilance patterns were not related to reproductive state, but varied among months and differed between mornings and afternoons, and females spent more time in high-intensity vigilance when further from cover. Even after accounting for all our variables we found that 7% of the variation in total time vigilant and 14% of the variation in vigilance intensity was explained by individual identity. This highlights the importance of individual-level variation in vigilance behaviour.

We used scat and isotope analyses to assess insectivory in Fijian flying foxes (Pteropodidae), seeking insights into niche partitioning of co-occurring bat species with high plant diet overlap. Moth scales were most common in scats of Notopteris macdonaldi (87%; P. tonganus: 62%; Pteropus samoensis: 36%) and may indicate shared resources. The small and highly manoeuvrable N. macdonaldi exploited nectar-rich flowers also favoured by moths (e.g. Barringtonia spp.). Other invertebrate remains were most frequent in scats of P. tonganus (69%). On the basis of scat results and ecological observations, P. tonganus uses a combination of insectivory and a highly varied plant diet to obtain sufficient nutrients. Scats of P. samoensis contained few invertebrate remains, but abundant protein-rich plant species (including Freycinetia spp.), and juveniles seemed to consume moths frequently. Clustered δ¹⁵N and δ¹³C for N. macdonaldi and P. samoensis indicated a narrower dietary breadth than that of P. tonganus. P. tonganus juveniles appeared at a significantly higher trophic level than did adults, probably the result of milk consumption and/or higher rates of protein synthesis. The methods used detected little evidence that bats partitioned resources vertically. This study generates hypotheses for the further examination of flying-fox diets.