Researchers have an ethical responsibility to use, and report on, methods that minimise death and injury to study animals. We developed safe capture and tagging methods for an Australian crane, the brolga, after published methods proved ineffective or posed a welfare risk for this species. Use of call playback and taxidermy decoys with our noose trap design can reduce capture-related deaths and injuries to brolgas, and other crane species with similar behaviour. Photograph by Inka Veltheim.
Volume 42 Number 5 2015
Understanding the processes that regulate animal populations is a central theme in ecology. We test predictions of hypotheses concerning food limitation, competition, predation, disease and land use changes on buffalo population dynamics in an African savanna – the Mara–Serengeti Ecosystem. Buffalo population growth is apparently regulated by density-dependent food limitation and interspecific completion. The effects of density-dependent food limitation, interspecific competition, predation and land use changes on the Mara–Serengeti buffalo population are amplified by recurrent El Niño droughts, thus prolonging the recovery times and threatening the persistence of buffalo populations. Photograph by Reto Buehler.
WR15092Spatially explicit capture–recapture analysis of bobcat (Lynx rufus) density: implications for mesocarnivore monitoring
Density estimates for carnivores (number of individuals per unit area) are fundamental to successful conservation and management, yet remain challenging to obtain for many species. We used camera trapping and recently developed statistical methods to generate precise density estimates of a common carnivore, the bobcat, in Texas. Our results highlight the utility of this method for density estimation of small carnivores, and also indicate that if such methods are combined across multiple studies, inference about regional variability in density is achievable.
WR14183Using site-occupancy models to prepare for the spread of chytridiomyosis and identify factors affecting detectability of a cryptic susceptible species, the Tasmanian tree frog
Although the disease chytridiomycosis has spread globally and caused severe amphibian decline, some remote regions in Australia remain disease free. In order to detect the spread and impact of chytridiomycosis, we used multistate site-occupancy modelling. Although we did not detect spread or impact, this approach has the potential to provide an early warning for cryptic species threatened by a spreading disease and enable a relatively rapid conservation response.
WR15054The effectiveness and cost of camera traps for surveying small reptiles and critical weight range mammals: a comparison with labour-intensive complementary methods
Improving research methods can reduce survey and management costs of wildlife, especially for cryptic species. Camera traps were found to be less costly than traditional methods while being more effective for mammals and as effective for reptiles. Researchers using camera traps to survey critical weight range mammals can confidently include small reptiles as target species in surveys with little extra cost, and herpetologists can confidently adopt camera traps as a reliable survey tool.
The introduction of the grey squirrel has resulted in a reduction of red squirrel only areas and limited data on the habitat preferences of reds. This research aimed to examine red squirrel habitat preferences in an area which is currently free of grey squirrels to investigate tree species which could give reds a competitive advantage. Yew, a species that is used little by greys, was selected most commonly by red squirrels, indicating the importance of this species in red squirrel management.
WR14233The role of the bandwidth matrix in influencing kernel home range estimates for snakes using VHF telemetry data
The performance of many kernel home range estimators with handheld radio telemetry data from many small-bodied taxa remains largely unexplored. We evaluated multiple kernel home range estimators from two snake species and found that estimators varied in their performance relative to the five criteria we considered. Our study provides guidelines to help researchers choose a kernel home range estimator that best suits their data and study objectives. Photograph by Kevin Stohlgren.
Band-tailed pigeons are a migratory species whose populations have undergone long-term declines despite high breeding season survival. We used VHF and PTT transmitters to estimate survival during four seasonal periods and found that threats to survival are greatest during migration periods and lowest during the nesting period. These findings may affect species management including harvest and disease monitoring strategies. Photograph by Cory Overton.