A review of intervention methods used to reduce flying-fox mortalities in heat stress events

Heat stress events in Australian flying-fox camps have resulted in significant numbers of flying-fox deaths. The frequency and intensity of such events have increased in recent decades, attributed to anthropogenic climate change. Evidence-based interventions are required to address this growing threat. Responders currently use different combinations of a range of intervention methods. We undertook a systematic review of heat stress interventions, which we classified as either ‘camp-scale’ or ‘individual-scale’. Camp-scale interventions included manual and automated misting of roost vegetation, whereas individual-scale interventions included spraying individual animals or removing them for intensive cooling and rehydration procedures. Our study showed that to date, evaluation of the efficacy of heat stress interventions has been largely anecdotal rather than empirical. This highlights the need for dedicated rigorous studies to evaluate the effectiveness of all the intervention methods described here. It will be especially important to understand the relationship between camp temperature and humidity levels and their influence on flying-foxes’ ability to regulate their body temperature, because high relative humidity reduces the ability of mammals to cool themselves using evaporative heat loss. The development of biophysiological measures such as temperature and humidity indices for different flying-fox species would enable meaningful interpretations of intervention trials under controlled conditions.

Observations on the behaviour of the northern hairy-nosed wombat (Lasiorhinus krefftii) in a translocated population

The natural distribution of the critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii) is confined to Epping Forest National Park, Queensland; however, a small number of animals have been translocated to establish an insurance population at Richard Underwood Nature Refuge (RUNR), Queensland. Northern hairy-nosed wombat behaviour is poorly understood, mostly due to its cryptic behaviour. Thirty-two wildlife cameras set up at burrow mouths at RUNR were used to capture social and solitary behaviour. Over a six month period between December 2016 and May 2017, 0.3% (21 videos of 6607) of recordings captured social behaviour, suggesting that the northern hairy-nosed wombat actively avoids social interactions at the burrow mouth. Vocalisation was only observed during social interaction. The results were similar to data from Epping Forest National Park and studies on other wombat species. In this respect the translocated population appeared to behave in a manner typical of the wild population.