Behaviour of an asocial carnivore in a social context: social organisation of Tasmanian devils (Sarcophilus harrisii) at the individual level

The Tasmanian devils (Sarcophilus harrisii) is currently listed as endangered due to Devil Facial Tumour Disease (DFTD). Attempts to save the Tasmanian devil from extinction include the establishment of a captive insurance population, with many individuals housed in managed environmental enclosures (MEEs). These enclosures are intended to closely resemble natural conditions for the devil, and aim to preserve natural behaviours within the captive population. To investigate if stable dominance hierarchies exist among devils in MEEs, 70 group-feeding events were audio-video recorded across six reproductive enclosures at Devil Ark (Barrington Tops, NSW) over a 4-month period (April - July 2014). Interactions between a devil approaching food and devils already feeding were analysed according to three possible outcomes: failure, displacement and mutual tolerance. Based on these outcomes, dominance scale scores (BBS method) were calculated for the devils in each enclosure for each month. Results revealed that none of the enclosures exhibited stable dominance hierarchies. However, life history traits of the devils, and time spent feeding did influence contest outcomes, with similar trends having been observed in wild devil populations. The results presented here, when compared with wild observations, reflect positively on the captive environment at Devil Ark both in recreating wild conditions and conserving natural behaviours.