Effects of food supplementation from tourism on crocodile bioenergetics and abundance

Tourism operators frequently use supplemental feeding to enhance wildlife viewing experiences, particularly in wildlife tours. While the effects of such feeding practices on animal behaviour are well-documented, their contribution to the energetic requirements of the target species has received significantly less attention. In Australia, jumping crocodile tours utilise meat to attract estuarine crocodiles (Crocodylus porosus) to boats, encouraging them to leap from the water. This study aimed to assess the extent to which the meat provided by these tours sustains the daily energy requirements of the crocodiles and how this, in turn, might influence crocodile abundance and biomass. The amount fed during crocodile tours is not generally measured and varies within and between tours. Therefore, we estimated a range of feeding scenarios, from which 60 %–180 % of the daily energetic requirements for the crocodiles residing in the designated feeding area could be met. We also found that crocodile abundance and biomass were statistically greater within the feeding area. While our findings do not definitively indicate a positive or negative effect of feeding upon the local estuarine crocodile population, it does provide insights into the potential impact tourism-based supplemental feeding may have on wild crocodile populations and provide information to assist the development of practice guidelines.