Fear, foraging and olfaction : how mesopredators avoid costly interactions with apex predators

• Published in: Oecologia
• Main Authors: Haswell, Peter M., Jones, Katherine A., Kusak, Josip, Hayward, Matt W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Verlag 2018
• Subjects: Mesopredator release; Risk; Gray wolf; Giving-up density (GUD); Red fox (Vulpes vulpes); Canis lupus; gray wolf
• Online Access: http://hdl.handle.net/2263/65070; https://doi.org/10.1007/s00442-018-4133-3

Where direct killing is rare and niche overlap low, sympatric carnivores may appear to coexist without conflict. Interference interactions, harassment and injury from larger carnivores may still pose a risk to smaller mesopredators. Foraging theory suggests that animals should adjust their behaviour accordingly to optimise foraging efficiency and overall fitness, trading off harvest rate with costs to fitness. The foraging behaviour of red foxes, Vulpes vulpes, was studied with automated cameras and a repeated measures giving-up density (GUD) experiment where olfactory risk cues were manipulated. In Plitvice Lakes National Park, Croatia, red foxes increased GUDs by 34% and quitting harvest rates by 29% in response to wolf urine. In addition to leaving more food behind, foxes also responded to wolf urine by spending less time visiting food patches each day and altering their behaviour in order to compensate for the increased risk when foraging from patches. Thus, red foxes utilised olfaction to assess risk and experienced foraging costs due to the presence of a cue from gray wolves, Canis lupus. This study identifies behavioural mechanisms which may enable competing predators to coexist, and highlights the potential for additional ecosystem service pathways arising from the behaviour of large carnivores. Given the vulnerability of large carnivores to anthropogenic disturbance, a growing human population and intensifying resource consumption, it becomes increasingly important to understand ecological processes so that land can be managed appropriately. Table S1: Considerations proposed for the application of the giving-up density framework in field research and how the methodologies created in this paper accounted for these considerations. Table S2: Ethogram describing behaviours recorded (Bold font). Other behaviours that might accompany or be performed alongside those recorded are described in plain text. Bangor University, The UK Wolf Conservation Trust, The Coalbourn Charitable Trust, Ann Vernon Memorial ...