Foraging behaviour and sensory ecology of the bat-eared fox (Otocyon megalotis)
In the wild, foraging animals face challenges that affect foraging success, including conditions which influence the usefulness of the sensory input they receive from their environment. Nocturnal foragers must cope with diminished light availability and may come to rely on sensory modalities other than vision in order to locate prey. The auditory mode is particularly useful under such conditions; however, various environmental variables may affect this sense as well. Ambient noise for example, may negatively affect foraging success in these hunters. Bat-eared foxes (Otocyon megalotis) are small, nocturnal insectivores noted anecdotally to rely primarily on acoustic cues in prey detection, though this has not been empirically tested. The aim of the current study was therefore to determine the relative importance of three common sensory modalities (audition, olfaction and vision) to foraging bat-eared foxes and to examine the effect of naturally occurring ambient noise on the auditory sense in particular. In the first instance, it was predicted that auditory cues would be most salient to foraging foxes while visual cues would be least so. In the second case, it was predicted that wind noise would have a deleterious effect on foraging rate outside termite patches and that foxes would spend a greater amount of time in termite patches under windy conditions. To test sensory perception of prey-generated cues, foxes were presented with a choice experiment in which sensory cues were manipulated. To determine the effect of wind, foraging and meteorological data collected over the course of a year were analysed. The predictions in the first case were proven correct but foxes continued to be able foragers even under windy conditions, thus refuting the predictions in the second. Foxes may therefore be able to exploit the temporal structure of natural noise to overcome foraging challenges imposed or may simply modify their foraging behaviour to avoid the effects of masking noise. Future work on the effect of noise from other sources, such as anthropogenic noise, as well as determination of the auditory thresholds of these specialised canids will serve to clarify the mechanisms underlying bat-eared fox aural sensitivity.