Foraging behaviour and sensory ecology of the bat-eared fox (Otocyon megalotis)

[摘要] In the wild, foraging animals face challenges that affect foraging success, including conditionswhich 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 onsensory modalities other than vision in order to locate prey. The auditory mode is particularlyuseful under such conditions; however, various environmental variables may affect this senseas well. Ambient noise for example, may negatively affect foraging success in these hunters.Bat-eared foxes (Otocyon megalotis) are small, nocturnal insectivores noted anecdotally torely 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 threecommon sensory modalities (audition, olfaction and vision) to foraging bat-eared foxes andto 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 foragingfoxes while visual cues would be least so. In the second case, it was predicted that wind noisewould have a deleterious effect on foraging rate outside termite patches and that foxes wouldspend a greater amount of time in termite patches under windy conditions. To test sensoryperception of prey-generated cues, foxes were presented with a choice experiment in whichsensory cues were manipulated. To determine the effect of wind, foraging and meteorologicaldata collected over the course of a year were analysed. The predictions in the first case wereproven correct but foxes continued to be able foragers even under windy conditions, thusrefuting the predictions in the second. Foxes may therefore be able to exploit the temporalstructure of natural noise to overcome foraging challenges imposed or may simply modifytheir foraging behaviour to avoid the effects of masking noise. Future work on the effect ofnoise from other sources, such as anthropogenic noise, as well as determination of theauditory thresholds of these specialised canids will serve to clarify the mechanisms underlying bat-eared fox aural sensitivity.

[发布机构] University of the Free State