Ungulates rely less on visual cues, but more on adapting movement behaviour, when searching for forage

PeerJ. 2017 May 16:5:e3178. doi: 10.7717/peerj.3178. eCollection 2017.

Abstract

Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have no a priori knowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits improve their efficiency when foraging at a heterogeneous habitat patch scale by using visual cues to gain a priori knowledge about potential higher value foraging patches. For each species (zebra (Equus burchelli), red hartebeest (Alcelaphus buselaphus subspecies camaa) and eland (Tragelaphus oryx)), we used step lengths and directionality of movement to infer whether they were using visual cues to find suitable forage patches at a habitat patch scale. Step lengths were significantly longer for all species when moving to non-visible patches than to visible patches, but all movements showed little directionality. Of the three species, zebra movements were the most directional. Red hartebeest had the shortest step lengths and zebra the longest. We conclude that these large grazing herbivores may not exclusively use visual cues when foraging at a habitat patch scale, but would rather adapt their movement behaviour, mainly step length, to the heterogeneity of the specific landscape.

Keywords: Eland; Foraging; Hartebeest; Mkambati Nature Reserve; Movement behavior; Pondoland; Ungulate; Zebra.

Grants and funding

This study was financially supported by the University of Kwazulu-Natal and Eastern Cape Parks and Tourism Agency. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.