Factors affecting vigilance in springbok: importance of vegetative cover, location in herd, and herd size | Semantic Scholar

Time spent looking varied with position within the group; this effect was strongest in closed habitats, where central animals tended to scan least and feed most, and within species, animals inclosed habitats, those with dense vegetation, tended to spend more time in looking than did animals in the open.

It is concluded that vigilance in buffalo was not restricted to predator detection, and that in periods in which epidemics or drought conditions are absent it was normal that ultimately some 90% of the large herbivores fell victim to predation.