The Farasan gazelle—A frugivorous browser in an arid environment?

Abstract

Food preferences of Arabian gazelle (Gazella arabica) on Farasan Islands, Saudi Arabia, were evaluated using focal animal sampling, ‘food tracking’ and an eco-morphological method examining tooth wear. Behavioural observations showed that gazelles generally consumed foliage, fruits and flowers of trees and shrubs, and to much lower extent annual and perennial herbs. Grass represents only 4.4% of the total time spent feeding at ground level. During dry season, gazelles spent significantly more time browsing on trees and shrubs and less time browsing on herbs than under wet conditions. Thus, consistent with predictions, gazelles are selective browsers. Major food plants are Acacia ehrenbergiana, Corchorus depressus and Capparis sinaica. During dry season the time spent feeding on fallen pods of Acacia and the time spent browsing on hind legs significantly increased. No sexual and age-related differences in the dietary choice of gazelles were revealed. The tooth wear signature of Farasan gazelles is dominated by abrasive food components classifying them with seasonally variable browsers and frugivorous dwarf ungulates. Based on the feeding behaviour we linked abrasion to the high mineral component of pods. Since the Farasan Islands are subject to high dust load, we also attribute the observed tooth wear signal to the high grit load.