Food Habits of Nilgai Antelope in Texas

Abstract

A 2-year food habit study of the nilgai antelope (Boselaphus tragocamelus) and its forage selections compared with white-tailed deer (Odocoileus virginianus) and cattle was conducted in south Texas. Rumen analyses of 79 nilgai and 40 deer, collected on various feeding sites, and bite studies on the same sites using two captive nilgai and a trained steer showed no significant difference (P>0.05) in forage classes taken between the 2 methods. Nilgai preferred to feed on large open areas interspersed with cover and ponded water. They were grazers, their average diet consisting of 60% grasses, 25% forbs, and 15% browse. They augmented the nutritive level of their basic diet by selecting nutritious plant parts and changing their selections as the parts appeared, waned, and fluctuated in quality with the seasons. When food was scarce, nilgai ate more browse, dead vegetation, and dry dung of large herbivores. The quality and quantity of their forage was within the levels published for cattle and North American big game. They maintained a feeding role intermediate between cattle, which used mainly grass, and deer, which used forbs heavily. When food supply and variety was low, nilgai competed strongly with cattle for grass and deer for forbs. The 3 species seem compatible where there is good variety of browse and herbage, and control of their respective numbers.