This book is based on observations from field studies and research surveys on the ecology and behaviour of Nilgai, Boselaphus tragocamelus (Pallas, 1766) from selected study areas of Haryana, India. Book will serve the purpose of awareness generation among society as well as students of Life Sciences and other disciplines for conservation and management of ungulates and herbivores at the grass-root level with knowledge of ecology and taxonomy of the species. This document will help to understand the grouping and social organization patterns with reference to different age classes in largest asian antelope species. Different types of grouping styles and measures of sociality will help to understand the behaviour of species. People point of view in the form of opinion is important to understand the social significance of animal species. It will help to implement comprehensive conservation measures for herbivores in degraded habitats of Haryana based on ecological parameters.