Rusa unicolor, commonly known as the sambar deer, inhabits dense forests across South and Southeast Asia. Notable for its large size, shaggy coat, and distinctive antlers, it is a primarily nocturnal grazer. Sambar deer are key prey for apex predators and play a vital role in forest ecosystems.

The Rusa unicolor, commonly known as the sambar deer, is native to South Asia, Southeast Asia, and the southern regions of East Asia. Its geographical distribution includes countries such as India, Sri Lanka, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Vietnam, Laos, Cambodia, Malaysia, Indonesia, and parts of southern China.

Sambar deer typically inhabit tropical and subtropical forests, including both deciduous and evergreen forests. They are often found in hilly and mountainous regions, ranging from sea level up to elevations of 3,500 meters. The climate in these areas can vary from humid tropical to subtropical, with distinct wet and dry seasons.

Sambar deer are primarily browsers, feeding on a variety of vegetation including leaves, grasses, herbs, and fruits. They play a significant role in their ecosystem by influencing plant community dynamics and serving as prey for large predators such as tigers and leopards. Their ability to adapt to different forest types and elevations showcases their ecological flexibility.