[6][7] It is thought to have been introduced to western Bangladesh by Hindu pilgrims on the bank of the Jalangi River.
[6][7] The northern plains gray langur eats primarily fruits and leaves.
[6] It also eats seeds, flowers, buds, bark and insects, including caterpillars.
[6] It is also fed fruits and vegetables by humans, and some groups get a substantial portion of their diets from food provided by temples and from raiding crops.
[6] The northern plains gray langur often associates with chital deer.
[7] It is subject to some threats, including road kill, attacks by dogs, forest fires and diseases caught from domestic animals.
[2][7] It is sometimes hunted for food, especially within the states of Odisha and Andhra Pradesh and is sometimes killed by humans to prevent it from raiding crops.
[2] Captive gray langurs are used in Delhi to scare off rhesus macaques, which steal from and sometimes attack people.