Predation on capped langurs (Presbytis pileata) by cooperatively hunting jackals (Canis aureus)

Predation attempts by cooperatively hunting jackals (Canis aureus) on capped langurs (Presbytis pileata) in moist deciduous forest in north-central Bangladesh are described. The incidents were observed during a 15-m field study of the ecology and behavior of capped langurs. Two attacks on langurs were made cooperatively by, in one instance, a pair and in a second instance a small pack of jackals. One of these attacks was successful. Although P. pileata is a highly arboreal species, both attacks took place in rare instances of ground travel by the langurs.