Mammals
Irrawaddy Dolphin
Orcaella brevirostris · also called Irrawaddy dolphins
Working alongside local fishers on a Southeast Asian river, an Irrawaddy dolphin herds a school of fish toward a waiting net, a genuinely rare form of cooperation between a wild marine mammal and people that has been documented for generations in parts of this species’ range.
Overview
The Irrawaddy dolphin, Orcaella brevirostris, is a rounded-headed, beakless dolphin native to coastal and river habitat across a range spanning South and Southeast Asia and parts of northern Australia. Its distinctive whale-like appearance, remarkable documented history of cooperative fishing with people, and severely threatened isolated freshwater river populations make it one of the more behaviourally unique and conservation-urgent dolphin species found anywhere in the world.
A dolphin that works with people
Few marine mammals anywhere have developed as well-documented a cooperative relationship with humans as the Irrawaddy dolphin, whose fish-herding partnership with local fishers represents one of the more remarkable examples of interspecies cooperation in nature.
Status
Endangered, present across suitable coastal and river habitat throughout South and Southeast Asia, with several isolated freshwater river populations facing severe, critically endangered-level threats.
Irrawaddy Dolphin: common questions
Why does the Irrawaddy dolphin look different from most other dolphins?
This species has a distinctively rounded head without a pronounced beak, an appearance that gives it a somewhat whale-like or porpoise-like look quite different from the more typically beaked profile seen in many other dolphin species sharing similar coastal and river habitats.
Does the Irrawaddy dolphin really help fishers catch fish?
Yes, this species has a long documented history of cooperative fishing with local communities in parts of its range, helping herd fish toward fishing nets in exchange for a share of the catch, a genuinely rare and well-documented form of cooperation between a wild marine mammal and people.
Why are some Irrawaddy dolphin populations more endangered than others?
This species includes several small, isolated freshwater river populations that face severe threats from habitat degradation, dam construction, and entanglement in fishing gear, pressures considerably more intense in confined river systems than those faced by broader coastal populations of the same species.
Why does the Irrawaddy dolphin spit water while hunting?
This species has been observed spitting streams of water while hunting, a behaviour thought to help herd or disorient nearby fish before capture, an unusual hunting technique that adds to the species' distinctive behavioural repertoire.