Irrawaddy dolphins can be found in some coastal areas in Asia but there are only three freshwater sub-populations. These are found in the Irrawaddy River Myanmar, the Mahakam River Indonesia, and the Mekong River in Cambodia - Laos PDR.
Irrawaddy dolphins (Orcaella-brevirostris) are quite shy, and all that can be seen of them most of the time is a dorsal fin or a tail fluke. They are believed to give birth to a single calf every two to three years, after a gestation period of 14 months. A newborn is said to be 1m long, weighing about 10kgs.
The Irrawaddy dolphin is typically slow-moving however, they can reach speeds of up to 25 miles per hour when threatened or startled and while they aren’t known for being particularly acrobatic, they have been known to breach out of the water.
Not much is known about the hunting methods of this species but it is known that their diet consists of fish, cephalopods, crustaceans and fish eggs.
In terms of appearance they share features that are visually similar to the Beluga whale although they are genetically more closely related to killer whales.
These dolphins are a gray to dark blue color with a lighter colored underbelly. They have a large forehead and rounded skull which lacks the appearance of a snout or beak. The dorsal fin is rounded and located around the middle of its back. They also have long-broad flippers and can weigh up to 300 pounds and grow to 7 – 8 feet in length.
These dolphins communicate using a series of clicks and buzzing sounds. In most cases they prefer to travel in small pods consisting of 3 – 6 dolphins although their pod size may increase to include 15 on occasion.
Generally when in search of food they will dive for 1 – 2 minutes, however they have been observed holding their breath for up to several minutes when necessary. When they need to surface for air they keep along body-profile, only exposing the top of their head and their blowhole.
Not much is known about the breeding habits of these dolphins. It is believed that mating season occurs from the beginning of the year through June.
The World Wildlife Fund (WWF) has undertaken numerous studies and overseas many education and research projects;
http://wwf.panda.org/what_we_do/endangered_species/cetaceans/about/irrawaddy_dolphin/
During your Irrawaddy Voyages journey, there is a likelihood of spotting these dolphins when cruising around the waters of Mandalay. Sightings are most common when the water levels are xxxx during the xxxx season.
Irrawaddy Dolphin Insights: