Orcaella brevirostris | Red List of Bangladesh Volume 2: Mammals

Taxa
Orcaella brevirostris | (Owen in Gray, 1866)
Orcaella brevirostris | (Owen, 1866)
Publication
Red List of Bangladesh Volume 2: Mammals
NRL Record ID
327625
Location
Countries in Assessment
Bangladesh
Country ISO code(s)
BGD
Does the assessment cover a marine EEZ area(s)?
Off
Scope (Assessment)
National
Taxon
Common Names
Irrawaddy Dolphin
Iraboti
Hiraboti
Shushuk
Shush
Hush
Hochchum
RRL Synonyms
Orca (Orcaella) brevirostris Owen, 1866; Orcaella brevirostris brevirostris Ellerman & Morrison-Scott, 1951; Orcaella brevirostris fluminalis Ellerman & Morrison-Scott, 1951; Orcaella fluminalis Gray, 1871; Orcella brevirostris Anderson, 1871; Orcella flu
Taxonomic Group
Vertebrates
Taxonomic Group Level 2
Mammals
Assessed taxon level
Species
Taxonomic Notes
Dolphins of the genus Orcaella were recently split into two species, the Irrawaddy Dolphin Orcaella brevirostris and the Snub-fin Dolphin O. heinsohni (Beasley et al. 2002, 2005) as quoted in Reeves et al. 2008. Of these, Orcaella brevirostris occurs in B
Taxon distribution as listed in assessment
Reeves et al. 2008 described its distribution in warm coastal waters and rivers from the Bay of Bengal to western Sulawesi, Indonesia. It occurs in Bangladesh, Brunei Darussalam, Cambodia, India, Indonesia, Lao PDR, Malaysia, Myanmar, Philippines, Singapore, Thailand, Viet Nam (Reeves et al. 2008). Waterways of the Sundarbans mangrove forest and fresh water affected coastal waters in the Bay of Bengal.
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
No
Habitat
Habitat details as listed in assessment
It generally occurrs in small group of 1-6 animals in the Sundarbans and 1-10 animals in the coastal water, and they are very social. Inconspicuous surfacing, only show part of the back. Leaps are infrequent. Average dive duration is 115.3 second. Turbid fresh and brackish waters in the waterways of the Sundarbans and freshwater affected coastal waters in the Bay of Bengal. They prefer water depth from 2.7-16.0 meter and salinity from 7.0-34.0 ppt (Smith et al. 2008).
Is there a map available in assessment?
Yes, in the publication/on website
Assessed status
Asessment status in full
Near Threatened
Assessment status abreviation
NT
Assessment rationale/justification
The species is mostly found in freshwater affected coastal waters and waterways of the Sundarbans in a large range. The Extent of Occurrence and the Area of Occupancy of this species is much higher than the threshold level. The population size is 451 individuals (3.4% calves) in the Sundarbans (Smith et al. 2006) and 5,383 individuals in coastal waters in the Bay of Bengal (Smith et al. 2008). It does not fulfill any of the criteria to qualify threatened categories but based on its existing threats, it has been categorized as Near Threatened.
About the assessment
Assessment year
2015
Assessors/contributors/reviewers listed
Md. Zahangir Alom
Affliation of assessor(s)/contributors/reviewers listed on assessment
NGO
Academic
Assessor affiliation specific
Academic|NGO
Criteria system
Criteria system specifics
IUCN v3.1 + Regional Guidelines v4.0
Criteria system used
IUCN
Criteria Citation
IUCN (2012) IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp; IUCN (2012) Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
URL (link) of redlist assessment or publication
http://iucnredlistbd.org/
Endemism
Endemic to region
No
Endemism Notes
Is an endemic?: No
Conservation
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Further information
History
Critically Endangered in Bangladesh (IUCN Bangladesh 2000).
Scientific Name Kingdom Phylum Class Order Family Genus
Orcaella brevirostris Animalia Chordata Mammalia Cetartiodactyla Delphinidae Orcaella
Orcaella brevirostris Animalia Chordata Mammalia Cetacea Delphinidae Orcaella