The crab-plover (Dromas ardeola) belongs to the exclusive crab-plover genus Dromas under the family Dromadidae.
The crab-plover species are distributed in the coasts and islands of the Indian Ocean, northern coast of Arabian Sea, coast of Red Sea, coast of Arabian peninsula, Persian Gulf, Andaman and Nicobar Islands, southern Myanmar and southern Thailand. These crab-plover species nest in burrows. These crab-plovers are monotypic species.
Crab-plover - Overview
- Scientific name: Dromas ardeola
- Species author: Paykull, 1805
- Synonyms/Protonym: Dromas Ardeola Paykull, 1805
- Family: Dromadidae › Charadriiformes › Aves › Chordata › Animalia
- Vernacular names: English: Crab-plover, Chinese: 蟹鸻, French: Drome ardéole, German: Reiherläufe,r Spanish: Dromas, Russian: Рачья ржанка, Japanese: カニチドリ, Tamil: Nandu Thinni
- Other names: Crab Plover
- Distribution: coasts and islands of the Indian Ocean
- Diet and feeding habits: crustaceans, small bivalve molluscs, marine worms
- IUCN status listing: Least Concern (LC)
Appearance, physical description and identification
The crab-plover (Dromas ardeola) is a medium-sized bird, measuring 35 to 40 cm in length and weighing 230 to 320 grams. The wingspan is 65 to 80 cm.The overall plumage of the crab-plover is black and white. The upperparts are white, except for black mantle, inner scapulars and primary feathers of the wings. In juveniles, the mantle is pale gray and the rear crown and nape have blackish streaks.
These crab-plovers resemble plovers in general, but have long bluish gray legs and strong black bill. In flight, the neck is extended and the legs trail behind the tail. They often rest on tarsi. They are noisy birds and their call is a harsh chattering "ka.ka.ka.ka" sound.
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| Birds of India - Image of Crab-plover - Dromas ardeola by Donald Macauley |
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| Indian birds - Picture of Crab-plover - Dromas ardeola by Koshy Koshy |
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| Birds of India - Photo of Crab-plover - Dromas ardeola by Donald Macauley |
Origin, geographical range and distribution
The crab-plover species are distributed in the coasts and islands of the Indian Ocean, northern coast of Arabian Sea, coast of Arabian peninsula, Persian Gulf, Andaman and Nicobar Islands, southern Myanmar and southern Thailand.The breeding populations of the crab-plover species occur along the coast of Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq and Iran.
In India, the wintering populations of the crab-plover species are distributed in the states of Karnataka, Kerala and Tamil Nadu. These species are also distributed in the Indian islands of Lakshadweep, Andaman and Nicobar.
The Important Bird and Biodiversity Areas (IBA) of these crab-plover species in Yemen are, Aden, Al-'Urj, Al-Mukha - Al-Khawkhah, Islands north of Al-Hudaydah and Midi - Al-Luhayyah. The IBA in United Arab Emirates are Abu al Abyadh island, Khor al Beideh and Umm Amin.
The IBA of crab-plover in Saudi Arabia are, Qishran Bay, Madinat Yanbu al-Sinaiyah, Abu Ali, Al-Wajh Bank, Farasan Islands, Khawr Wahlan and Jizan Bay. The IBA of crab-plover in Oman are Barr al Hikman and Masirah island.
The IBA of crab-plover in Iran are, Rud-i-Gaz and Rud-i-Hara deltas, Nakhilu, Morghu and Ummal Karam islands, Bahu Kalat Protected Area, Khouran Straits, Bushire Bay and Nakhilu, Morghu and Ummal Karam islands.
The IBA of crab-plover in Kenya are, Kiunga Marine National Reserve and Mida Creek, Whale Island and the Malindi - Watamu coast. The IBA of crab-plover in Kuwait are, Sulaibikhat Bay, Dawhat Kazima and Ad-Doha Nature Reserve.
Ecosystem and habitat
These crab-plover species do not normally occur in forests. These species occur in altitudes from 0 to 100 meters.The natural ecosystems of these crab-plover species include sandy islets or dunes, estuaries, intertidal rocky, sandy and shingle shoreline, exposed coral reefs, intertidal mudflats, brackish water pools, coastal marine lagoons and coastal freshwater lakes.
Diet and feeding behavior
The diet of these crab-plover species is mostly crustaceans. Crabs as well as other crustaceans, small molluscs, marine worms and other invertebrates are their primary food. They dismember the prey with powerful stabs of the bill.These crab-plovers feed singly or in groups. Sometimes, large flocks forage together on mudflats or in shallow waters during low-tide. Most of the feeding activity occur in the early morning and evening. The rest of the time they gather in high-tide roost sites.
Reproduction and breeding habits
The breeding season of these crab-plover species is from April to August. They form dense breeding colonies. The breeding sites are located in sandy islands or coastal dune systems.The crab-plovers excavate nesting burrows into the sandy substrate. The burrows are set close together in a honeycomb arrangement. The typical clutch contains one egg and occasionally two.
The nest burrow maintains the optimum temperature and the crab-plover parents may leave the nest unattended for even up to two days. The hatchlings remain in the nest for several days, being unable to walk. Both the parents take care of the young.
Migration and movement patterns
The crab-plover species are partially migratory birds.Many crab-plover populations migrate southwards during August and November and return to the breeding sites in March and April. Some of the populations reside throughout the year in the breeding sites.
Post breeding, the juvenile crab-plovers may disperse and establish in new locations within the range. They may make local movements for feeding and breeding within their range.
Conservation and survival
The global population size of the crab-plover (Dromas ardeola) has not been quantified. The overall population trend of these crab-plover species is reported to be stable. Throughout its range it is reported to be locally common. The generation length is 9.6 years. Its distribution size is about 3,400,000 sq.km.The crab-plover (Dromas ardeola) does not approach the thresholds for being Vulnerable, either under the range size criterion, or under the population trend criterion or under the population size criterion. Habitat loss and oil spills are the main threats that may endanger the survival of these crab-plover species.
IUCN and CITES status
The IUCN (International Union for Conservation of Nature) has categorized and evaluated the crab-plover species and has listed it as of "Least Concern". The CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Not Evaluated’ for the crab-plover (Dromas ardeola).| Taxonomy and scientific classification of Dromas ardeola | |
|---|---|
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Dromadidae |
| Subfamily: | - |
| Genus: | Dromas |
| Species: | D. ardeola |
| Binomial name: | Dromas ardeola |
| IUCN status listing: |
 Least Concern |
1.Crab-plover photo source: https://commons.wikimedia.org/wiki/File:Flickr_-_don_macauley_-_Dromas_ardeola_2.jpg (cropped)
Photo author: Donald Macauley | License: CC BY-SA 2.0 as on 6/16/17
2.Photo source: https://upload.wikimedia.org/wikipedia/commons/5/51/Crab_Plover_%288556846776%29.jpg (cropped)
Photo author: Koshy Koshy | License: CC BY 2.0 as on 6/16/17
3.Photo source: https://en.wikipedia.org/wiki/File:Dromas_ardeola_Kenya_1.jpg (cropped)
Photo author: Donald Macauley | License: CC BY-SA 2.0 as on 6/16/17
Current topic in Birds of India: Crab-plover - Dromas ardeola.
