The oriental dollarbird (Eurystomus orientalis), also known as dollar roller, belongs to the family of rollers, Coraciidae.
These dollarbird species are distributed in Indian subcontinent, Southeast Asia, Indochina region, China, Russia, Japan, Indonesia, Australia and Philippines. The oriental dollarbird species have highly visible, light blue patches on the outer parts of the wings and hence the name. There are ten recognized subspecies of dollarbirds.
Oriental dollarbird - Overview
- Scientific name: Eurystomus orientalis
- Species author: (Linnaeus, 1766)
- Synonyms/Protonym: Coracias orientalis Linnaeus, 1766, Eurystomus solomonensis
- Family: Coraciidae › Coraciiformes › Aves › Chordata › Animalia
- Vernacular names: English:Oriental dollarbird, Chinese: 三宝鸟, French: Rolle oriental, German: Türkisracke, Spanish: Carraca oriental, Russian: Широкорот, Japanese: ブッポウソウ, Indonesian: Holo-holo, Malay: urung Tiong Batu
- Other names: Dollarbird, Asian Dollarbird, Broad-billed Roller, Dark Roller, dollar roller
- Distribution: India, Nepal, Bangladesh, Bhutan, China, Japan, North Korea, South Korea, Russia, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Singapore, Brunei, Indonesia, Australia, Philippines, Papua New Guinea, Timor-Leste
- Diet and feeding habits: beetles, moths, crickets, grasshoppers, cicadas, wasps
- IUCN status listing: Least Concern (LC)
The ten recognized subspecies of oriental dollarbird are: E. o. pacificus (Latham, 1801), E. o. solomonensis Sharpe, 1890, E. o. crassirostris P. L. Sclater, 1869, E. o. waigiouensis Elliot, 1871, E. o. oberholseri Junge, 1936, E. o. gigas Stresemann, 1913, E. o. irisi Deraniyagala, 1950, E. o. laetior Sharpe, 1890, E. o. orientalis (Linnaeus, 1766) and E. o. calonyx Sharpe, 1890.
Appearance, physical description and identification
The oriental dollarbird (Eurystomus orientalis) is a medium sized roller, measuring 25 to 30 cm in length and weighing 110 to 190 grams in weight.The bill of dollarbird is short and wide. In adults, it is reddish orange with a curved black tip. In juveniles, the bill is brownish orange. The feet are reddish in adults and brownish orange in immature birds. In oriental dollarbird juveniles, the throat region is whitish. The irises are black. The females are slightly duller in color. Their call is an occasional repeated short, hoarse “rak” sound.
Birds of India - Picture of Oriental dollarbird - Eurystomus orientalis by N. A. Naseer |
Indian birds - Photo of Oriental dollarbird - Eurystomus orientalis by N. A. Naseer |
Birds of India - Picture of Oriental dollarbird - Eurystomus orientalis by Lip Kee |
Origin, geographical range and distribution
These oriental dollarbird species are distributed in India, Nepal, Bangladesh, Bhutan, China, Japan, North Korea, South Korea, Russia, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Singapore, Brunei, Indonesia, Australia, Philippines, Papua New Guinea and Timor-Leste.The dollarbird subspecies E. o. calonyx is distributed in north and northeast India, Nepal, Bangladesh, East China, Far east Russia, Korea and Japan. It migrates to southern India, southeastern Asia and Indonesia for wintering. The subspecies E. o. oberholseri is distributed in Simeulue Island (Indonesia).
The oriental dollarbird subspecies E. o. pacificus is distributed in Lesser Sundas, South Sulawesi and Sula Islands and Australia. The southern populations move to New Guinea and nearby islands for wintering. The dollarbird subspecies E. o. laetior is distributed in Western Ghats and Kerala in southwestern India. The subspecies E. o. irisi is distributed in Sri Lanka.
The dollarbird subspecies E. o. orientalis is distributed in northeastern India, southeastern Asia, Indochina, Ryukyu Islands, Philippines and Indonesia. They winter in southern India, Philippines and Sulawesi and Moluccas Islands of Indonesia. The subspecies E. o. gigas is distributed in South Andaman Islands.
The oriental dollarbird subspecies E. o. waigiouensis is distributed in Papuan Island and New Guinea. The subspecies E. o. crassirostris is distributed in Bismarck Archipelago. The subspecies E. o. solomonensis is distributed in Feni Islands (Papua New Guinea) and Solomon Islands
Ecosystem and habitat
These oriental dollarbird species are moderately forest dependent. They inhabit various artificial and natural ecosystems. They inhabit plantations, farmlands, pasturelands, rural and urban gardens and parks. They are found in tropical and subtropical moist lowland forests, tropical and subtropical moist montane forests, tropical and subtropical moist shrublands and submontane forests. The oriental dollarbirds occur in altitudes from 0 to 1500 meters.Diet and feeding behavior
The diet of these dollarbird species is mostly flying insects. Insects like grasshoppers, locusts, cicadas, moths, butterflies, airborne spiders, beetles and wasps are the primary food. They perch on a bare branch of a tree and 'hawk' flying insects and return to the same perch for eating. The oriental dollarbird may occasionally feed on insects on the ground.Reproduction and breeding habits
The breeding season of these oriental dollarbird species is from September to April in Australia. The breeding season is from March to May in India and in May and June in Japan. They nest in tree cavities, rock crevices and abandoned woodpecker holes. The oriental dollarbird species lay eggs in these unlined nests and both parents incubate the eggs and take care of the hatchlings.Migration and movement patterns
These oriental dollarbird species are mostly migratory birds. The breeding populations in Russia, China Japan move to Southeast Asian countries for wintering.Conservation and survival
The global population size of the oriental dollarbird (Eurystomus orientalis) is not quantified. The overall population size of these species is considered to be on the decline. Throughout its ranges the oriental dollarbird is reported to be common. The generation length is 5.6 years.The oriental dollarbird (Eurystomus orientalis) 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 is the main threat to the survival of these dollarbird species.
IUCN and CITES status
The IUCN (International Union for Conservation of Nature) has categorized and evaluated the dollarbird species and has listed it as of "Least Concern". CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Not Evaluated’ for the oriental dollarbird (Eurystomus orientalis).1.Image source: https://commons.wikimedia.org/wiki/File:Dollarbird_by_N.A._Nazeer.jpg
Image author: N. A. Naseer / www.nilgirimarten.com | License: CC BY-SA 2.5 IN
2.Image source: https://commons.wikimedia.org/wiki/File:Dollarbird_by_N.A._Nazeer.jpg
Image author: N. A. Naseer / www.nilgirimarten.com | License: CC BY-SA 2.5 IN
3.Image source: https://www.flickr.com/photos/lipkee/469867125/
Image author: Lip Kee | License: CC BY-SA 2.0 (as on 2016-12-21)
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