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*North American and east Mexican birds belong to nominate race | *North American and east Mexican birds belong to nominate race | ||
*paler and larger-billed ''bancrofti'' occurs in western Baja California and the West Indies. | *paler and larger-billed ''bancrofti'' occurs in western Baja California and the West Indies. | ||
| − | *''gravirostris'' from Socorro is also large-billed and '' | + | *''gravirostris'' from Socorro is also large-billed and ''caliginis'' of the Pacific coast from Panama to Peru has a large bill and darker grey upperparts. |
*Remainder of South American range is occupied by ''cayennensis''. Slender-billed with dark upperparts. | *Remainder of South American range is occupied by ''cayennensis''. Slender-billed with dark upperparts. | ||
*''pauper'' from the Galapagos Islands is small and dark. | *''pauper'' from the Galapagos Islands is small and dark. | ||
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==References== | ==References== | ||
| − | #{{Ref- | + | #{{Ref-Clements6thAug14}}#Birdforum member personal observations |
==External Links== | ==External Links== | ||
{{GSearch|Nyctanassa+violacea}} | {{GSearch|Nyctanassa+violacea}} | ||
Revision as of 14:02, 16 August 2014
- Nyctanassa violacea
Identification
61 cm. Grey body, Pale yellow crown, red eyes and short yellow legs, white stripe below the eye completely surrounded by black. Black feather centers produce a pattern on the wings. The bill has a specific shape, with the culmen tapering down and the mandible tapering up to the tip of the bill so that the bill overall is shaped like a chisel. Juveniles are mainly brown flecked with white or gray.
In flight will have strong legs protruding back beyond the short tail and the neck held in a compact S shape.
Similar species
Black-crowned Night-Heron and Boat-billed Heron are the most similar to both adults and juveniles, and the juvenile additionally has some similarities to American Bittern. Notice the shape of the bill of the Black-crowned Night-Heron which has lower edge of the mandible straight.
Distribution
North, Central and South America and the Caribbean.
North America: limited to eastern parts where breeding coastally from Maine to Florida and the along the Gulf Coast and inland from the Great Lakes to Colorado and Texas.
Central America: Range continues along Gulf Coast of Mexico and along the Atlantic side south to Panama and also occurs along the Pacific coast from Baja California southwards.
South America: occurs in coastal areas from Colombia to Rio Grande do Sul, Brazil in the east, as well as south to northern Peru in the west and on the Galapagos Islands.
The Caribbean: Also occurs throughout the West Indies and has been reintroduced to Bermuda.
Most northern birds move southwards after breeding to winter in the southern USA, Mexico, Central America and the West Indies. Vagrants recorded north to Nova Scotia and Newfoundland.
Taxonomy
Six subspecies are recognised.
- North American and east Mexican birds belong to nominate race
- paler and larger-billed bancrofti occurs in western Baja California and the West Indies.
- gravirostris from Socorro is also large-billed and caliginis of the Pacific coast from Panama to Peru has a large bill and darker grey upperparts.
- Remainder of South American range is occupied by cayennensis. Slender-billed with dark upperparts.
- pauper from the Galapagos Islands is small and dark.
Habitat
Mainly coastal areas including rocky shores, mudflats and mangroves. Also inland on lakeshores and riverbanks. Breeding in swamps and marshes.
Behaviour
They often nest in colonies; the nests are platforms of sticks in trees or shrubs, often near or overhanging water. 3–5 pale blue-green eggs are laid.
The degree to which they are active during day or dawn/dusk varies both geographically and with time of year; they are more likely to be encountered before dark when they have young in the nest. The diet includes crustaceans, molluscs, frogs, aquatic insects and small fish, but one favorite food is land crabs; their bills are shaped like chisels and used to hammer a hole in the back of the crab shell.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2014. The eBird/Clements checklist of birds of the world: Version 6.9., with updates to August 2014. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Birdforum member personal observations
External Links
