A small (22-28 inches), thick-set heron, the Yellow-crowned Night-Heron is most easily identified by its gray body, black face with white cheek patch, and conspicuous yellow crown. Where their ranges overlap, this species may be distinguished from its relative, the Black-crowned Night Heron (Nycticorax nycticorax), by the latter species’ pale face, pale breast, and, logically, by its black crown. Male and female Yellow-crowned Night-Herons are similar in all seasons. The Yellow-crowned Night Heron breeds in the eastern and southeastern United States south to Brazil. In winter, populations breeding in northern and interior portions of this species’ range migrate south to the coasts and the tropics. Coastal-breeding populations, as well as those breeding in the tropics, are non-migratory. Yellow-crowned Night-Herons inhabit a variety of wetland habitats, whether flowing or standing, large or small, and freshwater or saltwater. In tropical areas, this species may be found in mangrove wetlands and lagoons. Unlike the Black-crowned Night-Heron, the Yellow-crowned Night Heron specializes in eating crustaceans, especially crabs. Yellow-crowned Night-Herons may be best observed wading in shallow water, where they may be seen plunging their bills into the water to catch crabs. It is also possible to see Yellow-crowned Night Herons at their small nesting colonies, especially when they return to roost, or while flying with their feet extended and their necks pulled in. As its name suggests, this species hunts mainly from sunset to sunrise, although individuals may be seen during the morning and afternoon as well.
The Yellow-crowned Night-Heron ia a small, stocky (but relatively long-necked), mainly nocturnal heron. It typically forages in shallow water, feeding largely on crabs, and roosts during the day in trees or marshes (Sibley 2000). It is more solitary and often more secretive than the somewhat similar and often co-occurring Black-crowned Night-Heron (Nycticorax nycticorax) (Kaufman 1996).
occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: central Baja California, central Sonora, central and northeastern Texas, Oklahoma, northeastern Kansas, southeastern Minnesota, southern Michigan, and Massachusetts south along both coasts of Mexico to northwestern Peru and eastern Brazil, Galapagos, Bahamas, and Antilles. NORTHERN WINTER: north to central Baja California, central Sonora, Gulf Coast, and South Carolina (rarely Virginia). In the U.S., highest winter densities are in southwestern Florida (Root 1988).
The Yellow-crowned Night-Heron breeds from central Baja California (both slopes), central Sonora, central and northeastern Texas, central Oklahoma, east-central Colorado (rarely), Kansas, southeastern Nebraska, southern and eastern Iowa, southeastern Minnesota, southern Wisconsin, southern Michigan, the lower Ohio Valley, eastern Tennessees, southeastern Pennsylvania, Massachusetts and southern Maine (rarely) south along both slopes of Mexico, the Gulf coast, Bahamas, Antilles, Middle America (including Socorro Island in the Revillagigedo Islands and Isla Maria Madre in the Tres Mafias Islands), and South America (including the Galapagos Islands) on the Pacific coast to extreme northern Peru and on the Caribbean-Atlantic coast to eastern Brazil (A.O.U. 1998).
It winters from central Baja California, central Sonora, the Gulf coast (locally), and coastal South Carolina south throughout the remainder of the breeding range (A.O.U. 1998).
The Yellow-crowned Night-Heron was introduced to Bermuda, where it was formerly considered casual, in the 1970s and has been breeding there since 1979 (A.O.U. 1998).
The Yellow-crowned Night-Heron wanders, at least casually, north as far as central California, southern Arizona, southern New Mexico, Montana, North Dakota, southern Saskatchewan, southern Manitoba, southern Ontario, southern Quebec, southern New Brunswick, Newfoundland, and Nova Scotia, and to Clipperton Island (A.O.U. 1998).
Length: 61 cm
Weight: 716 grams
Adult differs from adult black-crowned night-heron in having a buffy-white crown (vs. black) and a gray back that does not contrast with the upper wing surface (vs. contrasting black back). Juvenile differs from juvenile black-crowned night-heron in having grayer upperparts with less prominent white spots and streaks, a thinner neck, and a thicker all-dark bill (vs. mostly yellow lower mandible). All ages differ from black-crowned night-heron in having longer legs that, in flight, extend well beyond the end of the tail. Differs from American bittern in having a thicker bill and in lacking flight feathers that are much darker than the back. Lacks the contrasting buffy patches on the upper-wing surface of the much smaller (length 33 cm) least bittern. Has a much thicker bill and a longer neck than does the smaller (length 46 cm) green heron.
Based on Dunn and Alderfer 2006: The easy-to-recognize adult Yellow-crowned Night-Heron has a buffy white crown and a black face with white cheeks. In the breeding season, it acquires several long buffy white head plumes that extend down behind its neck. The white-spotted brown plumaged juveniles closely resemble juvenile Black-crowned Night-Herons (Nycticorax nycticorax). Yellow-crowned juveniles can be distinguished by their somewhat grayer upperparts with less conspicuous white spotting; longer neck; stouter, mostly dark bill; and larger eyes. In flight, the Yellow-crowned shows darker flight feathers and trailing edge of the wing and the legs extend farther beyond the tail. For both the Yellow-crowned and Black-crowned Night-Herons, full adult plumage is not acquired until the third year.
Habitat and Ecology
Comments: Marshes, swamps, lakes, lagoons, and mangroves; chiefly coastal. Mostly in large cypress swamps in Louisiana, in mangroves in Florida. Prefers mangroves and gallery forest for roosting (Costa Rica, Stiles and Skutch 1989). Nests in trees in wooded situations near water, occasionally in arid scrub on islands; sometimes on ground. Along U.S. Gulf Coast from Alabama to Texas, seems to prefer inland freshwater habitats and riverine swamps for nesting (Spendelow and Patton 1988). Nested 8-23 m up in loblolly pines in Virginia, 20-1100 m from water, primarily in highly populated residential areas (Watts 1989).
The Yellow-crowned Night-Heron favors wooded wetlands, especially swamps, lakes, lagoons, and mangroves; it sometimes nests in wooded suburbs (A.O.U. 1998). It also commonly occurs in shallow tidal waters, as well as along lowland rivers with trees or other heavy cover nearby; it is rarely found in open marshes (Kaufman 1996).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Most have departed from the mid-Atlantic coast of the U.S. by mid- to late September (Byrd and Johnston 1991).
Over much of its extensive distribution, the Yellow-crowned Night-Heron is fairly sedentary (Martinez-Vilalta and Motis1992). In the United States, it may be a permanent resident in southern Florida, but over most of its range in the U.S. it is far less common in winter than in summer, with some birds traveling as far south as Panama and the Lesser Antilles (Kaufman 1996).
Comments: Eats mostly crayfishes and crabs, also other small aquatic animals (Terres 1980); feeds exclusively on crustaceans in the eastern and southern U.S. (Riegner 1982). Forages in shallows or among marsh vegetation, along seashore, on mudflats, in salt ponds, sometimes along river and pond margins (Stiles and Skutch 1989).
The diet of the Yellow-crowned Night-Heron includes many crustaceans, especially crabs and crayfish, particularly in coastal areas. It also eats mollusks, frogs, fishes, and insects (Kaufman 1996).
The Yellow-crowned Night-Heron (or a close now-extinct relative) was resident in Bermuda prior to human settlement, but was subsequently largely absent for hundreds of years. In the late 1970s, Yellow-crowned Night-Herons were re-introduced from Florida in an effort to control populations of the land crab Gecarcinus lateralis, which is widely regarded as a pest in Bermuda. A resident breeding population was successfully established and does consume large numbers of the crabs. Subsequent to this heron's establishment on Bermuda, examination of regurgitated pellets confirmed that land crabs comprised approximately 95% of its diet, even in winter, and a reduction of crab holes occurred on lawns and pathways in areas where the birds fed regularly (Wingate 1982).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Usually solitary but sometimes small groups may forage in a limited area.
Life History and Behavior
The Yellow-crowned Night-Heron feeds mainly at dusk and at night (hence the common name). Although it may also forage during the day, particularly in coastal areas (Kaufman 1996), it is more strictly nocturnal than the sympatric (co-occurring) Black-crowned Night-Heron (Nycticorax nycticorax) and typically spends the day roosting quietly in trees or marshes (Sibley 2000).
Where common, this species may nest in colonies, sometimes with Black-crowned Night-Herons and other herons. The nest is a platform of sticks, often constructed in a tree high above the water, but sometimes low in thickets or mangoves (Kaufman 1996; Martinez-Vilalta and Motis1992).
Comments: Primarily nocturnal/crepuscular but also commonly active during daylight, especially where tidal changes determine food availability.
Egg laying occurs mainly March-May in Florida, March-June in Louisiana, and April-May farther north. Clutch size usually is 2-5. Incubation, by both sexes, lasts about 27 days. Adults care for young for about 37 days; young may return to the nest site to roost for a few weeks after fledging. Single-brooded, but may lay replacement clutches. May nest in large single-species colony in some areas, but single pairs or small scattered groups on edges of other dense heronries are common (Spendelow and Patton 1988).
Eggs 4-5 (sometimes 2-8), pale blue-green; incubation (21-25 days) and feeding are carried out by both parents (Kaufman 1996). Age at first flight is about 6 weeks (Kaufman 1996).
Evolution and Systematics
Systematics and Taxonomy
The Yellow-crowned Night-Heron was still included in the genus Nycticorax in the 6th edition of the American Ornithologists' Union's Check-list of North American Birds (1983), but based on new research was subsequently moved to the monotypic (i.e, containing just a single species) genus Nyctanassa (A .O.U. 1989: 533).
Molecular Biology and Genetics
Barcode data: Nyctanassa violacea
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Nyctanassa violacea
Public Records: 3
Specimens with Barcodes: 4
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Common in many portions of the large range, but trends are unknown for many regions.
At least in North America, Yellow-crowned Night-Heron populations appear to be stable, and in some areas the breeding range has been expanding northward (Kaufman 1996).
Comments: Threats include disturbance and loss/degradation of nesting and foraging habitat. Probably susceptible to reduced reproductive success caused by pesticide contamination.
Yellow-crowned night heron
The yellow-crowned night heron (Nyctanassa violacea, formerly placed in the genus Nycticorax), also called the American night heron or squawk, is a fairly small heron. It is found throughout a large part of the Americas, especially (but not exclusively) in warmer coastal regions; an example occurrence is the Petenes mangroves of the Yucatan.
Adults are about 61 cm (24 in) long and weigh 625 g (22.0 oz). They have a white crown and back with the remainder of the body grayish, red eyes and short yellow legs. They have a white stripe below the eye. Juveniles resemble young black-crowned night-herons, being mainly brown flecked with white or gray.
In warmer locations, some are permanent residents; others migrate to Central America and the West Indies. They may occasionally wander north to the lower Great Lakes or Ontario after the breeding season.
Their breeding habitat is swamps and marshes from the eastern United States to north-eastern South America. They often nest in colonies, usually on platforms of sticks in trees or shrubs. They lay 3–5 pale blue-green eggs.
Referred to as gros bec (from the French meaning thick-billed), or commonly referred to as night heron, the birds were eaten as a form of game in Cajun cuisine. Poachers sometimes raided nests for the breast meat of young birds, a practice that could destroy an entire rookery. Ibis (bec croche) was also eaten. Killing these wild birds is now illegal.
- World Wildlife Fund. 2010. Petenes mangroves. eds. Mark McGinley, C.Michael Hogan & C. Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC
- Stiles and Skutch. A guide to the birds of Costa Rica. ISBN 0-8014-9600-4
|Wikimedia Commons has media related to Nyctanassa violacea.|
|Wikispecies has information related to: Nyctanassa violacea|
- Bermuda Online: Bermudian Fauna.
- Field Guide Page on Flickr
- Stamps at bird-stamps.org (with Range Map)
- Yellow-crowned night heron videos, photos, and sounds at the Internet Bird Collection
- Yellow-crowned night heron photo gallery at VIREO (Drexel University)
- Yellow-crowned night heron species account at NeotropicalBirds (Cornell University)
Names and Taxonomy
Comments: Placed by some authors in genus Nycticorax; transferred to Nyctanassa by AOU (1989). DNA-DNA hybridization data support maintenance of Nyctanassa as distinct from Nycticorax (Sheldon, 1987, Auk 104:97-108).