The Fish Crow (Corvus ossifragus) is year-round resident locally from New York and Massachusetts south along the Atlantic-Gulf Coast to southern Florida and west to southern Texas, as well as inland along major river systems. It is very common in parts of its range. Fish Crows are found around tidewater marshes, low valleys along eastern river systems, and in Baldcypress (Taxodium) swamps; in recent decades, the interior range has expanded and the northern boundary of the range has extended northward. Although in most parts of its range it is a permanent resident, in winter Fish Crows withdraw from some parts of their inland range. In the winter, Fish Crows are often seen in mixed flocks with American Crows, when they may also be found on farmland, in towns, and around garbage dumps. The Fish Crow is one of only about a dozen bird species that are endemic to the United States (i.e., found nowhere else in the world).
The Fish Crow closely resembles the American Crow (Corvus brachyrhynchos), but is smaller overall and has a smaller bill, smaller feet, and shorter legs, as well as more pointed wings and a faster wingbeat. However, it is best distinguished by its quite different common call, a nasal two-note call with the second note lower in pitch (however, juvenile and sometimes adult American Crows produce similar calls).
Fish Crows may feed on an extraordinary range of foods, including carrion, crustaceans, insects, berries, seeds, nuts, bird eggs, turtle eggs, and human garbage. They generally forage in flocks, mainly by walking, especially along the shore or in very shallow water. They may drop mollusks from the air to break open their shells. In colonies of herons and other waterbirds, if the nesting adults are frightened off their nests, Fish Crows may feast on their eggs.
Fish Crows often nest in loose colonies of a few pairs. Courtship may involve the male and female flying close together in a gliding display flight. The nest is placed in an upright fork of a tree or shrub. The nest may be placed very low at coastal sites or quite high in deciduous trees in inland swamps (1 to 21 m above the ground or even higher) The nest (which is probably built by both sexes) is a bulky platform of sticks and strips of bark lined with softer materials such as grass,rootlets, hair, feathers, paper, pine needles, and even manure. The female lays 4 to 5 dull blue-green to gray-green eggs blotched with brown and gray. Incubation is by the female (possibly assisted by the male) for 16 to 18 days. Nestlings are probably fed by both parents. The age at which young leave the nest is uncertain, but is probably around 3 to 4 weeks.
(Kaufman 1996; AOU 1998; Dunn and Alderfer 2011)
- American Ornithologists' Union. 1998. Check-list of North American Birds, 7th edition. American Ornithologists' Union, Washington, D.C.
- Dunn, J.L. and J. Alderfer. 2011. National Geographic Field Guide to the Birds of North America. National Geographic Society, Washington, D.C.
- Kaufman, K. 1996. Lives of North American Birds. Houghton Mifflin, Boston.
Global Range: Resident from New York and Massachusetts south along Atlantic-Gulf coast to southern Florida, and west to southern Texas; inland along major river systems to northwestern Illinois, southwestern Kentucky, western Tennessee, central Georgia, western South Carolina, northwestern North Carolina, central Virginia, central Maryland, eastern West Virginia, and central Pennsylvania (AOU 1983). Range expanding inland in Carolinas and Georgia (McNair 1989).
endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, B.L. Sullivan, C. L. Wood, and D. Roberson. 2012. The eBird/Clements checklist of birds of the world: Version 6.7. Downloaded from http://www.birds.cornell.edu/clementschecklist/downloadable-clements-checklist
Length: 39 cm
Weight: 300 grams
Comments: Beaches, bays, lagoons, inlets, swamps, near marshes, and, less frequently, deciduous or coniferous woodland. In inland situations, primarily in baldcypress swamps and along major watercourses; also garbage dumps and towns (McNair 1989). Nests in tree, usually high, but sometimes as low as 2 m (Harrison 1978).
Habitat and Ecology
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: No. No populations of this species make annual migrations of over 200 km.
NGS (1983) indicated only breeding season occurrence in northern part of range in Mississippi River drainage.
Comments: Eats shoreline invertebrates, eggs of shore and sea birds and turtles, insects and other terrestrial invertebrates, various fruits and berries, carrion (Terres 1980).
Known prey organisms
This list may not be complete but is based on published studies.
Life History and Behavior
Lifespan, longevity, and ageing
Clutch size is 4-5. Incubation, apparently by both sexes, lasts 16-18 days. Young leave nest at 21 days or more. Usually nests in small colony of well-spaced pairs.
Molecular Biology and Genetics
Barcode data: Corvus ossifragus
There are 2 barcode sequences available from BOLD and GenBank. 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: Corvus ossifragus
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
IUCN Red List Assessment
Red List Category
Red List Criteria
The fish crow was first described by Alexander Wilson in 1812. The latest genetic testing now seems to indicate that this species is close to the Sinaloan crow (Corvus sinaloae) and the Tamaulipas crow (Corvus imparatus), and not as close to the American crow (Corvus brachyrhynchos) as outward signs would suggest.
The fish crow is superficially similar to the American crow but is smaller (36–41 cm in length) and has a more silky smooth plumage by comparison. The upperparts have a blue or blue-green sheen, while the underparts have a more greenish tint to the black. The eyes are dark brown. The differences are often only really apparent between the two species when side by side or, when heard calling. The bill is usually somewhat slimmer than the American crow, but is only readily distinguishable if both species are seen together.
Visual differentiation from the American crow is extremely difficult and often inaccurate. Nonetheless, differences apart from size do exist. Fish crows tend to have more slender bills and feet. There may also be a small sharp hook at the end of the upper bill. Fish crows also appear as if they have shorter legs when walking. More dramatically, when calling, fish crows tend to hunch and fluff their throat feathers.
The voice is the most outwardly differing characteristic for this species and other American crow species. The call of the fish crow has been described as a nasal "ark-ark-ark" or a begging "waw-waw". Birders often distinguish the two species (in areas where their range overlaps) with the mnemonic aid "Just ask him if he is an American crow. If he says "no", he is a fish crow." referring to the fact that the most common call of the American crow is a distinct "caw caw", while that of the fish crow is a nasal "nyuh unh".
Distribution and habitat
This species occurs on the eastern seaboard of the United States from the state of Rhode Island south to Key West, and west along the northern coastline of the Gulf of Mexico and follows many river systems inland for quite some distance. Coastal marshes and beaches are frequented, also rivers, inland lakes and marshes, river banks, and the land immediately surrounding all.
Food is taken mainly from the ground and even in shallow water where the bird will hover and pluck food items out of the water with its feet. The fish crow is omnivorous. It will feed on small crustaceans, such as crabs and shrimps, other invertebrates, stranded fish and live fish if the situation favors their capture, eggs and nestlings of birds, small reptiles, the fruits of many trees, peanuts and grains, as well as human scraps where available.
The nest is usually built high in a tree and is often accompanied in nearby trees with other nests of the same species forming small, loose colonies. There are usually 4-5 eggs laid. Pale blue-green in colour, they bear blotches of olive-brown.
This species appears to be somewhat more resistant to West Nile virus than the American crow. Survival rates of up to 45% have been reported for fish crows, compared with near zero for the American species.
- BirdLife International (2012). "Corvus ossifragus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- Goodwin, p. 92
- Cornell Lab of Ornithology, Fish Crow - Physical Characters
- Cornell Lab of Ornithology, Fish Crow - Voice
- Goodwin, p. 93
- "West Nile and Ravens". Rhode Island Department of Environmental Management. Retrieved 28 April 2014.
Names and Taxonomy
Comments: Considered conspecific with C. IMPARATUS by some authors (AOU 1983). May or may not constitute a superspecies with C. SINALOAE, C. IMPARATUS, and C. PALMARUM (AOU 1998).