The fish crow (''Corvus ossifragus'') is a species of

crow A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...

associated with

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

habitats in the eastern and southeastern United States.

Taxonomy and etymology

The fish crow was given its

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

by the Scottish

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

Alexander Wilson in 1812, in the fifth volume of his ''American Ornithology''. The binomial is from

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

; ''Corvus'' means "raven", while ''ossifragus'' means "bone-breaker". It is derived from ''os'' or ''ossis'', meaning "bone", and ''frangere'', meaning "to break". The English-language

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

''fish crow'' also derives from Wilson, who ascribed the name to the crow's aquatic diet, as described to him by local fishermen. He distinguished the fish crow from John Bartram's ''great seaside crow'' by the former's diminutive size when compared to the

American crow The American crow (''Corvus brachyrhynchos'') is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America. American crows are the New World counterpart to the carrion crow of Europe an ...

. The fish crow's taxonomic relation to other species of the ''

Corvus ''Corvus'' is a widely distributed genus of medium-sized to large birds in the family Corvidae. It includes species commonly known as crows, ravens and Rook (bird), rooks. The species commonly encountered in Europe are the carrion crow, the hoo ...

'' genus is still poorly understood, but

DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...

indicates that it is most closely related to the

palm crow The palm crow (''Corvus palmarum'') is a relatively small corvid that occurs on the Caribbean island of Hispaniola ( Haiti and the Dominican Republic) and Cuba, where it was formerly very frequent, but is now reduced in population. Taxonomy Th ...

(''C. palmarum'') and the

Jamaican crow The Jamaican crow (''Corvus jamaicensis'') is a comparatively small corvid (35–38 cm in length). It shares several key morphological features with two other West Indian species, the Cuban crow (''Corvus nasicus'') and the white-necked crow ...

(''C. jamaicensis''), with the three species forming a

Nearctic The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America t ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

. The

Sinaloa crow The Sinaloa crow (''Corvus sinaloae'') is a crow native to western Mexico. Description Visually, it is nearly identical to and the same length (34–38 cm) as the Tamaulipas crow (''Corvus imparatus''). It has the same purple-glossed, silky ...

(''C. sinaloae'') and

Tamaulipas crow The Tamaulipas crow (''Corvus imparatus'') is a crow found in northeastern Mexico and southern Texas. Description It is a relatively small and sleek looking crow, in length. It has very glossy dark, bluish plumage, which appears soft and silky ...

(''C. imparatus'') bear morphological similarities to and were once considered conspecific

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of the fish crow, but have since been recognized as distinct species.

Description

The fish crow is a small bird, with an average adult weight of in males and in females. The average male wingspan is similarly larger at , compared to in females. The total body length is between . The fish crow is superficially similar to the American crow, but is smaller and has a silkier, smoother 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 seen 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.Goodwin, p. 92 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 Begging (also panhandling) is the practice of imploring others to grant a favor, often a gift of money, with little or no expectation of reciprocation. A person doing such is called a beggar or panhandler. Beggars may operate in public place ...

"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". The fish crow also has a single call sounding like "cahrrr".

Distribution and habitat

This species occurs on the eastern seaboard of the United States from

Rhode Island Rhode Island (, like ''road'') is a U.S. state, state in the New England region of the Northeastern United States. It is the List of U.S. states by area, smallest U.S. state by area and the List of states and territories of the United States ...

south to

Key West Key West ( es, Cayo Hueso) is an island in the Straits of Florida, within the U.S. state of Florida. Together with all or parts of the separate islands of Dredgers Key, Fleming Key, Sunset Key, and the northern part of Stock Island, it cons ...

, and west along the northern coastline of the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

and follows many river systems inland for quite some distance. Coastal marshes and beaches, rivers, inland lakes and marshes, river banks, and the land immediately surrounding all are frequented.

Behavior

Diet

Food is taken mainly from the ground or shallow water where the bird hovers and plucks food items out of the water with its feet. The fish crow is omnivorous. It feeds on small

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, such as

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s and

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

s, 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.

Breeding

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. Usually, four or five eggs are laid. Pale blue-green in colour, they bear blotches of olive-brown.Goodwin, p. 93 Fish crows build a new nest for each breeding attempt. A pair of fish crows were reported to have raised a young

blue jay The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are a ...

for multiple weeks.

Conservation

This species appears to be somewhat more resistant to

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family ''Flaviviridae'', from the genus ''Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The virus ...

than the American crow. Survival rates of up to 45% have been reported for fish crows, compared with near zero for American crows.

References

External links

Differences between American and Fish CrowsFish Crow videos
from the Cornell Lab of Ornithology's Macaulay Library
Page from The Cornell Lab of Ornithology
*

Sound link

Fish crow call

Image link

{{Taxonbar, from=Q1420315

fish crow The fish crow (''Corvus ossifragus'') is a species of crow associated with wetland habitats in the eastern and southeastern United States. Taxonomy and etymology The fish crow was given its binomial name by the Scottish ornithologist Alexa ...

Native birds of the Southeastern United States Endemic birds of the Eastern United States

Taxa named by Alexander Wilson (ornithologist)