Although anhingas resemble cormorants (Phalacrocorax species), the two have several differences. Cormorants are more powerful swimmers and thus able to hunt faster-swimming fish, whereas anhingas are much slower in the water and hunt slower-swimming fish. Anhingas are able to soar, but require gliding flights from trees in order to start flight, unlike cormorants, which are not able to soar and can easily take off from the water. Anhinga distributions are more limited by temperature due to their low metabolic rate. Cormorants are able to maintain higher body temperatures and are found in colder regions of North America. Also, anhingas use a flap and glide form of flight, whereas cormorants continually flap.
Normally quiet birds, vocalizations include clicks, rattles, croaks, and grunts. Anhingas typically call while on or near the nest, and occasionally while flying or perching. They are particularly silent and elusive when flightless due to molting.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
In the Americas, anhingas are abundant, although their aquatic habitats are threatened. DDT was found to have an effect on the reproductive success of these birds and banning of this pesticide in North America has benefited those birds that breed in the southern United States.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
In North America, anhingas have no particular economic impact, particularly since they do not eat the fish that humans might.
Anhingas and their eggs are eaten by humans in parts of Asia.
Positive Impacts: food
Anhingas prey primarily on fish (Percidae, Centrarchidae, Peociliidae, Cyprinodontidae), but their diet can also include aquatic invertebrates and insects. Although not particularly fast swimmers, they are effective aquatic hunters, relying on their quick necks and sharp bills to catch prey. They target slower-moving species of fish and stalk them underwater, finally striking out with their long neck and spearing the prey with the beak. They then bring the prey above water and manipulate it in order to swallow the fish head first.
Animal Foods: fish; insects; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
The northernmost distribution of Anhinga anhinga leucogaster is in the United States from North Carolina to Texas. It has however been spotted as far north as Wisconsin. Its range also includes Mexico, Central America, Panama, and Cuba. The individuals found in the more northern areas of the U.S. migrate there in March and April and stay until October, then return to Mexico and more southern parts of the U.S. Anhinga anhinga anhinga is found in South America from Colombia to Ecuador, east of the Andes to Argentina, and in Trinidad and Tobago. The range is limited by cool temperatures and low amounts of sunshine.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Anhinga anhinga prefers freshwater and coastal aquatic habitats that include shrub or tree-covered islands or shores; these habitats include lakes, marshes, swamps, mangrove swamps, shallow coastal bays, and lagoons. Within such habitats, anhingas are able to stalk slow-moving prey and seek refuge from danger in the water, and perch and sun itself in the treetops.
Aquatic Biomes: lakes and ponds; rivers and streams; coastal
Other Habitat Features: riparian ; estuarine
Range lifespan
Status: wild: 16.4 (high) years.
Average lifespan
Status: wild: 143 months.
Anhingas have an average body length of 85 cm, weight of 1350 g, wingspan of 117 cm, and bill length of 81 mm. The head is small and appears to be merely an extension of its long snake-like neck. In the neck, the 8th and 9th cervical vertebrae create a hinge-like apparatus that allows the quick catching of prey. The long, sharp, serrated bill also aids it in hunting. The wings are broad, allowing it to soar, and the feet are webbed to facilitate swimming. The physical structure of the legs is, however, more suited to crawling out of water onto land and for climbing bushes and trees. The tail is long and is used for providing lift, steering, braking, and balancing. When spread in flight, the tail resembles that of a turkey. The overall body shape of anhingas resembles that of a cormorant; the hunting action of the head and neck is more similar to a heron.
Anhingas are sexually dimorphic; males have brighter colors than females. Males have greenish-black plumage overall, accentuated by silver-gray feathers on the upper back and wings that are edged with long white plumes. They also have black crests. Females are brown with a lighter brown head and neck; juveniles are a uniform brown color. Molting of all flight feathers at the same time render them flightless for a while. Unlike some aquatic birds, all of the body feathers become completely wet upon contact with the water, allowing them to dive through the water more easily. This feature, however, causes them to have little buoyancy, to lose heat quickly, and hinders flight.
Average mass: 1350 g.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently
Average mass: 1080 g.
Average basal metabolic rate: 3.2258 W.
Anhingas are monogamous and pairs may reuse nests from year to year. The male begins courtship by soaring and gliding, followed by marking a possible nest location with leafy twigs. Then he performs behavioral displays to attract the female. Once the pair is formed, the male gathers nesting material, while the female builds a platform nest, which is usually on a branch overhanging water or in open areas in the tops of trees. The female constructs the nest by weaving sticks together and padding it with live twigs and green leaves. Usually, the highly territorial males defend any threats to nesting territories with extensive displays and even fighting. If another male approaches the territory, the resident male spreads its wings and snaps its beak. If no retreat occurs, fighting will commence by pecking at each other's heads and necks. Females are less aggressive, but will defend the nest if necessary.
Mating System: monogamous
Anhingas are believed to reach sexual maturity around two years of age. Breeding occurs seasonally in North America. In sub-tropical or tropical latitudes, breeding can occur throughout the year, or be triggered by wet or dry seasons. The female lays one egg every one to three days, until she has a clutch anywhere from two to six eggs. Average clutch size is four eggs. The oval-shaped eggs are bluish-white or pale green, sometimes occurring with brown speckles.
Breeding season: Anhingas may breed seasonally or throughout the year, depending on latitude.
Average eggs per season: 4.
Range time to hatching: 25 to 30 days.
Average fledging age: 6 weeks.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
The parents share in incubating the eggs for 25 to 30 days. In Mexico, anhingas were documented as performing particular displays when males and females switch incubating duties at the nest. These displays included two parents vocalizing to one another, and the incubating bird neck-stretching toward the mate. After the birds intertwined necks and the returning bird passed nesting material to the incubating bird, the two switched places. Upon hatching, anhinga chicks are naked and helpless. They eventually grow a white down on their belly side and a dark down on their back side. At first the parents feed the chicks by dripping fluid and regurgitated material from partially digested fish down their throats. As the chicks grow older, they shove their heads down the parents' beaks to get this food material. The chicks are in the nest approximately three weeks, but if threatened, are able to drop into the water and swim away, later climbing out of the water and back into the nest. At the end of three weeks, they are able to climb out of the nest to a branch, and fledge at approximately six weeks. They stay with their parents for several more weeks before becoming independent.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Protecting: Male, Female)
The anhinga (/ænˈhɪŋɡə/; Anhinga anhinga), sometimes called snakebird, darter, American darter, or water turkey, is a water bird of the warmer parts of the Americas. The word anhinga comes from a'ñinga in the Brazilian Tupi language and means "devil bird" or "snake bird".[2] The origin of the name is apparent when swimming: only the neck appears above water so the bird looks like a snake ready to strike. They do not have external nares (nostrils) and breathe solely through their epiglottis.
The anhinga is placed in the darter family, Anhingidae, and is closely related to Indian (Anhinga melanogaster), African (Anhinga rufa), and Australian (Anhinga novaehollandiae) darters. Like other darters, the anhinga hunts by spearing fish and other small prey using its sharp, slender beak.
Anhinga species are found all over the world in warm shallow waters.[3] The American anhinga has been subdivided into two subspecies, A. a. anhinga and A. a. leucogaster, based on their location. A. a. anhinga can be found mainly east of the Andes in South America and also the islands of Trinidad and Tobago. A. a. leucogaster can be found in the southern United States, Mexico, Cuba, and Grenada.[4] A fossil species Anhinga walterbolesi has been described from the Late Oligocene to Early Miocene of Australia.
Only birds that live in the extreme north and south of their range migrate and do so based on temperature and available sunlight. Anhingas will migrate towards the equator during winter but this range is "determined by the amount of sunshine to warm the chilled birds".[3] Although not in their usual range, anhingas have been found as far north as the states of Pennsylvania[5] and Wisconsin[6] in the United States.
Kettles of anhingas often migrate with other birds and have been described as resembling black paper gliders.[7]
The anhinga is a large bird, measuring approximately 89 cm (35 in) in length (with a range of 75–95 cm (30–37 in)), with a 1.14 m (3.7 ft) wingspan.[8][9] The A. a. anhinga subspecies is larger than A. a. leucogaster and has broader buffy tail tips.[4] They weigh on average around 1.22 kg (2.7 lb), with a range of 1.04–1.35 kg (2.3–3.0 lb).[9][10][11] The bill is relatively long (about twice the length of the head), sharply pointed, and yellow, and the webbed feet are yellow as well.[6][12][8][10]
The male is a glossy black-green with the wings, base of wings, and tail a glossy black-blue.[12] The tip of the tail is white.[13] The back of the head and the neck have elongated feathers that have been described as gray[14] or light purple-white.[12] The upper back of the body and wings is spotted or streaked with white.[14]
The female anhinga is similar to the male except that it has a pale gray-buff[15] or light brown[16] head, neck, and upper chest. The lower chest or breast is a chestnut color, and the back is browner than that of the male.[17]
The hatchling starts out bald but gains tan down within a few days of hatching. Within two weeks the tan down is replaced by white down. Three weeks after hatching, the first juvenile feathers appear. Juveniles are mostly brown until they first breed usually after the second or third winter.[3]
This bird is often mistaken for the double-crested cormorant due to its similar size and shape, although the two species can be differentiated by their tails and bills. The tail of the anhinga is wider and much longer than that of the cormorant. The bill of the anhinga is pointed, while the bill of the cormorant has a hook-tip.[18]
Anhingas swim with their webbed feet and pursue their prey, fish, under water and spear their prey by rapidly stretching out their neck. They come up to handle and swallow fish.[19] Unlike ducks, ospreys and pelicans which coat their feathers with oil from their uropygial gland, the anhinga does not have waterproof feathers. Their feathers get soaked upon immersion in water. Therefore, they cannot stay floating on water for long periods of time. Their dense bones, wetted plumage and neutral buoyancy in water, allows them to fully submerge and search for underwater prey.[20]
The anhinga cannot fly any extended distances with wet feathers. If it attempts to fly while its wings are wet, the anhinga has difficulty, flapping vigorously while "running" on the water for a short distance, often to avoid any perceived threats. Like cormorants, the anhinga stands with wings spread and feathers fanned open in a semicircular shape, facing away from the sun, to dry its feathers and absorb heat.[21] Anhingas lose body heat relatively fast and their posture helps them absorb solar radiation from the sun to counter this.[21] Because an anhinga in the drying position resembles a male turkey, it has been colloquially referred to as the 'water turkey' or 'swamp turkey'.
Anhingas feed on moderately sized wetland fishes,[9] amphibians,[22] aquatic invertebrates and insects.[23] In Alabama, the anhinga's diet consists of fishes (such as mullet, sunfish, black bass, catfish, suckers, and chain pickerel), crayfish, crabs, shrimp, aquatic insects, tadpoles, water snakes and small terrapins.[24] In Florida, sunfishes and bass, killifishes, and live-bearing fishes are primarily eaten by the anhingas.[25] Other fish eaten include pupfish and percids.[23]
Anhingas stalk fish underwater, mainly where there is some flora present. Once they locate their prey, they partly open their bill and stab the fish swiftly. For larger fish, they use both their jaws and use the lower jaw on small fish.[9] If the fish is too large to forage, the anhinga stabs it repeatedly and then lets it go.[26] The anhingas bring their capture to the surface of the water, toss it backwards and engulf it head-first.[25]
The anhinga is protected in the US under the Migratory Bird Treaty Act of 1918.[27] The number of individual anhingas has not been estimated but they are considered to be of least concern because of the frequency of their occurrence in their 15,000,000 km2 (5,800,000 sq mi) global range.[1]
Male drying its feathers and warming its body, Florida, US
Showing snake-like neck and pointed beak
In flight, South Carolina, US
Juvenile in Uarini, Amazonas, Brazil
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Juveniles with white plumage
Female in Florida, US
Female anhinga in Florida The anhinga (/ænˈhɪŋɡə/; Anhinga anhinga), sometimes called snakebird, darter, American darter, or water turkey, is a water bird of the warmer parts of the Americas. The word anhinga comes from a'ñinga in the Brazilian Tupi language and means "devil bird" or "snake bird". The origin of the name is apparent when swimming: only the neck appears above water so the bird looks like a snake ready to strike. They do not have external nares (nostrils) and breathe solely through their epiglottis.
The anhinga is placed in the darter family, Anhingidae, and is closely related to Indian (Anhinga melanogaster), African (Anhinga rufa), and Australian (Anhinga novaehollandiae) darters. Like other darters, the anhinga hunts by spearing fish and other small prey using its sharp, slender beak.
