Anhinga, also known as darter, American darter, snakebird, or water turkey, is a water bird native to warmer parts of the Americas. The word “anhinga” comes from the Brazilian Tupi language and means “devil bird” or “snake bird”.
Physical Description
Anhingas are large birds measuring approximately 80–100 cm (31–39 in) in length, with a wingspan of around 120 cm (47 in). Their bodies are long and slim, with long, thin, serpentine necks attached to small heads and long, pointed beaks. Anhingas have short legs that are set far back on their bodies, giving them a profile reminiscent of a water snake when swimming. Males tend to be larger than females.
The plumage of adult anhingas is predominantly blackish-brown, with silvery-white markings on the wings that are noticeable in flight. The feathers have stiff shafts that help repel water from the wings when swimming and diving. Male anhingas develop a pale buff coloration of the head, neck and upper chest during the breeding season. Females acquire a paler gray neck and upper chest.
Distinctive Features
Some of the most distinctive features of the anhinga include:
- Long, slender neck with a small head and pointed beak
- Silvery-white patches on the upper wings visible in flight
- Long tail feathers
- Dense, water-resistant plumage
- Males develop pale head, neck and chest buff coloration during breeding season
- Females develop light gray neck and chest in breeding plumage
- Swims with only its neck above water, resembling a snake
Behavior and Diet
Anhingas are found mainly in freshwater habitats such as swamps, marshes, lakes and rivers. They spend a lot of time swimming and diving underwater in search of food, using their sharp beaks to spear fish. Anhingas have waterproof plumage that allows them to stay submerged for extended periods of time. However, since their feathers are not waterproof, anhingas need to dry out their wings after swimming by perching in the sun with wings outstretched, giving rise to their nickname “snakebird”. This is because of their snake-like swimming posture and winding neck.
The diet of the anhinga consists primarily of fish like perch, sunfish, bass and mullet. They will also eat aquatic invertebrates like shrimp, crayfish and insects. Anhingas hunt by swimming underwater and stabbing their prey with their sharp beaks. They are able to swim and hunt very effectively thanks to their streamlined bodies, flexible necks and pointed bills.
Hunting Technique
Anhingas have a very distinctive hunting technique:
- They swim slowly underwater, propelling themselves with their webbed feet.
- Their long neck allows them to dart their head around in search of prey.
- Once prey is spotted, they swiftly spears it with their sharp, pointed beak.
- They then flip the prey up and swallow it head first.
- Anhingas can stab prey up to one-third their own body length due to their long neck and beak.
- Their streamlined shape and flexible neck allows for quick strikes underwater.
This efficient hunting technique allows anhingas to swim and dive after quick-moving fish and aquatic invertebrates.
Habitat and Range
Anhingas live in freshwater lakes, ponds, marshes, swamps and rivers in warmer regions of the Americas. Their range extends from the southern United States through Central America to central Argentina and Uruguay in South America. They are migratory birds, with northern populations migrating southwards in winter while southern populations migrate based on food availability.
Some key details about anhinga habitats and range include:
- Require freshwater habitats with abundant fish
- Nest in trees or bushes near water
- Breed in southern North America and South America
- Migrate north in spring to breed in summer
- Migrate south in winter to find open water
- Year-round in tropical regions of the Americas
- Migratory populations can cover thousands of miles
Key Habitats
Some prime anhinga habitats include:
- Swamps – Shallow, vegetated wetlands with trees for nesting
- Marshes – Wetlands with reeds, grasses and water plants
- Lakes – Large bodies of fresh water with fish
- Rivers – Slow-moving rivers and streams
- Ponds – Small bodies of fresh water
- Reservoirs – Manmade impoundments
Anhingas require areas with both open water for swimming/diving and trees/shrubs near the water’s edge for perching and nesting.
Range
The anhinga can be found in:
- United States – From Texas to North Carolina
- Mexico – Throughout the country
- Central America – Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama
- Caribbean Islands – Cuba, Jamaica, Hispaniola, Puerto Rico
- South America – Colombia, Venezuela, Guyana, Suriname, French Guiana, Brazil, Ecuador, Peru, Bolivia, Paraguay, Uruguay, Argentina
Breeding and Reproduction
Anhingas breed in colonies near freshwater during spring and summer. They build nests out of sticks in trees or bushes emerging from the water. The male collects nesting material which the female then uses to construct the nest. Nests are bowl-shaped and about 2 feet wide. Anhinga pairs are monogamous and mate for life.
Key facts about anhinga breeding and reproduction:
- Breed in colonies called “rookeries” or “gatorries”
- Nest in trees and bushes overhanging water
- Bowl-shaped nests built from sticks
- Males gather, females build nests
- Lay 2-6 eggs per clutch
- Incubation lasts 25-30 days
- Chicks hatch helpless with eyes closed
- Fledging occurs at 4 weeks
- Cared for by both parents
- Reach sexual maturity at 2-3 years
- Mate for life
Anhinga chicks hatch blind and helpless. They are cared for by both parents who take turns brooding them and bringing fish to feed them. The chicks fledge the nest at around 4 weeks old but continue to be fed by the parents for some time after leaving the nest.
Threats and Conservation
Although still relatively common, anhinga populations face a number of threats across their range:
- Habitat loss and degradation due to human activities
- Disturbance of nesting colonies
- Pollution and water quality deterioration
- Climate change affecting food supply
- Droughts reducing habitat
- Interspecific competition from other piscivorous birds
Conservation actions that would benefit anhingas include:
- Protection and management of wetland habitats
- Monitoring of breeding colonies
- Public education programs
- Sustainable management of reservoirs/ponds
- Reducing use of pesticides and other pollutants
- Restoration of degraded wetlands
- Creation of artificial wetlands/habitat
Due to their reliance on wetland habitats, conservation of the anhinga is connected to broader wetland conservation initiatives across the Americas. Maintaining healthy aquatic ecosystems with good water quality and abundant fish populations is key to preserving anhinga populations into the future.
Relationship to Humans
Anhingas have an ambiguous relationship with humans. On one hand, they are admired for their appearance and fishing skills. Watching anhingas swim and dive can be a popular form of birdwatching. Their snake-like neck and habit of spreading their wings to dry are distinct and intriguing traits.
However, anhingas are also associated with negative impacts:
- Eat commercially valuable fish like bass
- Compete with human fishermen for fish stocks
- Can damage trees they nest and perch in
- Droppings can accumulate below nesting trees
- Perceived as a nuisance around docks/boats
Anhingas are protected across their range, but are sometimes illegally shot or have nests disturbed by anglers or fishermen viewing them as pests. Their tendency to nest colonially makes them vulnerable to disturbance.
In some cultures, anhinga feathers and body parts are used for decorative and spiritual purposes. Overall, active management and education is needed to promote coexistence with these unique water birds.
Fun Facts
Here are some interesting facts about the amazing anhinga:
- Male anhingas develop a pale buff-colored head and neck during breeding season to attract females.
- Baby anhingas hatch blind and naked – completely helpless!
- The anhinga’s scientific name Anhinga anhinga comes from the Brazilian Tupi language meaning “devil bird”.
- Anhingas do not have waterproof feathers like ducks or geese. This allows them to dive and swim easily underwater.
- When swimming, only the anhinga’s head and long neck remain above the water, looking like a snake.
- Anhingas use their stiffened wings and tail to steer and propel themselves when diving underwater.
- By drying their wings in the sun, anhingas allow their waterlogged feathers to become flexible and water resistant again.
- Anhingas are capable of spearing and eating fish up to 1/3 of their own body length!
- The oldest recorded anhinga lived to over 16 years old.
- Legend says the anhinga spear of the Cherokee tribe was made from an anhinga feather or beak.
Conclusion
In summary, anhingas are a fascinating and unique water bird native to the Americas. Their snake-like swimming motion, habit of sunning their wings, and stealthy ability to spear fish make them a distinctive wetland species. Anhingas occupy an important niche in aquatic ecosystems, but face threats from habitat loss and environmental degradation. Maintaining healthy wetlands and educating people about anhingas are key steps to ensuring their future survival. The next time you see an anhinga’s snakelike neck poking above the water, take a moment to appreciate this amazing bird!