The black-necked stilt is a very elegant wading bird with long pink legs and a distinctive black and white plumage. It is found in coastal habitats across North America, parts of South America, and Hawaii. In Hawaiian, the black-necked stilt is known by the name aeo. This name refers to the stilt’s long, thin legs and its habit of wading in shallow water in search of food.
Introduction to the Black-Necked Stilt
The black-necked stilt (Himantopus mexicanus) is a member of the avocet and stilt family Recurvirostridae. It is a fairly large wading bird with a slender body, long pink legs, and a long slim black bill. Adult black-necked stilts have striking black and white plumage. The head, back, wings and tail are black, while the underside of the body is white.
Distinctive features of the black-necked stilt include its exceptionally long pink legs and its long thin neck. The legs make up around two-thirds of the bird’s total height. This allows it to wade through shallow water to find food while keeping its body dry. The long neck enables the black-necked stilt to reach down and snap up prey.
Black-necked stilts are found along the Pacific and Gulf Coasts of North America, in Central and South America, and in Hawaii. Their habitat includes coastal salt marshes, ponds, tidal mudflats and shallow lakes. They nest on the ground, often on small islands in salt marshes or lakes. Nests consist of scrapes or depressions lined with vegetation and shells.
Physical Description
Let’s take a closer look at the physical features and appearance of the black-necked stilt:
- Size: These birds measure 13-16 inches in length and have a wingspan of about 32 inches.
- Legs: The legs are slim, long and bright pink in color. They make up around two-thirds of the bird’s total height.
- Bill: The bill is long, straight and very thin. It is black and measures around 2-3 inches in length.
- Plumage: Adults have striking black and white plumage. The head, neck, back, wings and tail are black, while the underside of the body is white.
- Eyes: Their eyes are brown with a red orbital ring around each eye.
Female black-necked stilts tend to be slightly larger than males, but otherwise the sexes look alike. Immature birds have a browner plumage with a white belly and gray legs.
Diet and Feeding
The black-necked stilt is carnivorous and feeds primarily on aquatic invertebrates. Its slender bill allows it to deftly pluck small prey items from mud or water. Typical prey includes:
- Insects: Water beetles, flies, grasshoppers, dragonflies
- Crustaceans: Shrimp, aquatic snails, crabs
- Worms
- Small fish
- Tadpoles and frogs
Stilts employ a wide range of foraging techniques to catch prey. They may pick insects directly off plants, snatch worms from mud, quickly stab fish or tadpoles, or shuffle their feet to stir up food from the bottom of shallow water. They also sometimes submerge their heads underwater to reach food sources.
Behavior and Habits
Here are some interesting facts about the behavior and habits of black-necked stilts:
- Foraging: They forage both day and night, walking slowly through shallow water or muddy shorelines probing for prey. Their long legs allow them to wade through water while keeping their bodies dry.
- Nesting: Nests are simple scrapes or depressions in the ground lined with shells and vegetation. Nesting usually occurs from April to August.
- Migration: Northern populations migrate south for the winter, while some southern groups are permanent residents. Migrating flocks fly in elongated lines or V-formations.
- Social: They are gregarious birds and nest in loose colonies. Both parents share incubation duties.
- Vocalizations: Common calls include high-pitched squealing or whistling sounds. They use calls to communicate alarm or to defend territory.
- Lifespan: In the wild, black-necked stilts may live up to 10 years. Their main predators are birds of prey, gulls and crows.
Range and Habitat
The black-necked stilt has a very wide range across North, Central and South America. Their breeding habitat extends from the Pacific Coast of North America to Chile and Argentina. Some key areas include:
- West Coast of North America from British Columbia to northwest Mexico
- Gulf Coast from Florida to eastern Mexico
- Caribbean islands
- Scattered inland locations in the western and southwestern United States
- Central valley of California
- Coastal regions of Central and South America
- Hawaiian Islands
Black-necked stilts are found in a variety of shallow wetland environments. Typical habitat includes:
- Coastal salt marshes and estuaries
- Intertidal mudflats
- Ponds, lakes and lagoons
- Flooded agricultural fields
- Irrigation canals and ditches
- Sewage treatment ponds
- Evaporation ponds
Status and Threats
The global population of black-necked stilts is estimated to be over 500,000 individuals. Although they remain widespread and common over much of their range, they face threats in some areas due to habitat loss from human activities. Some key threats include:
- Coastal development reducing wetland nesting habitat
- Pollution and water quality degradation
- Disturbance of nesting colonies
- Overgrazing and agricultural conversion of wetlands
However, black-necked stilt populations are considered stable overall. They are listed as a species of Least Concern by the IUCN Red List. Protecting coastal wetlands and inland water bodies will be important for the continued survival of breeding and wintering populations.
The Hawaiian Name ‘Aeo’
The Hawaiian name for the black-necked stilt is ‘aeo. In the Hawaiian language, the name refers to the stilt’s slender legs and its behavior of wading through shallow waters searching for small prey.
Two subspecies of black-necked stilts occur in Hawaii:
- Himantopus mexicanus knudseni – nominate subspecies found on most islands
- Himantopus mexicanus pacificus – subspecies restricted to Laysan Island
Hawaiian stilts can be found foraging in a variety of shallow wetland habitats including:
- Fishponds
- Taro fields
- Mangrove swamps
- Mudflats
- Salt marshes
- Flooded pastures
The Hawaiian name ‘aeo beautifully captures the appearance and graceful walking style of this elegant wading bird. When visiting Hawaii’s wetlands, listen for the distinctive high-pitched calls of ‘aeo and watch for their bold black and white plumage as they forage in shallow waters.
Conclusion
The black-necked stilt is a striking and graceful wading bird that thrives in coastal and inland wetland habitats. With its jet-black plumage, bubblegum pink legs and slender neck, it is a beautiful sight whether wading through shallow waters feeding or flying in neat formations during migration.
Across its range from North America to South America, this species is known by many common names. But in Hawaii it carries the melodic name of ‘aeo, capturing its slender legs and delicate walking style as it hunts for food. Protecting fragile wetland ecosystems will be crucial for the continued survival of Hawaiian and global populations of this elegant long-legged bird.
