The black-necked grebe is a striking waterbird known for its agile movements and proficiency in aquatic environments. Its unique adaptations allow it to thrive in diverse wetland habitats across multiple continents. The bird’s life cycle involves seasonal changes and social interactions.
Identification and Appearance
The black-necked grebe exhibits two distinct plumages. During the breeding season, adults display a black head and neck, with golden, fan-shaped plumes extending from behind the eye. A red eye stands out against the dark plumage, complemented by a thin, upturned black bill. The flanks are tawny rufous to maroon-chestnut, while the underparts remain white.
Outside the breeding season, its appearance is more subdued, transitioning to grayish-black on the upper parts, including the crown and a vertical stripe on the back of the neck. The sides of the head and throat are white, with a less defined dark cap. This small grebe, measuring 28 to 34 centimeters, has a compact, streamlined body. Its feet are distinctly lobed, providing efficient propulsion for diving.
Habitat and Distribution
The black-necked grebe has a wide global distribution, inhabiting wetlands across North America, Europe, Asia, and parts of Africa. In North America, it is commonly referred to as the Eared Grebe. During the breeding season, these birds prefer shallow, freshwater lakes, ponds, and marshes that offer abundant aquatic vegetation for nesting and cover.
Following the breeding period, many populations undertake migrations, sometimes traveling as far as 6,000 kilometers. They gather in large flocks at specific staging areas, particularly on saline or hypersaline lakes like the Great Salt Lake or Mono Lake. During this migratory phase, the grebes may become flightless for one to two months while undergoing a complete molt, where they can significantly increase their body weight.
Diet and Foraging Behavior
The black-necked grebe is an underwater hunter, primarily feeding on aquatic invertebrates. Its diet includes aquatic insects and their larval stages, small crustaceans like brine shrimp, and mollusks. It also consumes small fish, tadpoles, and small frogs.
The grebe employs multiple techniques to secure its prey, including diving from the water’s surface to pursue food underwater, propelling itself with its powerful lobed feet. It can also glean insects from foliage, pluck items from the water’s surface, or capture flying insects. When inhabiting highly saline lakes, especially during its molting period, the black-necked grebe adapts its diet to primarily consume brine shrimp found in these environments.
Courtship and Nesting
The courtship rituals of the black-necked grebe are highly synchronized, involving pairs performing dances on the water. One display is the “penguin dance,” where both birds rise upright, breast to breast, paddling rapidly to appear to run across the water’s surface. Another behavior is the “weed rush,” where a pair dives, surfaces with weeds in their bills, and then performs a head-shaking display.
Nests are constructed as floating platforms made from aquatic vegetation, anchored to emergent plants in shallow water. These nests, built by both parents, are cup-shaped and submerged just below the water’s surface. Females lay one clutch, sometimes two, consisting of three to four pale blue eggs, which may become stained brown over time. Both parents share the responsibility of incubating the eggs for approximately 21 days. After hatching, the precocial chicks can swim almost immediately and are carried on the parents’ backs for warmth and protection.