by Willem van der Merwe
Our featured bird of the day is a Black-necked Grebe Podiceps nigricollis. In America, it is sometimes called the Eared Grebe. It is related to the Great Crested Grebe, which was featured here before, but is rather smaller, reaching only 33 cm in length. My picture shows it in breeding plumage, with a deep black head and neck, contrast- ing with the long, golden-orange cheek plumes. Both males and females have this breeding plumage. The rest of the body is black as well, except for the side feathers, which are deep rufous-brown, and a whitish belly. Out- side the breeding season, this grebe has a greyish to blackish colouration on the back and sides and white on the throat, neck and belly. It also then lacks the long cheek plumes. It has a characteristic habit that makes identification easy: it often rolls to one side to preen its flank feathers, exposing its white belly.
This is a species I haven’t seen yet, even though it occurs very widely. They’re rather patchily distributed over Africa but occur as resident or breeding birds over much of Europe, Central and Eastern Asia, and North America. It does occur over much of South Africa but is rare in the Limpopo Province, being more prevalent to the west and south. Its favourite breeding habitats are large, seasonal expanses of shallow water, often of high salinity, such as in the ‘salt pans’ found over much of the interior. These occur in rather arid regions and are often dry, only filling up in years of high rainfall. Consequently, Black-necked Grebes are nomadic, flying around to find the best spots each season. They can cover distances of as much as 6000km on migration. Despite this, they’re not very good at flying, having rather short and narrow wings. They moult their flight feathers immediately after completing the migration, and until their new feathers are grown, they’re flightless. But they feed enough for them to regain the strength and body weight lost during the migration. Sometimes they can double their weight! Outside of the breeding season, they live on various kinds of open water and sheltered bays along the coast.
Having shorter bills than Great Crested Grebes, Black-necked Grebes feed on smaller organisms. They typically dive for less than 30 seconds at a time. They catch aquatic invertebrates both beneath and on the water’s surface. They also pick them off the leaves of aquatic vegetation. They’re fast enough to snap insects out of the air. While moulting on large salt pans, they feed on the abundant brine shrimp that thrive in such conditions. They take small fishes, frogs and tadpoles too.
In South Africa, these grebes breed on large expanses of water with emergent vegetation and often some flooded trees. Like in the Great Crested Grebe, the male and female perform elaborate displays to each other to strengthen their bond. They utter courtship and territorial calls: a squeaky whistle and a trill. They build their nests singly or in colonies. The nest is a big heap of floating vegetation anchored to the bottom or to aquatic plants. The female lays two to four eggs but sometimes lays an egg or two in the nest of a different couple, so that nests may occasionally have up to six eggs in them. Both sexes incubate. As in the Great Crest- ed Grebe, they may cover the eggs with vegetation if they leave the nests due to a disturbance. The chicks hatch with a downy covering and open eyes. Although they can swim already, for a few days, they mostly ride around on their parents’ backs. The parents catch food and hand it to the chick’s beak-to-beak. They may also drop food items on the water surface for the chicks to pick up. This way, the chicks gradually learn to catch their own food.
The Black-necked Grebe may be the most abundant grebe in the world at present, with a population that might number over 4 million individuals. It occurs very widely and is not considered endangered. It did suffer in the past, as the Great Crested Grebe did, from being hunted for its soft plumage or ‘grebe fur’. It is still hunted on a small scale in some places. It also is vulnerable to various outbreaks of diseases carried by the small invertebrates and fish on which they feed, such as the West Nile virus. But because these grebes can raise two clutches of eggs in good breeding seasons, they can rapidly recover their numbers after disease epidemics. They’re occasionally harmed by oil spills along the coast.
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