Black-necked Grebe
The Black-necked Grebe is a member of the grebe family of water birds. It usually measures between 11 and 13 inches in length with a wingspan of 20.5 to 21.5 inches. The common name for this species refers to features visible when the bird is in its breeding plumage.
In breeding plumage, the Black-necked Grebe has a black or blackish-brown coloured head, neck, breast and upper parts with the exception of the golden or ochre-coloured fan or spray of feathers extending behind the eye over the ear coverts and the sides of the nape. The flanks are tawny-rufous to maroon-chestnut and the abdomen is white. The eye is mostly red with a narrow and paler yellow ring on the inner parts of the eye and an orange-yellow to pinkish-red orbital ring. The thin and slightly upturned bill is black and is connected to the eye by a blackish line starting at the gape. The upperwing is blackish to drab brown in colour and has a white patch formed by the secondaries and part of the inner primaries. The underwing is white except the dark tertials and the mostly pale grey-brown outer primaries. The legs are a dark greenish grey. The sexes are similar.
In non-breeding plumage, the Black-necked Grebe has greyish-black upper parts, cap, nape and hindneck. The dark colour of the cap reaches below the eye and can be seen diffused to the ear-coverts. The rest of the neck is grey to brownish-grey in colour and has some white that varies in amount. The breast is white and the abdomen is whitish. The flanks are coloured in a mix of blackish-grey with white flecks. The juvenile Black-necked Grebe is very similar to the non-breeding adult.
The Black-necked Grebe breeds in vegetated areas of freshwater lakes across Europe, Asia, Africa, northern South America and the south west and west USA. After breeding, it migrates to saline lakes and coastal estuaries to moult and over-winter.
In the UK, the Black-necked Grebe can be found all year round although here are only a small number of breeding locations. It is best looked for in winter on reservoirs, gravel pits, estuaries and off the coast.
In the Northern Hemisphere, the Black-necked Grebe breeds from April to August. The male and female build a floating nest of plant matter in the usually shallow water of open lakes and the nest itself is also anchored to the lake by plants. Most of the nest is submerged with the bottom of the shallow cup usually being level with the water. The Black-necked Grebe nests both in colonies and by itself. When it does not nest by itself, it will often nest in mixed-species colonies made up of Black-headed Gulls, ducks and various other waterbirds.
Pair formation in the Black-necked Grebe usually starts during pauses in the migration to the breeding grounds although it occasionally occurs before in wintering pairs. This pair formation continues after arrival on the breeding grounds. Courtship occurs when the bird arrives at the breeding lake and elaborate displays are performed in the middle of the lake. There is no territory involved in courting and birds use the whole area of the lake.
The Black-necked Grebe is socially monogamous but conspecific or intraspecific brood parasitism, where the female lays eggs in the nest of others of their own species, is common with nearly 40% of nests being parasitized on average. However, in terms of territory, breeding pairs will only defend their own nest site.
The female lays a clutch, although sometimes 2 clutches, of 3 to 4 eggs but nests that have been parasitised will have 2 more eggs on average even though the number the host lays is about the same no matter if it has been parasitized or not. The eggs are incubated by both parents for about 21 days. After the chicks hatch, the birds will desert their nest. Even though the young can swim and dive during this time, they rarely do, instead staying on the parents' backs for 4 days after hatching. This behaviour is present in all grebes and is likely to have evolved because it reduces travel, specifically back to the nest to brood the chicks and give them food. After about 10 days, the parents split the chicks up with each parent taking care of about half of the brood. After this split, the chicks are independent in about 10 days and fledge in about 3 weeks.
The Black-necked Grebe forages mainly by diving from the water with dives usually lasting less than 30 seconds. These dives are usually shorter in time when in more shallow water. In between dives, it rests for an average of 15 seconds. The Black-necked Grebe also forages by gleaning foliage, plucking objects off of the surface of water, having its head submerged while swimming and sometimes by capturing flying insects. It eats mostly insects, of both adult and larval stages, as well as crustaceans, molluscs, tadpoles and small frogs and fish.
The Black-necked Grebe is classified as “least concern” by the International Union for Conservation of Nature (IUCN). However, the population trend is uncertain since some populations are decreasing whereas others are stable, have an uncertain trend or are increasing. The justification for the current classification of the Black-necked Grebe is its very large population (estimated around 3.9 to 4.2 million individuals) combined with a large estimated extent of occurrence (about 60 million square miles). It is probably the most numerous grebe in the world.
Date: 18th September 2021
Location: Alexandra Lake, Wanstead Flats, London
In breeding plumage, the Black-necked Grebe has a black or blackish-brown coloured head, neck, breast and upper parts with the exception of the golden or ochre-coloured fan or spray of feathers extending behind the eye over the ear coverts and the sides of the nape. The flanks are tawny-rufous to maroon-chestnut and the abdomen is white. The eye is mostly red with a narrow and paler yellow ring on the inner parts of the eye and an orange-yellow to pinkish-red orbital ring. The thin and slightly upturned bill is black and is connected to the eye by a blackish line starting at the gape. The upperwing is blackish to drab brown in colour and has a white patch formed by the secondaries and part of the inner primaries. The underwing is white except the dark tertials and the mostly pale grey-brown outer primaries. The legs are a dark greenish grey. The sexes are similar.
In non-breeding plumage, the Black-necked Grebe has greyish-black upper parts, cap, nape and hindneck. The dark colour of the cap reaches below the eye and can be seen diffused to the ear-coverts. The rest of the neck is grey to brownish-grey in colour and has some white that varies in amount. The breast is white and the abdomen is whitish. The flanks are coloured in a mix of blackish-grey with white flecks. The juvenile Black-necked Grebe is very similar to the non-breeding adult.
The Black-necked Grebe breeds in vegetated areas of freshwater lakes across Europe, Asia, Africa, northern South America and the south west and west USA. After breeding, it migrates to saline lakes and coastal estuaries to moult and over-winter.
In the UK, the Black-necked Grebe can be found all year round although here are only a small number of breeding locations. It is best looked for in winter on reservoirs, gravel pits, estuaries and off the coast.
In the Northern Hemisphere, the Black-necked Grebe breeds from April to August. The male and female build a floating nest of plant matter in the usually shallow water of open lakes and the nest itself is also anchored to the lake by plants. Most of the nest is submerged with the bottom of the shallow cup usually being level with the water. The Black-necked Grebe nests both in colonies and by itself. When it does not nest by itself, it will often nest in mixed-species colonies made up of Black-headed Gulls, ducks and various other waterbirds.
Pair formation in the Black-necked Grebe usually starts during pauses in the migration to the breeding grounds although it occasionally occurs before in wintering pairs. This pair formation continues after arrival on the breeding grounds. Courtship occurs when the bird arrives at the breeding lake and elaborate displays are performed in the middle of the lake. There is no territory involved in courting and birds use the whole area of the lake.
The Black-necked Grebe is socially monogamous but conspecific or intraspecific brood parasitism, where the female lays eggs in the nest of others of their own species, is common with nearly 40% of nests being parasitized on average. However, in terms of territory, breeding pairs will only defend their own nest site.
The female lays a clutch, although sometimes 2 clutches, of 3 to 4 eggs but nests that have been parasitised will have 2 more eggs on average even though the number the host lays is about the same no matter if it has been parasitized or not. The eggs are incubated by both parents for about 21 days. After the chicks hatch, the birds will desert their nest. Even though the young can swim and dive during this time, they rarely do, instead staying on the parents' backs for 4 days after hatching. This behaviour is present in all grebes and is likely to have evolved because it reduces travel, specifically back to the nest to brood the chicks and give them food. After about 10 days, the parents split the chicks up with each parent taking care of about half of the brood. After this split, the chicks are independent in about 10 days and fledge in about 3 weeks.
The Black-necked Grebe forages mainly by diving from the water with dives usually lasting less than 30 seconds. These dives are usually shorter in time when in more shallow water. In between dives, it rests for an average of 15 seconds. The Black-necked Grebe also forages by gleaning foliage, plucking objects off of the surface of water, having its head submerged while swimming and sometimes by capturing flying insects. It eats mostly insects, of both adult and larval stages, as well as crustaceans, molluscs, tadpoles and small frogs and fish.
The Black-necked Grebe is classified as “least concern” by the International Union for Conservation of Nature (IUCN). However, the population trend is uncertain since some populations are decreasing whereas others are stable, have an uncertain trend or are increasing. The justification for the current classification of the Black-necked Grebe is its very large population (estimated around 3.9 to 4.2 million individuals) combined with a large estimated extent of occurrence (about 60 million square miles). It is probably the most numerous grebe in the world.
Date: 18th September 2021
Location: Alexandra Lake, Wanstead Flats, London
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