The horned grebe (Podiceps auritus) is a comparatively small waterbird that is distributed throughout North America and Eurasia, there being two respective subspecies. In length it reaches 31 to 38 centimetres, its wingspan is 55 to 74 centimetres and it weighs approximately 300 to 570 gram.
In comparison to the breeding-plumage, the non-breeding plumage is rather dull and boring, being greyish-black and white. The cheeks, chest and belly are coloured in a pale white tone, whereas the back and crown are black.
The breeding plumage of the horned grebe has bright erectable horns (which is how the species has gotten its name), black fan-shaped cheek feathers and an overall red and black colour. The neck, flanks lores and upper chest are chestnut brown, while the crown and back are black. Males and females look very similar, but males are a bit larger and brighter.
The habitat changes with season, but horned grebes always live in either lakes, ponds, or the ocean. During the summer they greatly prefer lakes with some open water and a bit of marsh vegetation, whereas in the winter they mostly occur in oceans, and more recently some large lakes and reservoirs as well.Â
Much like their habitat, the diet of horned grebes also changes seasonally, but generally consists of aquatic insects, fish and crustaceans. In the summer insects, crustaceans, salamanders, leeches and small amounts of plant material make up the majority of their diet, but in the winter it is dominated by fish, with molluscs and some insects making up only a small part of their prey.
Like other species of grebe, the horned grebe also regularly swallows its own feathers, so much that its stomach usually contains a matted plug of them. Parents also feed their feathers to their chicks so that they get this plug early. This may function as a filter for fish bones, to hold them in the stomach until they can be fully digested.Â
The female lays 3 to 7 whitish or pale green eggs, which are incubated by both males and females. Almost immediately after hatching (which takes about 25 days) the young are capable of swimming, but usually ride on their parents back, even diving with them sometimes. Although the horned grebe usually has one only one brood in a year, that number can change and be up to two. If there are two broods itâs common for the chicks of the first brood to help raise and feed the second.
Due to a lack of solid data, it is difficult to say whether or not horned grebes are declining or not, but that is believed to be the case. Current population estimates suggest that there are about breeding 620000 individuals currently alive, about 250000 of which are in North America. The IUCN rates this species as Vulnerable.
Photo credits: Ed Rosack, Ăskar Sigurmundason, Sindri SkĂşlason