Black-necked Grebe
Podiceps nigricollis
The black-necked grebe usually measures between 28 and 34 centimetres (11 and 13 in) in length and has a wingspan range of 56–60 centimetres (22–24 in) in P. n. nigricollis, and 52–55 centimetres (20–22 in) in P. n. californicus. It weighs 215 to 450 grams (7.6 to 15.9 oz), with males being on average heavier than females. The nominate subspecies in breeding plumage has the head, neck, breast, and upper parts coloured black to blackish brown, with the exception of the ochre-coloured fan of feathers extending behind the eye over the eye-coverts and sides of the nape. Voice: When breeding, the black-necked grebe gives a quiet "ooeek" that ascends in pitch from an already high pitch. This call is also used as a territorial call, in addition to a low and fast trill, which itself is also used during courtship. Another call is a short "puuii" or "wit". This grebe is silent when it is not the breeding season and when it is feeding or resting.
ID text from Wikipedia, CC BY-SA 4.0
Horned Grebe
Podiceps auritus
The species can be recognised by its orange-red and black breeding plumage, its black and white non-breeding plumage, and its characteristic "horns". It is 31–38 cm (12–15 in) long, has a wingspan 55–74 cm (22–29 in) wide and weighs 300–570 g (11–20 oz). It has a moderately long neck, flat forehead and a rear crown of black feathers. Its beak is straight and pointed, with a white tip. The breeding plumage has bright erectable "horns", black fan-shaped cheek feathers and an overall red-and-black colour. Voice: Young begin calling for begging purposes in a slightly trilled peeping noise, similar to that of a domestic chick. As they mature, their song changes to a more adult-like chittering. Their typical advertising call is loud and nasally "aaarrh" descending in a pitch and ending in a trill.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
And 29 more countries.
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Black-necked Grebe and Horned Grebe.