This lovely, colourful, small grebe (not much bigger than a Little Grebe) breeds in tiny numbers (fewer than 40 pairs) in Scotland. The bulk of its breeding range, however, is across middle northern Eurasia, from Iceland and Scandinavia to far-eastern Russia as well as Alaska and Canada. But it doesn’t breed in Slavonia, which is a region of Croatia. It does winter off the Croatian coast (as well as many other coasts, of course). It really isn’t a peculiarly Slavonian bird, so the name is something of a mystery.
In North America it is called the Horned Grebe, which is perhaps a better name, but also a bit lame as many grebes have something resembling ‘horns’ in their plumage. Much more fun are old folk names which include Devil-diver, Pink-eyed Diver, and Water Witch.
But to British birders it will always be the Slav.