Black-necked and Slavonian Grebes by Glyn Sellors

This week's top shot showcases highly unusual behaviour between two similar grebe species. In this cracking image by Glyn Sellors, Black-necked and Slavonian Grebes are shown displaying to each other at St Aidan's RSPB reserve in West Yorkshire, which is a well-known breeding location for the former species. In the case of the 'Slav', this bird has been wintering at the site and has now moulted into breeding condition, where it has now been joined by the arriving Black-necked Grebes, illiciting the remarkable behaviour on show here. Hybrids between the two species have been documented occasionally in the past, so it will be fascinating to see whether the Slavonian hangs around and attempts to breed.

Other notable images

Great Crested Grebe, St Aidan's RSPB (Swillington Ings), West Yorkshire (Gordon Speirs).

Least Sandpiper, Medmerry RSPB, West Sussex (Jeremy Mcclements).

Common Scoter, Hilbre Island, Cheshire (Pierre Montieth).

Slavonian Grebe, St Aidan's RSPB (Swillington Ings), West Yorkshire (Tom Hines).

Eurasian Oystercatcher, Normandy Marsh, Hampshire (Chris Rose).

Black Guillemot, Oban, Argyll (Raoul Chandrasakera).

Eurasian Sparrowhawk, Staines Reservoirs, London (Joe Downing).

Red Kite, Gigrin Farm, Radnorshire (Steve Clare).

Blue Rock Thrush, Formentor, Mallorca, Balearic Islands (Dave Jackson).

Long-tailed Tit, Stoke-by-Nayland, Suffolk (Kit Day).

Common Starling, St Ives, Cornwall (Carl Bovis).

Western Subalpine Warbler, Gibraltar Point NNR, Lincolnshire (Mark Joy).