Whiskered tern

Voice

Hoarse and rasping, and persistent at colonies: a grating krsheck or kerrsh, lower and fuller than Black Tern. When a colony is disturbed the sound swells into a continuous chorus. Heard mainly from May to July over breeding sites; away from the colony the species is usually silent.

Identification

In breeding plumage dark slate-grey underparts between a jet-black cap and a striking white cheek stripe, with white undertail coverts and blood-red bill and legs. The upperwing is pale silvery grey, rump and tail grey. In winter it turns white with a streaked crown, a dark ear patch and a black bill, the body clean white with no breast-side patch. Juveniles show a brown-scaled mantle contrasting with grey wings.

Confusion species

Unmistakable in breeding dress, but winter and juvenile birds closely recall Black and White-winged Terns. Whiskered is larger and heavier, with a longer, thicker bill, broader wings and a uniformly grey rump, and it lacks the dark breast-side patch of Black Tern. At range it can even be taken for a small Common Tern.

Habitat

Shallow, warm fresh and brackish marshes rich in floating-leaved plants: old river arms, fish ponds, rice fields and silting lagoons. Colonies float on beds of water lily, yellow water lily or water soldier. It forages low over water and wet meadows, plucking dragonflies, tadpoles and aquatic insects from the surface.

Range and movements

Centred on southern and eastern Europe, and numerous in Spain, with large colonies in the Ebro delta, the Albufera of Valencia and the marismas of Doñana. It is expanding north and now breeds regularly in the Netherlands, mainly in the peat marshes of Gelderland and Overijssel. Winters in sub-Saharan Africa and around the Mediterranean.

• Resident
• Breeding (summer)
• Winter
• Passage
• Migration direction
• dark = core range, pale = thinly spread

Where and when to look

Visit a peat marsh or rice-field complex in May and June in the early morning, when the air is still and birds hunt low over the vegetation. In the Netherlands search among Black Terns at water-soldier beds; a white-bellied marsh tern with a red bill stands out at once.

Conservation status

Not globally threatened and expanding its European range, helped by rice cultivation and fish farming. Locally it is vulnerable to water management that strands or floods the floating nests, and to the loss of floating-leaved vegetation through eutrophication and carp stocking. In the Netherlands it remains a rare and strictly protected breeder.