Watch your waders
BY now several wader species will be transforming from their dull winter plumages to bright spring colours. No longer is Dunlin dull mouse-brown above and silvery-white below, or Sanderling pale grey and sparkling white with a darker forewing.
Dunlins become variably streaked with brown, chestnut, yellow-ochre and black above and gain a unique square-fronted black belly patch. Scandinavian alpina is larger, longer billed, more rusty-red above than British- (and Iceland- and northern European-) breeding schinzii, but such average differences are best noticed in a large sample than individually.
Sanderlings become more colourful and varied, with a marbled breastband – but always white belly – and speckles of black and chestnut above. These new head and body feathers, grown from January, are broadly edged with white, but the white quickly wears off, so the hoary, frosted look on the back, head and breast becomes richer, more solidly ginger/tawny and black by May.
Similar changes turn grey, anonymous Red Knots to bright
tawny-red beneath. Godwits also gain this difficult-to-describe rich orange-red colour beneath. Male Bar-tailed Godwits achieve a full red from chin to tail, whereas females are duller, mixed buff, white and rufous, with most clear red on the upper breast and narrow dark bars on the flank. Black-tailed have a more distinct separation of coppery-red on the head, neck and breast, whiter on the belly and flank, with longer, broader, blacker flank bars. The winter-visiting Icelandic breeding subspecies islandica is deeper, more uniformly red than the longbilled British/continental limosa.
Even the quiet, inconspicuous Purple Sandpiper gains some white-edged rufous feathers on the head and back, the white wearing off and the dull yellow legs getting darker as breeding colours are fully developed. Rob Hume