The numbers of this species (and of curlew sandpiper) depend on the population of lemmings. The male curlew sandpiper performs an aerial display during courtship. The elusive corncrake and sanderling, ringed plover and curlew sandpiper are amongst the summer visitors. Migrating species include black-tailed godwit, ruff, little stint, curlew sandpiper and whimbrel. Species seen&colon; Arctic tern, guillemot, razorbill, puffin, whitethroat, little stint, curlew sandpiper and knot.