Green Sandpiper

The green sandpiper is a small Old World wader and an ancient lineage of its genus, whose only close living relative is the solitary sandpiper. Both nest in trees, unlike most sandpipers. It is a somewhat plump bird with a dark greenish-brown back and wings, a greyish head and breast and white underparts, and dark green legs and bill. In flight its dark wings and brilliant white rump are characteristic (Wikipedia, general species account).

The back is spotted white, most strongly in breeding adults. It has no subspecies (Wikipedia, general species account).