Common Greenshank
Tringa nebularia
Common greenshanks are brown in breeding plumage, and grey-brown in winter. When in water, they can appear very similar to marsh sandpipers but are distinguished by the shape of the lower bill which gives it an upturned appearance to the bill. They have long greenish legs and a long bill with a grey base. They show a white wedge on the back in flight. They are somewhat larger than the related common redshank. The usual call is a rapid series of three short fluty notes syllabilized as teu-teu-teu. Like most waders, they feed on small invertebrates, but will also take small fish and amphibians.
ID text from Wikipedia, CC BY-SA 4.0
Green Sandpiper
Tringa ochropus
This species is a somewhat plump wader with a dark greenish-brown back and wings, greyish head and breast and otherwise white underparts. The back is spotted white to varying extents, being maximal in the breeding adult, and less in winter and young birds. The legs and short bill are both dark green. It is conspicuous and characteristically patterned in flight, with the wings dark above and below and a brilliant white rump. The latter feature reliably distinguishes it from the slightly smaller but otherwise very similar solitary sandpiper (T. solitaria) of North America.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
And 116 more countries.
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Common Greenshank and Green Sandpiper.