These are both small
migratory waders, greyish brown on top and white underneath, with a distinctive stiff-winged flight low over the water. The
plumages are very similar, apart from spotted sandpipers' distinctive breeding plumage, and suspected out-of-range
vagrants must be carefully observed for identification to species. Both species have short yellow or yellowish legs and a medium
bill. These are not gregarious birds and are seldom seen in large flocks. They nest on the ground, and their
habitat is near
fresh water. These birds
forage on the ground or in water, picking up food by sight. They may also catch
insects in flight. They eat insects,
crustaceans and other
invertebrates.
Actitis is part of the
shank-
tattler-
phalarope clade and less closely related to the
calidrid sandpipers. Based on the degree of
DNA sequence divergence and putative shank and phalarope fossils from around the
Oligocene/
Miocene boundary some 23–22
million years ago, presumably
Actitis diverged from its closest relatives in the
Late Oligocene; given the much higher diversity of the prehistoric members of the group in
Eurasia it is likely that they originated there, possibly being isolated as the remains of the
Turgai Sea dried up, which happened just around this time. The
Late Pliocene fossil described as
Actitis balcanica appears to be actually from some indeterminate
charadriid. ==Footnotes==