Can someone with experience with both races of Rock Sandpiper and with Purple
Sandpiper tell me if the difference in bill length between both Purple
Sandpiper and Pribilof Rock Sandpiper and Aleutian Rock Sandpiper is as great
as Sibley's illustrations suggest. Is there overlap in culmen length between
the Aleutian Rock and the other two? And is the difference in bill length a
useful characteristic in field identification?
Darrel
