Title: Whoopers and Bewick's Swans mix it up in Estonia
Post by: Donna on 02-Nov-10, 06:46:04 AM
Comparing whooper swans and Bewick’s swans should be useful for telling them apart: quite often they are seen migrating together. Looking at the plumage and posture it seems as if there were no difference. The Bewick’s swan is smaller than its relative, the neck somewhat shorter, but we must look more in detail at their beaks. The smaller bird seems to have more dark than yellow colour on the beak. The patch at the base of the beak is square with rounded corners.
When they are calling we can distinguish them nicely; difficult to describe but here is an attempt. The whooper swan has a stronger and more ringing voice. Bewick’s swans sound more like geese, the calls are shorter, higher pitched, sometime like dog barks. At the autumn migration there are maybe twenty thousand Bewick’s swans and only a third as many whooper swans. For wintering in open waters 300-900 of the larger swans, but only 30-50 of their smaller relatives stay.