Comparisons of Whooper Swans on Scillies in 2009 and 2012

All photographs copyright Paul Gale Bird Photography

Whooper swans live for many years, pair for life and migrate each and every year, typically to the same wintering grounds (e.g. Caerlaverock WWT in South west Scotland and Welney WWT on the Ouse Washes). Individual adult Whooper swans can be distinguished by the patterns on their bills. One use of digital photography is to compare individuals. Here the bill patterns of the six adult birds on St Agnes in 2009 are compared with those of the eight adult birds on St Mary's in 2012. Twelve birds are clearly different individuals, while two show some similarity in terms of asymmetry of the pattern. These two  birds are directly compared below. The bill patterns are sufficiently different to conclude that all fourteen birds are different individuals. This is consistent with my hypothesis that Whooper swans seen in October on the Scillies represent small flocks of birds off course from their regular wintering ground rather than birds on a regular migration route.

Whooper Swan 3 2009	Whooper Swan 5 2012

2009

2012

Whooper Swan 1 2012	Whooper Swan 2 2012	Whooper Swan 3 2012
Whooper Swan 4	Whooper Swan 5 2012	Whooper Swan 6 2012
Whooper Swan 7 2012	Whooper Swan 8 2012	Whooper Swan 9 2012

Scillies All Years

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