Asymmetries in captured urban rock pigeons Columb livia domestica

Abstract

Asymmetry is a difference in the sizes of bilaterally paired structures. From 41 corpses of urban rock pigeons Columba livia domestica, 10 linear measurements were obtained: body length, tail length, both sides of the length of the second primary (P2), both sides of the length of most external rectrices (R12), both sides of wing length, and both sides of tarsus diameter. Paired structures (length of P2, R12, and wing and diameter of tarsus) were compared in order to obtain values of asymmetries. Left directional asymmetry occurred in P2 and R12. As this asymmetry can have effects on flight parameters, animals with asymmetry were supposed to be less well-fitted animals, but our results suggest that this pattern of asymmetry in this species of low sexual dimorphism may often be better understood in the context of artificial (culling) rather than sexual selection.