Elevational Variation of Body Size in Crested Ducks (Lophonetta specularioides) from the Central High Andes, Mendoza and Patagonia

BULGARELLA, MARIANA; WILSON, ROBERT E.; KOPUCHIAN, CECILIA; VALQUI, THOMAS H.; MCCRACKEN, KEVIN G.

ORNITOLOGIA NEOTROPICAL

NEOTROPICAL ORNITHOLOGICAL SOC

Año: 2007 vol. 18 p. 587 - 602

1075-4377

The Crested Duck (Lophonetta specularioides) inhabits the Andes of South America from Tierra del Fuego to central Perú, with two subspecies (L. s. specularioides and L. s. alticola) inhabiting different elevational environments in the Andes from sea level to 5,000 m. We evaluated morphological differences between the two subspecies of Crested Duck and evidence for Bergmann’s and Allen’s Rules to gain a better understanding of the forces that have acted to shape geographic variation in morphology of highland and lowland populations. Overall body size of Crested Ducks differed between subspecies and between sexes. Male and female L. s. alticola from the central high Andes sampled at 3,338–4,611 m were larger than L. s. specularioides from southern Patagonia (