SREL Reprint #2083

Relationships between genetic variation and body size in wintering mallards

Olin E. Rhodes, Jr.1, Loren M. Smith2, and Michael H. Smith1

1Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29801, USA
2Department of Range and Wildlife Management, Texas Tech University, Lubbock, Texas 79409, USA

Abstract: Mallards (Anas platyrhynchos; n = 282) wintering in the Southern High Plains (SHP) of Texas were collected from 15 October 1988 to 7 February 1989. Lipid and fat-free body masses were determined for all Mallards. Birds were surveyed electrophoretically for genetic variation at 30 biochemical loci. Our objective was to determine if structural size, fat mass, or fat-free mass of Mallards were related to multilocus genetic variation. Wing-chord length, our estimator of structural size in Mallards, was shortest in female Mallards with the highest levels of genetic variation. Fat mass and fat-free mass of Mallards (corrected for size) were not related to multilocus heterozygosity. Mixtures of morphologically and genetically differentiated breeding populations of Mallards on the SHP wintering area may explain the relationships between multilocus heterozygosity and size we detected in these birds.

SREL Reprint #2083

Rhodes, O.E., Jr., L.M. Smith, and M.H. Smith. 1996. Relationships between genetic variation and body size in wintering mallards. The Auk 113:339-345.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).