The effect of plumage color on the thermoregulatory abilities of Lesser Snow Goose goslings

Abstract

A comparison of the reflectance spectra of Lesser Snow Goose (Chen caerulescens caerulescens) goslings revealed that dark-colored goslings (blues) absorbed more visible and near infrared radiation than did light-colored goslings (snows). Thus, we predicted that blues would obtain greater radiative heat loads and expend less energy to thermoregulate in cold, sunny weather but that radiation would be transmitted deeper into light-colored plumages giving snows a thermal advantage under windy conditions. Using doubly labeled water with penned birds at the La Pérouse Bay colony, we found no significant difference in the daily energy expenditures of blues and snows. Blues tended to expend more energy on windy, sunny days and less on calm, cloudy days but the trends were nonsignificant. We conclude that color has a negligible influence on the energy budgets of Lesser Snow Goose goslings relative to the effect of behavioral thermoregulation.