Oxygen Consumption, Evaporative Water Loss, and Temperature Regulation of California Gull Chicks (Larus californicus) in a Desert Rookery

Abstract

California gulls (Larus californicus) breeding on barren islets in Mono Lake, California, utilize behavioral responses rather than special physiological adaptations to cope with high environmental temperatures. Young California gulls resemble the chicks of other gull species in oxygen consumption, evaporative water loss rates, thermal conductance, and body temperature. Successful reproduction is dependent on adequate shade for chicks, which are otherwise vulnerable to hyperthermia from high temperatures and intense solar radiation. At present, most shade is provided by parent gulls. Events which decrease nest attentiveness by adults expose the chicks to potentially devastating heat stress.