Temperature Regulation and the Constraints of Climate in the Eared Grebe

Publication Type:Journal Article
Year of Publication:2003
Authors:Ellis, HI, Jehl, JR
Journal:Waterbirds
Volume:26
Issue:3
Date Published:2003
ISBN Number:1524-4695
Keywords:Podiceps, Podiceps nigricollis, Podicipedidae
Abstract:Abstract Eared Grebes (Podiceps nigricollis) encounter a variety of climatic regimes in their annual cycle. The most dramatic occur while on staging areas in autumn. We investigated the thermoregulatory abilities of the Eared Grebe to determine how they coped with these climate changes during staging. The basal metabolic rate (BMR) was higher than predicted. Mass-specific BMR was 1.212 mL O2/g·h for birds averaging 317 g. The thermoneutral zone is wide and extended from 15°C to 38°C. Minimal thermal conductance and average body temperature were not unusual. We conclude that Eared Grebes live most of the year under thermoneutral conditions and that food availability, not temperature extremes, determines the timing of their winter migration.Abstract Eared Grebes (Podiceps nigricollis) encounter a variety of climatic regimes in their annual cycle. The most dramatic occur while on staging areas in autumn. We investigated the thermoregulatory abilities of the Eared Grebe to determine how they coped with these climate changes during staging. The basal metabolic rate (BMR) was higher than predicted. Mass-specific BMR was 1.212 mL O2/g·h for birds averaging 317 g. The thermoneutral zone is wide and extended from 15°C to 38°C. Minimal thermal conductance and average body temperature were not unusual. We conclude that Eared Grebes live most of the year under thermoneutral conditions and that food availability, not temperature extremes, determines the timing of their winter migration.
URL:http://dx.doi.org/10.1675/1524-4695(2003)026[0275:TRATCO]2.0.CO;2
Short Title:Waterbirds
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