When heat-acclimated pigeons are exposed to ambient temperatures of 50-60"C, extremely high cutaneous evaporative cooling, together with a high insulative capacity of the feather coat, creates for the bird a microclimate within which physiological processes can be regulated normally. By skillfully using this cooling garment, pigeons maintain their resting metabolic rate and regulate low skin and body temperatures, employing neither panting nor gular fluttering. These physiological achievements parallel those of arctic animals. Hence, during animal evolution towards inhabiting extreme thermal environments, selection seems to have favored adaptations at the lowest energy cost in both the extreme cold arctic and the hottest deserts of the world.
Bibliographical noteFunding Information:
The authors are greatly indebted to Dr. Z. Arad, Dr. A. Borut and Dr. Y.L. Werner for critically reviewing the article. The preparation of this review and the work of J. Marder and associates cited were partly supported by a grant from the Israel Ministry of Agriculture (032-8034).
ASJC Scopus subject areas
- Animal Science and Zoology