Joel Asaph Allen

Joel Asaph Allen
Born	(1838-07-19)July 19, 1838 Springfield, Massachusetts
Died	August 29, 1921(1921-08-29) (aged 83)
Nationality	American
Alma mater	Harvard University
Known for	Allen's rule
Parents	Joel Allen (father) Harriet Trumbull (mother)
Scientific career
Fields	Ornithology Zoology
Institutions	American Academy of Arts and Sciences Museum of Comparative Zoology American Association for the Advancement of Science Audubon Society American Philosophical Society
Author abbrev. (zoology)	Allen, J.A. Allen

Joel Asaph Allen (July 19, 1838 – August 29, 1921) was an American zoologist, mammalogist, and ornithologist. He became the first president of the American Ornithologists' Union, the first curator of birds and mammals at the American Museum of Natural History, and the first head of that museum's Department of Ornithology. He is remembered for Allen's rule, which states that the bodies of endotherms (warm-blooded animals) vary in shape with climate, having increased surface area in hot climates to lose heat, and minimized surface area in cold climates, to conserve heat.