Pennycuick, Colin James (1933– )

English zoologist who has studied the various processes involved in flight. He discovered that many migratory birds have minimal energy reserves and must stop to feed at regular intervals. The destruction of the intermediate feeding places of these birds could lead to their extinction, even if their summer and winter quarters are conserved.

Pennycuick was born in Virginia Water, Surrey, and studied at Oxford and Cambridge. In 1964 he became a lecturer at Bristol University, with a break 1971–73 spent researching at Nairobi University in Kenya.

Pennycuick's research is unusual in that it interrelates an extremely large number of factors and therefore gives a very detailed account of flight. In flying vertebrates, for example, he has investigated the mechanics of flapping; the aerodynamic effects of the feet and tail; the physiology of gaseous exchange; heat disposal; the relationship between the size and anatomy of a flying creature and the power it develops; and the frequency of wing beats.

Pennycuick has also hypothesized that migratory birds navigate using the Sun's altitude and its changing position.