TITS AND THEIR CATERPILLAR FOOD-SUPPLY

In this paper I review what is known about the relationship between the tits' clutch-size and the timing of their breeding season and the numbers of their caterpillar prey. The results come from the Edward Grey Institute's long-term study of Great and Blue Tits in Wytham Wood, near Oxford. This study was started in 1947 by Drs D. Lack and J.A. Gibb (Lack 1966, Perrins 1979). These results could only have been obtained from a long-term study and emphasize the value of such studies for our understanding of certain aspects of ecology. In addition, they could not have been obtained by a study of the birds alone, being dependent on a knowledge of their insect food; most of this information was made available as a result of a parallel long-term study of the insect fauna of the oak trees, made by a number of people from the Hope Department of Entomology, University of Oxford.