David Lack

After studying at Cambridge, Lack taught zoology at Dartington Hall School. His 1938–1939 Galápagos expedition supplied field observations of the islands’ finches, which he also investigated through comparisons of museum specimens.

This work led to technical publications and the 1947 book Darwin’s Finches. Surviving notes, measurements and drafts document the collection and comparison of material behind the book.

References: [1]

Lack became director of the Edward Grey Institute in 1945. In 1947 he and John Gibb established the Wytham tit study, initially investigating the breeding biology of great tits.

Nest boxes allowed repeated records of breeding attempts, while individual marking connected parents and offspring with later observations. The collaborative study continued beyond Lack’s lifetime and expanded into a long-term population record.

References: [2]

Lack distinguished clutch size, the number of eggs laid, from brood size, the number of young hatched. Hatching failures and experimental manipulations can make these quantities different.

His 1964 communication on swifts and grouse clarified that some brood-size groups in the Oxford swift research had been manipulated. Such groups cannot simply be treated as observations of naturally occurring clutch sizes.

References: [3]

Lack also investigated bird migration using observations that included radar records. His archive preserves migration materials, correspondence and data supplied by other observers.

Together with the breeding records, these sources show a research practice combining field observation, repeated population measurements and instruments, sustained by institute colleagues and amateur contributors.

References: [1]