THE SIGNIFICANCE OF CLUTCH-SIZE. Part III.—Some Interspecific Comparisons
Article first published online: 3 APR 2008
Volume 90, Issue 1, pages 25–45, January 1948
How to Cite
Lack, D. (1948), THE SIGNIFICANCE OF CLUTCH-SIZE. Part III.—Some Interspecific Comparisons. Ibis, 90: 25–45. doi: 10.1111/j.1474-919X.1948.tb01399.x
- Issue published online: 3 APR 2008
- Article first published online: 3 APR 2008
- Received on 25 August 1946.
- 1Average clutch-size is characteristic for each genus and each family of birds in the same region.
- 2In almost all families, clutch-size is much smaller in equatorial Africa than in mid-Europe.
- 3In mid-European small passerines, those with comparatively safe nesting-sites tend to have larger average clutches and longer nestling periods than those building open nests.
- 4Swifts and petrels have safe nesting-sites and long nestling periods, but only small clutches, correlated with a scarce or uncertain food supply for the young.
- 5In general, the length of the incubation period is correlated with the length of the nestling period in birds, probably because it is difficult to modify the rate of development except as a whole.
- 6In nidifugous species, the specific differences in clutch-size have not been accounted for, though food for the brood is thought to be the basic factor involved in most cases. The number of eggs that the hen Can cover is not a primary factor in most cases, but may sometimes provide a secondary limit.