Get access

Intra-individual variation in clutch and offspring size in an oviparous snake


Richard A. Seigel, Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252, USA.


Intra-individual variation can be extremely informative in understanding the evolution of life-history traits. In this study, we examined intra-individual variation in clutch and offspring size for brown house snakes Lamprophis fuliginosus, a species that can lay up to six clutches in the laboratory within a 12-month interval without a refractory period. The number of clutches produced per female during this interval ranged from two to six, and there was no significant relationship between the total number of clutches laid and maternal body size. Unlike results from lizards and turtles, house snakes showed no significant changes in clutch size or offspring size among successive clutches, and individual repeatability of both traits was moderate to high. House snakes in this study also showed a strong negative relationship between clutch size and offspring size for all clutches produced, as expected by life-history theory. Our data indicate that house snakes show much less intra-individual variation than most other reptile species examined. However, this high level of consistency may be due to regulation of food availability under laboratory conditions. This will be varied in future experiments to test the degree of plasticity exhibited by individual females for these traits.