These authors contributed equally to this work.
Length of activity season drives geographic variation in body size of a widely distributed lizard
Article first published online: 21 JUN 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Ecology and Evolution
Volume 3, Issue 8, pages 2424–2442, August 2013
How to Cite
Ecology and Evolution 2013; 3(8): 2424–2442
- Issue published online: 12 AUG 2013
- Article first published online: 21 JUN 2013
- Manuscript Accepted: 24 APR 2013
- Manuscript Revised: 17 APR 2013
- Manuscript Received: 4 FEB 2013
- Slovak Republic VEGA. Grant Number: 1/0491/10
- Spanish Ministry of Education and Science. Grant Numbers: CGL2005-01187, CGL2008-01522
- Swiss National Science Foundation. Grant Number: PPOOP3_128375
- Academy of Finland. Grant Number: 108955
- European Science Foundation. Grant Number: EG/3312
- Grant Agency of the Slovak Republic VEGA. Grant Numbers: CGL2005-01187, CGL2008-01522, PPOOP3_128375, 108955, EG/3312
- Bergmann's rule;
- ecogeographic variation;
- life-history traits;
Understanding the factors that drive geographic variation in life history is an important challenge in evolutionary ecology. Here, we analyze what predicts geographic variation in life-history traits of the common lizard, Zootoca vivipara, which has the globally largest distribution range of all terrestrial reptile species. Variation in body size was predicted by differences in the length of activity season, while we found no effects of environmental temperature per se. Females experiencing relatively short activity season mature at a larger size and remain larger on average than females in populations with relatively long activity seasons. Interpopulation variation in fecundity was largely explained by mean body size of females and reproductive mode, with viviparous populations having larger clutch size than oviparous populations. Finally, body size-fecundity relationship differs between viviparous and oviparous populations, with relatively lower reproductive investment for a given body size in oviparous populations. While the phylogenetic signal was weak overall, the patterns of variation showed spatial effects, perhaps reflecting genetic divergence or geographic variation in additional biotic and abiotic factors. Our findings emphasize that time constraints imposed by the environment rather than ambient temperature play a major role in shaping life histories in the common lizard. This might be attributed to the fact that lizards can attain their preferred body temperature via behavioral thermoregulation across different thermal environments. Length of activity season, defining the maximum time available for lizards to maintain optimal performance, is thus the main environmental factor constraining growth rate and annual rates of mortality. Our results suggest that this factor may partly explain variation in the extent to which different taxa follow ecogeographic rules.