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Cohort variation, climate effects and population dynamics in a short-lived lizard
Jean François Le Galliard1, Olivier Marquis, Manuel Massot
1CNRS/ENS/UPMC UMR 7625, Laboratoire Ecologie et Evolution, Université Pierre et Marie Curie, 7 Quai St. Bernard, 75005, Paris, France. galliard@biologie.ens.fr
The Journal of Animal Ecology
|July 24, 2010
Summary
Cohort variation significantly impacts short-lived species like the common lizard, influenced by climate. Understanding these cohort effects is crucial for predicting population dynamics and responses to climate change.
Area of Science:
- Ecology
- Evolutionary Biology
- Vertebrate Zoology
Background:
- Demographic theory highlights cohort variation's impact on long-lived species.
- Cohort effects remain understudied in short-lived species.
- The common lizard (Zootoca vivipara) is a suitable model for studying short-lived ectotherms.
Purpose of the Study:
- Quantify cohort effects on demographic traits in the common lizard.
- Investigate the influence of climate conditions on cohort variation.
- Predict population growth consequences stemming from cohort effects.
Main Methods:
- Utilized mark-recapture data from 1989-2005 in two wetland populations.
- Assessed cohort variation and covariation in body size, reproduction, and survival.
- Analyzed immediate and delayed climate effects (temperature, rainfall) on traits.
Main Results:
- Most demographic traits showed significant cohort variation, especially juvenile growth, survival, and breeding phenology.
- Climate conditions (rainfall, temperature) explained some cohort variation, with critical effects during gestation and early juvenile stages.
- Cohort variation primarily impacts population growth through early-life survival rates.
Conclusions:
- Cohort effects are vital for understanding population dynamics in short-lived vertebrates.
- Climate change impacts on critical life stages can drive population fluctuations.
- Predicting species' responses to warming requires knowledge of cohort-specific demographic traits.
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