Plasticity in breeding phenology is not consistent across populations
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Recent studies have identified so-called universal ecological consequences of climate warming, especially an advanced breeding and non-breeding phenology in many populations of plants and animals. In seasonal environments, among species variation in the extent of plasticity of phenology can generate temporal mistmatch between trophic level, where for example predators have higher energetic demands when preys are scarce in the environment. Until recently, however, we knew little about intra-specific variation in breeding phenology, which may vary across populations due to differences in selection or constraints. In a recent study, we combined data from more than 10 years of detailed monitoring of the breeding phenology in 11 populations of common lizards across the Massif Central. Our data demonstrate unambiguously that breeding phenology responds more to climate warming in some populations than in others. Contrary to some predictions from evolutionary theory, plasticity was stronger in warmer and less variable climates.
Picture: The Puy Mary population is characterised by cold and less variable climate conditions during gestation. This population is predicted to exhibit flat plasticity of the breeding phenology. Photograph: J.-F. Le Galliard.
Rutschmann, A., Miles, D. B., Le Galliard, J.-F.,
Richard, M., Moulherat, S., Sinervo, B. and J. Clobert. 2016. Climate and habitat interact to shape the thermal reaction norms of breeding phenology across lizard populations. Journal of Animal Ecology
- Substantial plastic variation in phenology in response to environmental heterogeneity through time in the same population has been uncovered in many species. However, our understanding of differences in reaction norms of phenology among populations from a given species remains limited.
- As the plasticity of phenological traits is often influenced by local thermal conditions, we expect local temperature to generate variation in the reaction norms between population.
- Here, we explored temporal variation in parturition date across 11 populations of the common lizard (Zootoca vivipara) from four mountain chains as a function of air temperatures during mid-gestation. We characterized among-population variation to assess how local weather conditions (mean and variance of ambient temperatures during mid-gestation) and habitat openness (an index of anthropogenic disturbance) influence the thermal reaction norms of the parturition date.
- Our results provide evidence of interactive effects of anthropogenic disturbance and thermal conditions, with earlier parturition dates in warmer years on average especially in closed habitats.
- Variation in the reaction norms for parturition date was correlated with mean local thermal conditions at a broad geographical scale. However, populations exposed to variable thermal conditions had flatter thermal reaction norms.
- Assessing whether environmental heterogeneity drives differentiation among reaction norms is crucial to estimate the capacity of different populations to contend with projected climatic and anthropogenic challenges.
Last Updated ( vendredi, 26 février 2016 )