Reproductive Phenology, Fecundity, Survival and Growth of Puerto Rican Anolis Lizards in the Context of Climate Warming
Otero López, Luisa Matilde
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Anolis lizards are vulnerable to climate warming because, like other ectotherms, their basic physiological functions (e.g., locomotion, growth and reproduction) are strongly influenced by environmental temperature. However, before trying to understand the effects of climate warming on these tropical organisms, we need to understand the natural history of the species, what traits can be considered sensitive or vulnerable, and do so at scales that are relevant for the species. This approach allows the construction of baseline databases that can be useful in assessing the effects that current and future climate change will have on the biology and ecology of ectotherms. In this research, we will focus on studying life history traits that we hypothesize to be sensitive to the effects of climate change (particularly climate warming) that have already occurred on Puerto Rican Anolis lizards: reproductive phenology, fecundity, survivorship and growth rates. The first goal of this dissertation is to describe the effects of recent climate warming on the reproductive phenology of Puerto Rican Anolis lizards (Chapter I). Given the temperature increase that has occurred in Puerto Rico due to climate warming, we evaluated if warming has changed the reproductive phenology of Anolis cristatellus and Anolis gundlachi in Puerto Rico in nature. We found that recent climate warming has stimulated reproductive cycles in upland populations while lowland population cycles has been depressed. Since reproductive cycles varied at a regional scale and are very sensitive to environmental temperatures, we decided to evaluate if these cycles would differ between different habitat types (Chapter II). We followed the reproductive cycles of females Anolis cristatellus inhabiting open and forest habitats in two localities (Punta Salinas and Monagas, Puerto Rico) and found a higher proportion of reproductive females in the warmer open environment where lizards can thermoregulate more effectively compared with the forest habitat. In the third chapter we evaluate if other life history traits such as survivorship and growth rates are also sensitive to the observed differences in thermal environment between open and forest habitat. We estimated the survival, body condition and growth rates of Anolis cristatellus for more than a year in two contiguous but thermally distinct habitats (open and forest) in Punta Salinas using capture-mark-recapture methodology. We found that survivorship and body condition are higher in the open habitat, while growth rates are higher in the forest habitat for females (males showed no difference between the two habitats). Results of this dissertation show the importance of considering traits that are vulnerable to climate change (such as reproductive cycles in Puerto Rican Anolis lizards) and most importantly, that local effects can interact with global patterns of climate change to produce complex and unexpected effects in life history traits of tropical ectotherms.