Meeting Abstract
Many ecological studies support the idea that the importance of biotic limits (e.g., predation) decreases with increasing latitude, just as the importance of abiotic limits (e.g., climate) increases with latitude. Thus, as latitude increases, the life-history strategy of species should shift from being limited by biotic to abiotic factors. We tested for shifts in life-history strategy across a latitudinal gradient in a widespread lizard, common side-blotched lizards. We hypothesized that growth rate and energy storage will increase with latitude due to shorter growing seasons and to withstand longer, harsher winters, respectively. We reared side-blotched lizards from 12 populations from Nevada (mid-) and Oregon (high-latitude) under common lab conditions to measure their growth rates and quantify their energy storage prior to winter. Contrary to our expectations, lizards from low latitudes had higher growth rates and greater energy storage than those from higher latitudes suggesting that high-latitude populations are not limited by either the local predation environment or winter harshness. However, results suggest that populations from mid latitudes (i.e. central Nevada) are limited by both predation and winter mildness requiring both rapid growth and high energy storage.
