The temporal dimension of life history: case studies of time allocation in individual female reptiles

Time and energy are finite, and their allocation influences organismal fitness and life-history trade-offs. To understand mechanisms regulating life history, we must consider the complex relationship among environment, time and energy allocation, and fitness. Female animals limit population growth rates, making their time allocation important for linking individual processes and behaviors to higher ecological scales. Despite its significance, quantification of time allocation in females is understudied, with most studies focusing on energetics. However, studies directly examining life-history trade-offs in the context of time allocation have provided valuable insight. Using reptiles as model organisms, we present case studies on Timber Rattlesnakes ( Crotalus horridus Linnaeus, 1758) and Canyon Lizards ( Sceloporus merriami Stejneger, 1904) to illustrate the link between environmental factors, female time allocation, and life history. While quantifying time allocation is challenging as a result of delineating behaviors occurring simultaneously, accessing animals, and requiring a significant amount of a researcher's time, recent technological advancements have increased accessibility. Understanding the temporal aspects of life history is essential for developing effective conservation strategies and predicting species responses to climate change. Insights into how females allocate both time and energy have significant implications for ecological theory and conservation initiatives.