Effects of Thermoregulation on Foraging in Anolis carolinensis

Open Access
Trozzo, Lara Rae
Area of Honors:
Biology (Behrend)
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Dr Margaret Voss, Thesis Supervisor
  • Michael A Campbell, Honors Advisor
  • Roger F Knacke, Faculty Reader
  • thermoregulation
  • foraging
  • behavioral thermoregulation
  • anole
  • optimality modeling
  • trade off
  • marine iguana
  • anolis carolinensis
Carolina anoles (Anolis carolensis) use behavioral thermoregulation to maintain internal body temperature within an optimal range to support locomotion. They experience a trade-off when foraging for food because they must travel to an area with lower than optimal temperatures, but they cannot stay too long or their body temperature will drop too low to support bodily functions such as digestion. This trade-off was analyzed by observing the thermoregulatory behavior and monitoring internal body temperature of anoles as they traveled between foraging and basking sites. An optimality model was used to analyze the data and calculate optimal body temperature and the percent time the animals allocate to foraging. At warmer temperatures, anoles spend more time away from the basking site to forage; as the temperature decreases, the duration of foraging trips also decreases. Anoles exhibit hysteresis in that they heat at faster rates than they cool. This results in broad optimal temperature ranges to support active foraging behavior. As a result, anoles can allocate over 90% of their time to foraging in relation to basking and appear to have more flexibility in their activity patterns at lower temperatures than was previously thought.