Meeting Abstract
Interspecific comparisons have yielded insight into regarding relationships between field locomotor behavior and performance capacities. Among species of lizards, endurance capacity measured on a motorized treadmill is positively related to daily movement distance and time spent moving, but few studies have addressed such relationships at the level of individual variation within a sex and age category in a single population. Both endurance capacity and home range size show substantial individual variation in lizards, rendering them suitable for such studies. This variation may be positively related, as endurance capacity might act as one of the factors limiting home range size. In this preliminary study, we measured the endurance capacity and home range size of 16 adult male desert iguanas (Dipsosaurus dorsalis) near Palm Springs, CA during May-June 2015. Lizards were field-captured for measurements of endurance; home range data was gathered using visual identification of individuals. Endurance was repeatable between replicate trials, conducted 1-17 days apart (r = 0.718 for log-transformed values, N = 16, 2-tailed P = 0.002). The higher of two endurance values averaged 21.8 ± 14.6 min (SD; range = 3.2 – 51.5 min), while mean home range size was 109.8 m2 ± 111.9 (SD; range = 15.7 – 482 m2). Log home range size (adjusted for # of captures) was not significantly related to log endurance, whether or not body mass was used to compute residual values. This result suggests the possible importance of additional factors impacting home range size, such as intraspecific interactions or variation in microhabitat characteristics. Further work will examine endurance-home range relationships in other seasons and incorporate data on relevant ecological factors and social interactions.
