HOME     SCHEDULE     AUTHOR INDEX     SUBJECT INDEX              

PARENT SESSION

The effects of variation in water availability on Yarrow′s Spiny Lizard (Sceloporus jarrovii) as a member of an ecological community in the Chiricahua Mountains of southeastern Arizona.

Charles, Stevland*,1, Agard, Christopher1, Goode, Matthew3, Middendorf, George1, 1 Howard University, Washington, D.C., U.S.A.3 University of Arizona, Tucson, AZ

ABSTRACT- The southwestern United States has experienced severe and prolonged drought in recent years and only since late 2004 has a significant amount of precipitation been recorded for the region. Our study on the effects of variations in abiotic resources, such as water, on population dynamics focuses on changes in fecundity, survival, and fitness (mass to snout-vent length ratio) in a population of Yarrow′s spiny lizard, Sceloporus jarrovii. The study involved summer surveys of S. jarrovii over a three year period in three similar, adjacent micro-canyons located along Ryolite Canyon in the Chiricahua National Monument in Arizona. Mark-recapture methods were employed and population surveys of S. jarrovii, S. virgatus (twin-striped plateau lizard) and Crotalus lepidus (rock rattlesnake) were conducted for purposes of comparison of the effects on a competitor and a predator species, respectively. Water availability was assumed to be a direct function of recorded precipitation, but was also assessed indirectly by measuring vegetation condition and insect prey density. We anticipate that an increase in precipitation will result in an increase in the average fecundity, survival, and fitness of the population of S. jarrovii. We also examined variation in activity and habitat use by S. jarrovii to determine whether water availability might also affect patterns of activity.

Key words: yarrow's spiny lizard, sceloporus jarrovii, drought, chiricahua

All materials copyright The Ecological Society of America (ESA), and may not be used without written permission.