Date of Award


Degree Name

Master of Science


Biological Sciences


Jerry D. Johnson


626 Cophosaurus texanus were captured on regular trips to Indio Mountains Research Station in Hudspeth County, Texas from August 2010 to November 2014. Mark-recapture methods using 81 pitfall traps and toe-clips for identification allowed for analyses of long-term trends. 291 adult females, 315 males, and 20 unsexed juveniles were recorded. A total of 180 independent recapture events were documented over the study period (44% females; 55% males). The greatest numbers of C. texanus were collected in 2011 (234), which was also the driest year of the four (6.77 cm), whereas 2014 was the wettest (34.95 cm), but had the second-most number of captures (144). The average temperatures for all the years was not significantly different, although maximum and minimum temperatures varied (2011: 34.95°C, -12.94°C; 2012: 33.15°C, 1.61°C; 2013: 33.08°C, -2.24°C; 2014: 33.85°C, -5.85°C).

Males had an average SVL of 58.27 ± 0.8 mm and an average mass of 7.12 g ± 0.25 g (range: 0.4 â?? 19.5 g), while females averaged 51.45 ± 0.64 mm SVL and had an average mass of 4.8 g ± 0.15 g (range: 0.2 â?? 12.3 g). There was a positive correlation between seasonal temperature and the growth rate for mass. SVL was significantly correlated with monthly precipitation, monthly and daily wind speed, and mean monthly and daily temperatures. Increase in mass was significantly correlated with monthly and daily temperature as well as monthly precipitation. Body condition was significantly correlated with monthly mean temperature, but precipitation amount was not significant for SVL, or body condition. Throughout the study, females had a higher body condition index than males (p = 0.0025), while males had larger growth rates (p = 0.0315). There was no significant difference between combined yearly body conditions or for yearly body conditions by sex.

There were no significant differences between captures or recaptures of males and females over the study period. During the entire study period, 3,550 ectoparasitic mites were counted on all captured and recaptured lizards. By year, the highest number of mites found on both sexes combined was 1,736 in 2011. There was no significant yearly difference among sexes in mite infestation except between 2011 and 2013 (p = 0.0117). The two most infected body locations for both sexes were the cervical and sacral regions.




Received from ProQuest

File Size

101 pages

File Format


Rights Holder

Gabriela Franco