-35- 



The nearest weather station to Garner State Park is 50 km south at 

 Uvalde where the climate is fairly representative of the area 

 surrounding the park, characterized by hot, humid summers and 

 pleasantly mild winters (US Department of Commerce, 1965). Annual 

 precipitation averaged 63.1 cm between 1951 and 1960, with a range of 

 23.3 cm to 98.3 cm. The wettest periods of the year are May-June and 

 September-October. The hottest part of the year is July-August, with 

 extreme temperatures reaching a high of 43°C, and a low around -15°C, 

 reached in January and February. Relative humidity at noon, central 

 standard time, averages between 58% in January to 48% in July. Daily 

 fluctuations in RH occur especially during the warmer months, with a 

 gradual decrease in the afternoon until sunset, then a rapid increase 

 after dark (US Department of Commerce, 1965). Average daily maximum 

 and minimum temperatures for June 1982 were 35°C and 22°C, 

 respectively, and precipitation 14.4 cm (US Department of Commerce, 

 1982a). Average daily maximum and minimum temperatures for September 

 1983 were 34°C and 21°C, respectively, with 7.9 cm precipitation (US 

 Department of Commerce, 1983a). 



Site B . Rio Frio, Real County, Texas (4-20 June, 1982). This 

 site is located approximately 20 km north of Site A, at the edge of a 

 small gorge carved by the Frio river. The habitat and climate are 

 very similar to that found at Garner State Park. 



Site C . Seminole Canyon State Park, Val Verde County, Texas (10- 

 11 June, 1982; Fig. 2-7). This state historical park is located 75 km 

 west of Del Rio, Texas, a short distance downstream from the 

 confluence of the Rio Grande and Pecos Rivers. It is noted for its 

 rugged terrain, sparse vegetation and deep canyons. Situated in the 



