-36- 



arid Pecos Shrub Savanna, its flora and fauna are derived from 

 elements of the Texas Hill Country, Tamaulipas Thorn Scrubland, and 

 the Chihuahua Desert (Texas Parks and Wildlife, 1982b). It is 

 considered a true desert habitat, receiving 25 cm or less 

 precipitation annually. The nearest weather station, Amistad Dam, 

 recorded average maximun and minimum temperatures for June 1982 of 

 36°C and 23°C, respectively, with daily temperatures frequently rising 

 above 38°C during the summer months (US Department of Commerce, 

 1982a). Relative humidity was not measured, but probably averaged 

 below 30% during the summer. Mammalian inhabitants at the park are 

 limited to coyote, jack rabbit, armadillo, and small rodents. 



Site D . Fawcett Boy Scout Camp, Barksdale, Edwards County, Texas 

 (11 and 22 June, 1982; Fig. 2-8). This site is located 7 km north of 

 Barksdale at a bend in the Nueces river. Also at the southern edge of 

 the Edwards plateau, the habitat resembles Garner State Park in most 

 features, but lacks steep, rocky hills. The nearest weather station 

 is about 20 km south at Camp Wood (US Department of Commerce, 1965). 

 Annual precipitation for the ten-year period of 1951-1960 averaged 

 59.8 cm with a range of 22.3 cm to 106.1 cm. Average daily maximum 

 and minimum temperatures during June 1982 were 33°C and 21°C, 

 respectively (US Department of Commerce, 1982a). 



Site E . Myer's Farm, D'Hanis, Medina County, Texas (19-30 

 September, 1983). This farm, the home of patient D, is in a small 

 rural community 75 km west of San Antonio. The surrounding area is 

 characterized by low rolling farmland with live oak, pecan, and 

 mesquite trees bordering the fields and streams (Fig. 2-9). 

 Uncultivated areas are overgrown with cactus, mesquite and thorny 

 shrubs. One such area, about 50 m west of the farm house, contains a 



