SREL Reprint #2089

STATUS OF THE BUNCH GRASS LIZARD, SCELOPORUS SCALARIS, IN THE CHIRICAHUA MOUNTAINS OF SOUTHEASTERN ARIZONA

Royce E. Ballinger and Justin D. Congdon

The bunch grass lizard (Sceloporus scalaris) inhabits high elevation sites in the Sierra Madre Occidental of Mexico (Smith, 1939; Thomas and Dixon, 1976). Its range extends into the mountain islands and high grasslands of southwestern New Mexico and southeastern Arizona where it is common especially on east and south facing slopes having a vegetative cover of dense grasses. Recent ecological work (Newlin, 1976; Ballinger and Congdon, 1980 and 1981; Smith, et al. 1993) revealed a pattern of winter activity and a life history typical of short-lived temperate sceloporine lizards. Ecologically, S. scalaris is a habitat specialist and is dependent on the dense bunch grass not only for shelter from predators but also for the favorable physical conditions especially during winter months. Lizards in more open or exposed sites had lower body temperatures (Smith, et al., 1993). Higher population densities in the Chiricahua Mountains were concentrated in areas with about 90% grass cover of Blephroneuron tricholepsis, Muhlenbergia virescens, and Bromus frondosus (Ballinger and Congdon, 1981). We have observed this species in similar areas of bunch grass in the high plateau grasslands south of Animas, New Mexico (Barney Tomberlin, pers. corn.) Since our studies in the late 1970s and 1980s, cattle grazing in the Coronado National Forest of the Chiricahua Mountains has altered the habitat in which Sceloporus scalaris occurs. The purpose of this note is to call attention to the drastic impact which this management practice has had on this species. Additional work is needed to quantify the extent and severity of the impact.

SREL Reprint #2089

Ballinger, R.E. and J.D. Congdon. 1996. Status of the bunch grass lizard Sceloporus scalaris, in the Chiricahua Mountains of southeastern Arizona. Bulletin of the Maryland Herpetological Society 32:67-69.

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