LIFE-HISTORY CHARACTERISTICS OF 3 MORPHOTYPES IN THE PARTHENOGENETIC CNEMIDOPHORUS-DIXONI COMPLEX (SAURIA, TEIIDAE) IN TEXAS AND NEW-MEXICO

We compared life history characteristics of three morphotypes (or patt ern classes A-C) of the parthenogenetic lizard, Cnemidophorus dixoni. A and B were studied in Trans-Pecos Texas from 1989 through 1993; it w as not possible to study C in Hidalgo County, New Mexico. The peak act ivity period for both C. dixoni A and B appeared to be between 1045 an d 1245 Central Daylight Time. No significant differences were found in cloacal body temperature between C. dixoni A and B; however, mean air temperatures at sites of collection were higher for B than for A. C. dixoni C grows to a larger adult body size than either A or B. Populat ions of A and B contain three age classes; C includes either a fourth age class or has a more rapid growth rate. C. dixoni C also has a larg er clutch size than A and B. The population of C. dixoni in western Ne w Mexico is not a disjunct population of B located some 500 kilometers west of Presidio County, Texas. It is a distinctive form worthy of ef forts to insure its survival.