Status of the parthenogenetic lizards of the Cnemidophorus laredoensis complex in Texas: Re-survey after eleven years

During the 1980s, extensive field work was conducted to clarified the distr ibution of the two species (one undescribed) of the parthenogenetic Cnemido phorus laredoensis complex of lizards. The two species, designated LAR-A an d LAR-B, were found either singly or together at 37 sites in Texas; most of these sites were also occupied by the bisexual (gonochoristic) species Cne midophorus gularis. The majority of these: sites were re-surveyed from Marc h through May 2000 to ascertain what changes in lizard population compositi on and habitat had occurred since the last extensive survey ended in 1989. The data revealed three broad trends. First, sites in large cities were oft en substantially altered or completely destroyed by development, resulting in dramatic decline or complete extirpation of lizards. Second, the bisexua l species C. gularis has expanded its range into many sites that previously had been occupied only by parthenogens. Third, while LAR-A populations rem ained stable, LAR-B populations appeared to decline since the 1980s. The pr olonged drought in southern Texas during the 1990s is one possible explanat ion of this decline.