Global Short Term Trend: Relatively stable to decline of 30%
Comments: This species apparently has declined in area of occupancy and population size near the northeastern margins of the range in Texas, Oklahoma, and Kansas, but it is doing well in most the range. According to Price (1990), the Texas horned lizard has virtually disappeared from Texas east of a line from Fort Worth through Austin and San Antonio to Corpus Cristi (formerly widespread and abundant in that area); it has also declined in range and/or abundance in areas where it was formerly common in parts of north-central Texas, the Texas Panhandle, and parts of Oklahoma. Price's conclusions are supported by more recent surveys in Texas, Oklahoma, and Kansas. A 1992 Texas survey found the greatest declines in east Texas (where no individuals were found) and apparent declines also in central Texas; the species appeared to be doing well in northern and western Texas (Donaldson et al. 1994). Bartlett and Bartlett (1999) stated that the decline may have halted in at least some parts of Texas; they found numerous individuals in areas where searches in several previous years yielded few. A 1999 survey in Texas was unable to determine if the decline has halted or if it continues today (Henke 2003). A 1992 Oklahoma survey found the species to be rapidly disappearing in eastern areas of Oklahoma where it was once known to be abundant (Carpenter et al. 1993). A 1993 survey of the northern Flint Hills of Kansas suggested that populations were possibly declining (Busby and Parmalee 1996), and local collectors reported declines in the southeastern portions of Kansas (Bill Busby, pers. comm., 1998). In Colorado no trend information is available, but recent surveys indicate that the species appears to be locally common and stable (Siemers, pers. comm., 1998; Hammerson 1999). According to Rosen (Herp Diversity Review 1996), populations are thriving and plentiful in extreme southeastern Arizona. New Mexico densities have not changed historically, and populations are considered stable (Charles Painter, pers. comm., 1998). Status is unknown in Sonora, Mexico (Andres Villareal Lizarraga, pers. comm., 1998).
Global Long Term Trend: Relatively stable to decline of 50%