82 



sexual reproduction within these parthenoforms. It is suggested that 

 they were derived parthenogenetically rather than being of hybrid 

 origin. The presence of males proves that vestiges of bisexuality are 

 retained within these parthenospecies and their scarcity may indicate 

 that the evolution of parthenogenesis has reached an advanced stage. 



223. Tinkle, D. W. 1959. Observations on the lizards Cnemidophorus 

 tigris , Cnemidophorus tessellatus and Crotaphytus wislizeni. SOUTH- 

 WESTERN NATURALIST i^W: 195-200. 



It is suggested that the disjunct distribution of _C. tessellatus 

 in the west Texas panhandle is due to competition with _C. tigris or _C. 

 gularis , as suitable habitat is present. The absence of males of the 

 species in museum collections is noted. Size distribution of specimens 

 indicates that most will not reach reproductive maturity until their 

 second spring after birth. _C. tigris marmoratus appears to be extend- 

 ing its range east of the Pecos River and into the caprock area below 

 the high plains of northwest Texas. Reproductive maturity for both 

 sexes is not reached until the second spring after birth, and the size 

 at maturity is significantly smaller than that for C_. tessellatus . 



22*. Turner, F. B. and C. S. Gist. 1965. Influences of a thermonu- 

 clear cratering test on close-in populations of lizards. ECOLOGY '^6 

 (6): 845-852. 



Pre- and post-test densities of Cnemidophorus tigris are given 

 for the blast which occurred on 6 July 1962. Descriptions of the habi- 

 tat, nuclear device, physical damage and radiation dosages are given. 

 Adults were exterminated to a distance of ^+000 feet from ground zero. 

 No changes attributable to the explosion were detected beyond 8500 

 feet. Eggs hatched following the test in areas where adults did not 

 survive. Immediate mortality is attributed to blast effects, delayed 

 mortality to the destruction of habitat. Cnemidophorus may be more 

 susceptible to deleterious effects than Uta . 



225. — , P. A. Medica, J. R. Lannom, 3r. and G. A. Hoddenbach. 



1969. A demographic analysis of fenced populations of the whiptail 

 lizard Cnemidophorus tigris in southern Nevada. SOUTHWESTERN NAT- 

 URALIST 1M2): 189-201. 



Spring densities ranged from 3 to 8 lizards per acre, biomass 

 between i*3-114 gms/acre. The sex ratio was 1:1. Minimal annual adult 

 survival was 5^^-60%; life spans may be as great as 7 years. Most fe- 

 males laid only 1 clutch per year of 2-4 eggs. Sexual maturity was 

 normally reached during an individual's 3rd year (2nd reproductive 

 season). The correlation between reproductive events and population 



