«t2 



110. Kerfoot, W. C. 1969. Selection of an appropriate index for the 

 study of the variability of lizard and snake body scale counts. SYSTE- 

 MATIC ZOOLOGY 18(1): 33-62. 



Previously published data on several species of Cnemidophorus 

 ( exsanguis , flagellicaudus , inornatus , neomexicanus , tesselatus , tigris 

 and uniparens ) are taken to show that variation in several scale counts 

 is much greater in bisexual than parthenogenetic species. 



111. Knopf, G. N. 1966. Reproductive behavior and ecology of the 

 unisexual lizard, Cnemidophorus tesselatus Say. PH.D. DISSERTATION, 

 UNIVERSITY OF COLORADO. Hip. 



Cnemidophorus tesselatus is most abundant in Colorado in arroyos, 

 gullies, and hillsides adjacent to or along river bottoms. It general- 

 ly occurs in abundance locally when and where found, although it may be 

 absent from equally suitable habitat only a few miles away. The area 

 of this particular study is a 2.03 acre site located on bluffs above 

 the Huerfano River in Pueblo County, Colorado, 26.2 mi. SE of Pueblo at 

 an elevation of 5000 feet. It is heavily overgrazed with scant vegeta- 

 tion, and with several man-made topographic features. The summers are 

 hot and the winters generally rigorous. Dominant vegetation consists 

 of Chrysothamnus nauseosus , Opuntia polyacantha , O. arborescens , Sal- 

 sola pestifer and Yucca glauca . Lizards were captured by noosing and 

 drift-fence trapping and permanently marked. Resident lizard behavior 

 varied from fleeing after being noosed once to being noosed 20 or more 

 times with little or no escape reaction upon approach by the nooser. 

 Lizards were seldom trapped more than twice, however, before they 

 "learned" to avoid them. All residents were eventually marked. Li- 

 zards were considered hatchlings, juveniles, subadults or adults if 

 they were 39-^^8, ^^9-66, 67-80, and greater than 80 mm snout-vent length 

 (SVL), respectively. Data for this study is based primarily on the 

 period 18 May-10 September 1965. 87 lizards (16 juvenile, 17 subadult 

 and 5^ adult) were marked between late May and mid-July. 17% were 

 never recaptured; the others were recaptured 1-30 times. 35 hatchlings 

 were captured during the fall. The reproductive cycle is discussed in 

 detail. A single clutch of l-'f eggs was laid during 1965; larger li- 

 zards had larger clutches. Oviducal eggs are retained from 3 days to a 

 week or longer; eggs retained longest require a shorter incubation per- 

 iod. Oviducal eggs were first found 12 June and last found 23 July. 

 Evidence suggests that 2 clutches were produced in 1966; 196^ was one 

 of the driest and 1965 one of the wettest years ever recorded in the 

 Pueblo region. Rapid accumulation of large fat reserves begins after 

 oviposition; most older lizards disappeared by mid-August. There were 

 two peak periods of egg-laying, centered around 20 June and 8 July. 

 The first period involved primarily the oldest and largest members of 

 the population. Adults remain in the underground nests for at least 2 



