1^3 



above ground increased in each enclosure, aggression levels increased 

 significantly in _C. sexlineatus groups containing males. Above ground 

 activity in all species groups peaked in late morning to early after- 

 noon. Nepotistic behavior was never observed among parthenogenetic liz- 

 ards for several possible reasons. First, members of parthenogenetic 

 populations may not be genetically identical due to independent origin 

 of clones, mutation and/or recombination. Second, because these species 

 are hybrids between two or three bisexual species, they may contain gene 

 combinations that result in competitive rather than cooperative beha- 

 vior. Third, whiptail species do not defend resources, so opportunities 

 for sharing or sacrificing resources are low (from abstract). 



115. — . 1982. Comparative burrow use and activity patterns of par- 

 thenogenetic and bisexual whiptail lizards (Cnemidophorus ; Teiidae). 

 COPEIA 1982(2): ^16-^^2^. 



A portion of the preceding study. _C. sexlineatus and diploid _C. 

 tesselatus used were collected at Conchas Lake State Park, San Miguel 

 Co., New Mexico, triploid _C_. tesselatus from near Florence, Fremont 

 Co., Colorado, and C. neomexicanus from Albuquerque, Bernalillo Co., 

 New Mexico. Behavior for groups of conspecifics was quantified in out- 

 door enclosures. Burrows could be dug under 6 objects in an enclosure, 

 along the walls or in open sand. Objects were not equally utilized by 

 any group except female _C. sexlineatus . _C. tesselatus constructed bur- 

 rows in open sand more frequently than other groups; all the partheno- 

 species used burrows significantly more than the bisexual groups. 59% 

 of all unisexual lizards observed burrowing used 3-6 sites whereas only 

 ^% of all bisexual lizards seen used more than 2. The lack of site- 

 specificity in the parthenogens is related not only to their genetic 

 similarity to conspecifics but also to their propensity for disturbed 

 habitats where environmental fluctuations are constantly destroying 

 burrows. 20% of all _C, tesselatus burrowed in open sand, whereas only 

 6% of the_C. neomexicanus and 13% of all _C. sexlineatus did. Of the 9 

 instances of burrow sharing between parthenogens, 8 occurred in _C. tes- 

 selatus groups (4 2N and ^ 3N). Burrow sharing is attributed to toler- 

 ance rather than cooperation. Burrow sites were not defended nor were 

 particular objects monopolized or controlled by high-ranking lizards of 

 any species group. No differences between bisexuals and parthenogens 

 were detected in activity parameters measured. _C. neomexicanus was 

 more aggressive than _C. tesselatus , but aggression was highest in 

 groups containing male _C. sexlineatus . It is concluded that coopera- 

 tion does not occur between parthenogens, but tolerance for conspe- 

 cifics is higher than that of bisexuals. The greater incidence of bur- 

 row sharing between parthenogens (8 instances in 75 lizards observed 

 versus 1 in 75) is presented as support for kin selection theory. No 

 other variable measured (time of activity, habitat use, defence of re- 

 sources or aggressive behavior) differed between the species in rela- 

 tion to their reproductive mode. 



