Psychobiology of Lizard Reproduction 
163 
Figure 11. Patterns of environmentally induced ovarian recrudescence exhibited by winter-dormant Anolis 
carolinensis exposed to different stimulus males. Sample sizes shown by each point (redrawn from Crews, 
1975a). 
vironmentally induced OR; this hypothesis, 
I submit, has application to other seasonally 
breeding vertebrates as well. 
Several herpetologists have suggested that 
in seasonally active reptiles, A. carolinensis 
included, the males emerge from winter dor- 
mancy, establish territories, and are in breed- 
ing condition before the females emerge. 
Similarly, ornithologists have long noted that 
in many seasonally active passerine species, 
the males arrive at the breeding grounds 
before the females and are in a more ad- 
vanced reproductive state. 
If we assume that these sex differences in 
spring emergence act to insure the presence 
of territory-holding, reproductively active 
males at a time when the females are emerg- 
ing, then it is clearly adaptive for females 
to remain dormant while there is this high 
incidence of aggressive behavior among males 
establishing their territories. It has been 
reported that this aggression between males 
