Discussion 
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DISCUSSION 
PETERSON to GREENBERG: Regarding 
naturalistic settings, it is important to real- 
ize that there are some problems that only a 
simplified laboratory setting can deal with. 
For example, natural settings exaggerate the 
possibility that an experimental effect may 
be overlooked. This is because in a complex 
environment the brain can compensate for 
some kinds of deficits, but in an unnatural 
laboratory setting the animal may be com- 
pelled to live in a certain way and this can 
be very revealing. For example, Schneider’s 
tectal lesioned hamsters looked normal in 
some environments but an important deficit 
showed up in others. There is also the pos- 
sibility of misinterpreting a deficit. For ex- 
ample, in 1970 Humphrey (BBE 3:320-337) 
dispelled the old belief that primates with 
striate cortex lesions are blind. In an un- 
natural setting he was able to show that the 
deficit is really one of recognition. 
GREENBERG: your point is good about 
the difficulty of interpreting behavior in com- 
plex settings. The main thing is to have a 
reasonable idea of the normal behavior of the 
animal. Without such an idea you may find 
yourself investing considerable effort in in- 
vestigating a laboratory-induced pathology 
of relatively limited interest. Once a natural- 
istic overview is obtained one could succes- 
sively simplify experimental habitats until 
an appropriate one for the experiment is ob- 
tained. Also, naturalistic observation may 
reveal behavioral patterns that you might 
otherwise be totally ignorant of. 
REGAL to CREWS: This research contrib- 
utes to our understanding of the process of 
sexual selection. I think the difference be- 
tween emergence of males and females might 
relate to the fact that it is to the female’s 
advantage to let the subordinate males get 
“weeded out” so that, when the female finally 
selects a male, it is a male with a superior 
genetic constitution (a territory-holding 
male) who has possibly selected a better 
habitat. In any event, the chosen male has 
won out in some sort of competition and pre- 
sumably would give her superior male off- 
spring, etc. 
CREWS: I believe females are presented 
with two different types of choices in terms 
of sexual selection. First, when the female 
emerges from winter dormancy, she must 
establish a home range; this choice is prob- 
ably determined by a combination of habitat 
preferences and some aspect of the male in 
whose territory she will reside. Second, male 
choice is perhaps more important for the 
transient female who moves about the habi- 
tat. This would be especially important when 
the female has a large, preovulatory ovarian 
follicle — which male does she choose to mate 
with? 
MacLEAN to CREWS: Can you keep ani- 
mals cycling year round with the environ- 
mental conditions you have described? 
CREWS : Female AnoUs carolinensis will 
go through at least three complete ovarian 
cycles (ovarian quiescence, recrudescence, 
breeding, and regression) under this envir- 
onmental regimen in a one-year period. 
Within each reproductive phase, females will 
usually go through at least ten estrous cycles 
and sometimes lay up to 15 eggs before the 
ovaries regress. 
MACLEAN : What other lizards have this 
sort of an estrous cycle ? 
CREWS: Most temperate species that I 
am aware of are single or multiple-clutch 
layers; that is, they only exhibit one or two 
estrous cycles, after each of which they lay a 
clutch of eggs. All anoline lizards, however, 
exhibit the pattern of ovarian activity I 
have described here. 
GARRICK to CREWS: Is there any 
evidence for hormone-brain interactions in 
some of these behaviors that you observed? 
CREWS: We have recently begun an in- 
vestigation of the neural and hormonal deter- 
minants of sexual behavior in reptiles. 
PETERSON: I would like to expand on a 
point raised by Dr. Brattstrom, namely, that 
learning may play a more important role in 
the normal behavior of lizards than has here- 
tofore been suspected. One gets the impres- 
sion, both from remarks made at this con- 
ference and from an examination of the be- 
havioral literature, that data on lizards 
gathered from the learning laboratory are 
