Psychobiology of Lizard Reproduction 
167 
be sexually receptive if the female’s cloaca 
was covered with tape, thereby preventing 
intromission by the male. 
To investigate this phenomenon experi- 
mentally, I conducted an experiment to de- 
termine (a) whether mating inhibits further 
sexual receptivity within each follicular 
cycle, (b) how rapidly the transition from 
sexual receptivity to nonreceptivity occurs 
following successful copulation, and (c) what 
the critical stimuli that inhibit sexual re- 
ceptivity are (Crews, 1973c). 
To answer these questions, sexually recep- 
tive female A. carolinensis were retested 
for receptivity either 24 hours, 6 hours, 3-5 
minutes, or less than 1 minute following 
either (1) normal copulation with a sexually 
active male or (2) after a male was allowed 
to approach and mount, but not allowed to 
assume the copulation posture or achieve 
intromission. A third group of females was 
initially exposed to hemipenectomized males 
which were allowed to court and assume the 
copulation posture but, because their hemi- 
penes had been removed, could not intromit. 
The results were conclusive. While all the 
females which were just courted and 
mounted by the male remained receptive to 
male courtship, none of the females that com- 
pleted copulation was sexually receptive 
when retested 24 hours, 6 hours, or 3-5 
minutes later (Table 4). Of the 12 females 
retested within 1 minute following separa- 
tion from the male, three were still sexually 
receptive. It should be noted, however, that, 
in these three instances, copulation was in- 
complete due to interruption and premature 
separation of the male; all three females 
ceased to be receptive when allowed to copu- 
late undisturbed. Finally, all seven females 
tested with the hemipenectomized males were 
sexually receptive upon retest 3-5 minutes 
later. 
Hemipenectomy also had an interesting 
effect upon the male. Although the hemi- 
penectomized males courted normally, they 
copulated significantly longer, often failed 
to maintain cloacal contact throughout mat- 
ing despite their proper orientation, and 
never initiated separation from the female. 
Table 4. Number of female Anolis caro- 
linensis still sexually receptive after vary- 
ing intervals following exposure to either 
males that were allowed to court and mate 
with the female (Complete Copulation), 
males that were allowed to court and take 
the neck grip and mount, but not intromit 
(Courtship), or hemipenectomized males 
that displayed all aspects of normal mating 
behavior but could not intromit or ejacu- 
late ( Hemipenectomy ) . 
Group 
n 
Number 
Receptive 
Complete 
Copulation : 
24 hours 
12 
0 
6 hours 
6 
0 
3-5 minutes 
12 
0 
<1 minute 
12 
3 
Courtship : 
24 hours 
12 
12 
6 hours 
6 
6 
3-5 minutes 
12 
12 
< 1 minute 
12 
12 
Hemipenectomy : 
3-5 minutes 
7 
7 
This suggests that sensory feedback from 
the hemipenis during intromission and/or 
ejaculation plays an important role in the 
maintanence and termination of copulation 
in the male. 
There is good reason to believe that this 
coition-induced inhibition of female sexual 
receptivity may be an adaptation peculiar to 
the anoline mating pattern. Female A. caro- 
linensis tend to mate with the male in whose 
territory they have their home range. In the 
natural habitat, mating usually occurs in 
exposed areas such as tree trunks, fences, 
and walls. During this time, the copulating 
pair is particularly vulnerable to predators 
since they can be approached and touched 
without immediately separating. This is pre- 
sumably due to the male’s inability to dis- 
engage himself rapidly from the female once 
