270 
Jenssen 
Besides the diversity in morphology and 
physiology that accompanies the adaptation 
to diverse habitats, anoles also demonstrate 
diverse behavioral characteristics. Research- 
ers are discovering that anoline social struc- 
ture can take many forms. Anolis agassizi 
has a nonterritorial organization based on 
loose dominance hierarchies (Rand et al., 
1975) that may be related to its habitat on 
Isla Malpelo, a small rocky outcropping in 
the Pacific, "where food resources are local- 
ized and unpredictable. As regards Jamaica’s 
Anolis valencienni, while the females are 
free-ranging and nonterritorial, the males 
are weakly territorial (Trivers, MS). In the 
Lesser Antilles, male A. aeneiis can defend 
areas large enough to accommodate as many 
as 12 females; these females are territorial 
toward members of their own sex, but when 
their densities increase within a male’s ter- 
ritory, the females form dominance hier- 
archies (Stamps, 1973). In the Mexican A. 
nehulosus, whose adult sex ratio is more 
nearly equal than that of A. aeneus, male 
territories are small and contain no more 
than two territorial females (Jenssen, 1970). 
There is evidence that large adult A. limi- 
frons females in Panama may be solitary 
and occupy territories which are exclusive 
of permanent male residents (Jenssen, in 
press). 
METHODS 
Observations and Documentation 
I usually begin a study by working with 
lab-held animals, since the highest quality 
films or videotape recordings of displaying 
lizards are achieved in the laboratory. 
In maintaining laboratory populations, I 
keep low densities of animals in relatively 
large holding cages. These enclosures contain 
a reasonable facsimile of the species’ natural 
micro-habitat (e.g. grass and twigs for grass 
anoles ; stumps, horizontal branches, and 
foliage for arboreal species). I find a dense 
habitat is valuable as it shortens line of 
sight and decreases interactions between 
dominant and subordinate lizards. Several 
food and water dishes are placed on elevated 
sites around the enclosure to counter the 
reluctance of subordinate lizards to seek 
food and water. 
In recording displays, I work from a blind 
because many of the anoline species are shy 
and their behavior is affected by the presence 
of an observer. The filming enclosure is large, 
contains simulated natural habitat, and is 
fitted with a slanting glass front to decrease 
the chance that the lizard will react to its 
own reflection. Heat-filtered floodlights are 
used not only for photographic purposes, but 
for stimulating increased activity in the 
lizards. Various combinations of conspecifics 
are placed in the enclosure so as to evoke 
different types of displays. 
To elicit aggressive encounters between 
males or between females, I allow a lizard to 
establish residency of several days in the 
enclosure. Then I release another lizard of 
the same size and sex into the enclosure. The 
ensuing response is usually short-lived, with 
the resident the victor. Another technique 
which more closely simulates natural condi- 
tions utilizes a long, partitioned enclosure 
(Fig. 1) with similar habitats in each of its 
far ends. With the partition in place, I re- 
lease male and female pairs into each half of 
the enclosure. Recordings are made of the 
kinds of displays and their frequency of oc- 
currence. After a day or more the partition 
Figure 1. Enclosure used in partition experiments. 
