Discussion 
333 
a system is for being cryptic and displaying 
at the same time. 
G. FERGUSON: Yes, one needs to con- 
sider other aspects of crypticity and factor 
these out, if possible. 
RAND: Are there the same number of 
predators in the two types of areas? 
G. FERGUSON: Probably not. 
RAND: That will need to be factored out 
too. 
G. FERGUSON: If one works in the inter- 
grade zones of Utd where there are patches 
of high and low visibility habitat fairly close 
to each other, the number of predators might 
be roughly equivalent for the two areas and 
the same ones might be searching both types 
of habitat. 
CREWS: Let me see if I understand your 
idea. You got a correlation between visibility 
in the habitat and complexity of the display, 
right? Because redundancy insures recogni- 
tion of the conspecific, it follows that the 
animal has to see only part of the display 
to recognize a conspecific, recognize an indi- 
vidual, or be aroused to a certain “motiva- 
tional state.” Why would an animal use a 
complex display? Why not just do a series 
of very simple displays? 
G. FERGUSON: In low visibility a lizard 
is unlikely to see an entire display. 
RAND : As Gary alluded to originally, in an 
area with a lot of vegetation, there is a lot 
of leaf movement, stick movement, much of 
which is oscillatory, O.K.? If you want a 
display that can be picked out easily by a 
conspecific but at the same time you don’t 
want a predator to recognize it, you want 
the display to be within the range of move- 
ments of the vegetation so that you are not 
recognized as something else. This is the 
argument put forth for stick insects, etc. 
But you want to be recognized by a conspe- 
cific so you pick a display that is stereotyped 
and in which the movements are somehow 
different. A simple display won’t do it, be- 
cause you are more likely to duplicate some- 
thing that a leaf is doing. With a more 
complex display you are more likely to be 
doing something unique. 
GANS: If another animal sees only part of 
a display, it can move around to see the 
whole display next time. But the thing that 
Rand mentioned is quite important to me 
because I have been watching tree snakes 
and they move only when the branches are 
moving. If a little wind comes up, here goes 
the Ahaetulla through the branches. As soon 
as the wind stops, the Ahaetulla stops and the 
next time the wind picks up you get another 
curious weaving movement. During every 
movement of the forepart of the body, a loop 
forms behind the head and it just moves 
another few inches. Then, the head stops as 
the wind stops. That kind of blending into 
the background must be exceedingly critical 
in recognition so what you want to do is to 
put some kind of a specific code into the 
middle. But, I’m not concerned about the 
conspecific not seeing the whole signal be- 
cause he can move around and orient to get 
the rest of it. 
CREWS: Has anyone figured out what the 
probability is of a lizard displaying a second 
time after it has displayed once ? 
JENSSEN. Anolis limifrons lives in the 
deeper forest and has a long, complex, often 
repeated display. Anolis nebulosus lives in 
deciduous oak where there is more of an open 
habitat. The display is shorter and not re- 
peated as often. 
RUIBAL: A number of times in the dis- 
cussion the implication has been that this 
display is used for recognition of a con- 
specific. In the case of Uta they must have 
terrible vision if they need a display to dis- 
tinguish another Uta from other lizards. It 
seems that there is a very low probability 
that a Uta would ever confuse another lizard 
with a Uta because they are so different in 
other characteristics. 
G. FERGUSON: You are talking about 
distance, too. At close range there would be 
no problem, but further away there might 
be. 
RAND: I have suggested that the display 
is not used to distinguish a conspecific from 
other species but from other movements in 
the environment. There is much more in an 
assertion display than species recognition 
