296 
Marcellini 
Table 2. Comparison of call parameters for 9 species and subspecies of geckos. 
Species and Subspecies* 
(Number of vocalizations) 
Number of Chirps Dominant Frequency 
Mean (Range) From Sonagrams Hz 
Mean Call Rate 
Chirps Per Second 
Hemidactylus frenatus (143) 
9 (5-15) 
1000-2000 
4.51 
H. turcicus (7) 
13 (7-17) 
1500-2000 
approx. 3 
Phyllodactylus tuberculosus (10) 
7 (5-9) 
2000-2500 
3.5 
Ptenopus garrulus (262) 
6 (3-9) 
3000-4000 
5.5 
P. kochi (27) 
11 (9-16) 
3000-4000 
8.9 
Ptyodactylus hasselquistii guttatus $ ^ 
(13) 12 (11-14) 
3000-4000 
1.2 
P. hasselquistii guttatus J (5) 
9 
4000-6000 
slower than ^ A ^ 
P. hasselquistii puiseuxi -f- 5 (7) 
5 (2-9) 
4000-6000 
1.5 
Gekko gecko (3) 
(9-10) 
500-2000 
0.6 
* Hemidactyhis, Gekko and Phyllodactylus data from author, Ptenopus data from Haacke, 1969 and Ptyodactylua 
data from Frankenberg, 1974. 
Table 3. Responses of female Hermdactylus frenatus 
to a recorded male call with statistical evaluation 
of results. 
Responses 
Toward 
Away 
No Choice 
1 
7 
4 
8 
2 
4 
8 
6 
1 + 2 
11 
12 
14 
Table 4. Responses of male HemAdactylua frenatus 
to a recorded male call and to white noise with 
statistical evaluation of results. 
Experiment 
Responses 
Male Call 
Toward 
Away 
No Choice 
Trial 1 
4 
12* 
2 
Trial 2 
6 
12 
1 + 2 
10 
24** 
2 
White Noise 
Toward 
Away 
No Choice 
Trial 1 
6 
8 
3 
Trial 2 
6 
7 
2 
1 + 2 
12 
16 
6 
♦ Significant deviation 
from expected; 
P<0.06 
** Significant deviation 
from expected; 
P<0.26 
in nocturnal 
lizards 
has resulted 
in a de- 
pendence on 
acoustic displays 
in many 
species of geckos. Diurnal geckos are be- 
lieved to have evolved from nocturnal forms 
(Underwood, 1954; Kluge, 1967) and have 
secondarily reverted to visual displays, in- 
cluding posturing and head movements 
(Kastle, 1964). 
Table 5 compares visual displays of the 
iguanid lizards, Anolis nebulosis and Uta 
stansburiana, and the vocal displays of a 
gecko, Hemidactylus frenatus. The two 
iguanids were chosen because their display 
behavior is well known and they appear to 
represent extremes in complexity of iguanid 
lizard display behavior. 
It is my supposition that the behaviors of 
the two iguanids are contextually similar and 
that some of the same things are being ac- 
complished by the displays, the difference 
being that Anolis seems to exercise more 
variety and utilizes an additional part of its 
body (dewlap) in its displays. Allowing for 
such disparities, we may compare the con- 
textual and functional similarities between 
visual and acoustic displays. 
The single chirp has no apparent analog 
in visual displays, but, as discussed previ- 
ously, nongekkonid lizards are known to pro- 
duce squeaks when threatened or handled 
roughly, demonstrating a similarity with 
geckos in this behavior. 
The churr call of H. frenatus has been 
shown to be associated with high-intensity 
aggressive encounters. At first, it might ap- 
pear to function as a challenge display, but 
it is only used when an attack is occurring 
and not at a distance. The churr may func- 
tion as an acoustic component of the aggres- 
