390 
Psyche 
[Vol. 85 
Table I; Order of predation* by the gecko P. h. f^uiiulaius. on a choice of 
grasshoppers. 
serial 
number 
gecko 
normal 
P. syriaca 
male 
silenced 
P. syriaca 
male 
4th instar 
nymph, 
L.m.ni. 
1 
0 
1 
1 
2 
0 
1 
1 
3 
0 
1 
1 
4 
3 
1 
2 
5 
3 
2 
1 
6 
2 
0 
1 
7 
0 
1 
0 
8 
0 
1 
1 
9 
2 
3 
I 
10 
3 
1 
2 
11 
0 
2 
1 
12 
2 
3 
1 
13 
0 
0 
1 
14 
0 
1 
0 
15 
3 
1 
I 
16 
0 
2 
1 
17 
0 
0 
1 
18 
0 
1 
0 
19 
3 
1 
2 
20 
0 
0 
1 
21 
0 
2 
1 
22 
0 
1 
1 
23 
0 
2 
1 
24 
0 
0 
1 
25 
0 
2 
1 
26 
0 
0 
1 
*The numbers 1, 2, and 3 represent order of predation; 0 indicates that the 
grasshopper was alive at the end of the 24 hr test period. The same number for more 
than 1 grasshopper indicates that they were consumed between the same two 
observation periods. 
the untreated P. syriaca in 23 experiments (p^ 0.001) and before 
silenced ones in 14 experiments (p = n.s.). It is therefore concluded 
that the protest sounds produced by P. syriaca apparently reduce 
predation on it by P. h. guttatus. 
Discussion 
To a hungry caged gecko offered a choice between fly maggots 
and grasshoppers, the latter are invariably preferred. However, it is 
