240 
Ferguson & Bohlen 
Table 10 
Overlap of iguanid fauna : 
A. Iguanid lizard species sympatric with Uta in each of seven zones of 
push-up similarity. Plus in a column indicates presence of a given species 
in that geographic zone. 
Geographic zones of push-up 
Small iguanid species 
similarity in Uta 
sympatric with Uta 
1 
2 
3 
4 5 6 7 
Uroscmrus graciosus 
+ 
+ 
Urosaurus ornatus 
Urosaurus microscutatus 
+ 
+ 
Sceloporus magister 
+ 
+ 
+ 
+ 
Sceloporus undidatus 
+ 
Sceloporus graciosus 
+ 
+ 
+ 
Sceloporus occidentalis 
Sceloporus clarki 
+ 
+ 
+ 
+ 
Sceloporus orcutti 
+ + 
Sceloporus linestulus 
Callisaurus dracionoides 
+ 
+ 
4- 
+ 
Holbrookia maculata 
+ 
Holbrookia texana 
+ 
Uma 
Streptosaurus mea/msi 
+ 
+ 
+ 
B. Percent overlap of iguanid fauna between zones. P=100[c/(a-|-6)], 
where P=percent overlap, a=number of species inhabiting zone a, 
&=number of species inhabiting zone b, c= number of species inhabiting 
both zones a and b. 
Zones 
following reasons : If the predator is a 
bird, it will be searching a larger area than 
that of the conspecific lizard and will prob- 
ably be farther away from the displaying 
lizard than the conspecific lizard. If the pred- 
ator is a snake, it will also be searching a 
larger area, but at the same ground level, 
being alert for lizards, other snakes, and 
small mammals as potential food items. 
In a more heavily vegetated habitat, both 
simple and complex displays would be less 
likely to be detected by the wandering type of 
predators described above. Lizards perform- 
ing simple displays with a background of 
moying grass or foliage might be harder for 
conspecifics to detect than lizards performing 
more complex displays that are distinct from 
random movements of vegetation. In sum- 
