1981] 
Droual & Topoff— Genus Pheidole 
137 
Table 2. Emigration characteristics of P. desertorum. 
Colony 
Days 
Observed 
Number of 
Emigrations 
Returns to a 
Former Nest 
Distance Between First 
and Last Observed 
Nests (m) 
D-JnlO-la* 
70 
4 
2 
0.5 
D-Jnll-la 
63 
7 
3 
4.8 
D-Jnl l-2a 
68 
0 
0 
- 
D-Jnl2-la 
60 
4 
1 
15.6 
D-Jnl2-2a 
68 
1 
0 
2.5 
D-Jnl2-3a 
68 
2 
1 
0.0 
D-Jnl2-4a 
64 
6 
3 
3.0 
D-Jnl2-5a 
21 
1 
0 
4.2 
D-Jnl3-la 
57 
2 
1 
0.0 
D-Jnl4-la 
61 
3 
2 
0.0 
D-Jnl5-la 
65 
6 
3 
6.6 
D-Jnl5-2a 
62 
3 
1 
0.0 
D-Jnl6-1 b 
64 
4 
3 
0.0 
D-Jnl7-1 b 
57 
4 
2 
0.0 
D-Jnl7-2b 
63 
5 
3 
2.4 
D-Jnl8-la 
49 
3 
1 
3.1 
D-Jn20-1 b 
57 
8 
6 
0.0 
D-Jn25-la 
55 
7 
4 
1.5 
D-Jn28-la 
50 
5 
3 
3.7 
D-Jl 1-la 
42 
7 
3 
2.4 
D-Jl 13-lb 
37 
2 
1 
0.0 
D-Jl 13-2b 
37 
3 
1 
1.2 
D-Jl 15-lb 
33 
4 
1 
0.0 
D-Jl 30-lb 
20 
6 
3 
0.0 
D-Jl 30-2a 
19 
2 
1 
0.0 
D-A 1-la 
18 
2 
0 
4.0 
Total 
101 
49 
*a: desert-grassland; b: oak-juniper woodland. 
observed leaving the nest during a 1 min period. If this criterion was 
not met, or if there was some other reason to doubt the location of 
the colony, a small peanut butter bait was used to locate the colony. 
To avoid confusion when using this indirect method, an attempt was 
made to locate and mark any neighboring conspecific colonies. The 
remainder of the emigrations were observed directly when an 
emigration was discovered in progress. The nests were marked and 
the distance between the old and the new nests measured. 
With the statistical tests employed in this paper probabilities of 
.05 or less were accepted as significant. 
