136 
Psyche 
[Vol. 88 
Table 1. Emigration characteristics of P. hyatti. 
Colony 
Days 
Observed 
Number of 
Emigrations 
Returns to a 
Former Nest 
Distance Between First 
and Last Observed 
Nests (m) 
H-Jnl4-1 
66 
6 
3 
4.2 
H-Jnl4-2 
66 
16 
1 1 
1.1 
H-Jnl4-3 
66 
8 
2 
5.4 
H-JnI5-l 
23 
1 
0 
1.5 
H-Jnl5-2 
63 
7 
3 
0.0 
H-Jnl7-1 
63 
0 
0 
- 
H-Jnl7-2 
63 
6 
2 
0.8 
H-Jnl8-1 
62 
10 
5 
3.2 
H-Jnl8-2 
55 
7 
2 
6.8 
H-Jnl9-1 
61 
7 
4 
0.0 
H-Jnl9-2 
57 
4 
1 
0.0 
H-Jnl9-3 
61 
6 
2 
1.5 
H-Jnl9-4 
60 
5 
2 
0.0 
H-Jnl9-5 
61 
7 
5 
2.0 
H-Jn21-1 
59 
3 
0 
2.6 
H-Jn21-2 
58 
6 
4 
1.9 
H-Jn21-3 
57 
4 
2 
0.0 
H-Jn21-4 
57 
6 
3 
3.0 
H-Jn23-1 
53 
2 
0 
0.8 
H-Jn24-1 
56 
7 
1 
0.8 
H-Jn26-1 
51 
5 
1 
2.5 
H-Jn26-2 
16 
2 
0 
1.1 
H-Jn27-1 
46 
8 
2 
0.4 
H-Jn28-1 
52 
4 
2 
2.4 
Total 
137 
57 
Colony designations were based on the species (D - desertorum, 
H - hyatti ), the date when the colony was found (Jn - June, J1 - July, 
A - August) and the order in which it was found on that date. For 
example, H-Jnl8-2 is the second P. hyatti colony found on June 18. 
Activity for both species began at approximately 2000 hr (MST) 
and ceased 0500 hr. To determine emigration frequency all colonies 
were inspected at least once daily between 2000 and 2400 hr. In 
order to avoid disturbing the colony any prolonged observations 
were made using red light. About two-thirds of the emigrations for 
each species were documented indirectly when a colony occupying a 
nest one night was found at another nest the following night. A 
colony was assumed to be occupying a nest if 10 foragers were 
