1981] Mac Kay — Nest Phenologies of Pogonomyrmex 
59 
kcals, a P. subnitidus nest 1267.0 kcals, and a P. rugosus nest 7613.6 
kcals of food during a year (MacKay 1981). Of these amounts, a P. 
rugosus colony discards seed husks and other such materials, a 
quantity consisting of 5004.5 kcals or 65.7% of the intake. This is 
indicated in the field by large discard piles of seed husks being 
deposited around the nests. A few seeds are discarded and germinate 
from the piles in the spring. Another harvester ant, Veromessor 
pergandei (Mayr) forages in the piles and removes many of the 
discarded seeds. Pogonomyrmex montanus and P. subnitidus 
discard few materials, the amounts are too small to be estimated. 
Seed storage. 
Seasonal changes in seed storage in P. subnitidus and P. rugosus 
are shown on Figure 14. Pogonomyrmex rugosus began both 1979 
and 1980 (data for January) with 0.04^0.06 grams of seed storage 
per ant. The correlation of ant number vs. seed weight was very high 
(r = 0.997, p < 0.01). This amount dropped until May, possibly the 
Figure 14. A comparison of the seasonal changes of seed storage in P. rugosus 
and P. subnitidus. 
