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There were significant variations in how many caches of buried Indian rice grass (Oryzopsis hymenoides) seeds were found by Dipodomys microps, Dipodomys ordii, Microdipodops megacephalus, Perognuthus formosus, Perognathus longimembris, Perognathus parvus, Peromyscus maniculatus, and Reithrodonotomys megalotis. Success ranged from that of P. manicuiatus and R. megalotis, that failed to find any buried seeds in dry sand, to P. formosus, that found 57.5% of the seeds buried at 0.6 cm, to M. megacephalus that found 50% buried 1.3 cm deep. Peromyscus maniculatus and P. parvus found more buried seeds as The authors are graduate student and professor of

Leafy twigs and seeds of juniper are abundant in nine ancient Neotoma middens discovered in low, arid, desert ranges devoid of junipers, near Frenchman Flat, Nevada. Existing vegetation is creosote bush and other desert shrubs. Twelve radiocarbon dates suggest that the middens were deposited between 7800 to more than 40,000 years ago. Dominance of Utah juniper and absence of pinyon pine in most deposits indicates a local Pleistocene woodland climate more arid than the usual pinyon-juniper climate.

Harvester ant colonies (Pogo~omy~ex owyke~ Cole) in southern Idaho were monitored periodically for 9 years. Mortality rates indicate that established colonies live 1430 years 6 = 17). Mounds were commonly reactivated after the death of an old colony; consequently, some may be utilized for many decades. Clearings with active mounds showed almost no change after 9 years of observations while those without nctive mounds were rapidly filled by annual herbs and then gradually by perennial shrubs. Harvester ants are clearly 8 very persistent component of cold desert shrub communities. but needing improvement (Burley District, BLM). we mltially mapped P. owyheei mounds at 3 small plots (0.25 ha) and 1 large plot (2.72 ha, Fig. 1) in 1977. Mounds and clearings 0 : : Main iPlot 0. 4.:. j o ; .

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