Bioenergetics of the Great Basin pocket mouse, Perognathus parvus

Abstract

Ingestion rates and annual energy expenditure for the Great Basin pocket mouse, Perognathus parvus, were studied ,in south-central Washington (Hanford Reservation) during 1970-71 as part of the US/IBP Desert Biome program. Food intake models were derived in relation to time, microenvironmental temperatures, metabolic rate, and coefficient of digestibility. Estimated annual ingestion rates were 2550 and 2462 kcal/yr for individual males and females, respectively. Summer torpor reduces these costs about 3%. Winter energy expenditure was 40-43% lower than summer because of more extensive periods of torpor. Estimated daily maintenance energy requirements ranged from a low of 2.36 and 2.63 kcal in the winter to a high of 6.96 and 6.55 kcal in the spring for individual adult males and females, respectively. These estimates indicate P. parvus consumes between 4-10% of its body weight in food per day during the year. Assuming a diet consisting entirely of cheatgrass seeds (Bromus tectorum), individuals require 873-999 seeds per day in the spring and summer, decreasing to about 775 seeds per day in the fall. In the winter, facultative torpor reduces this to less than 400 seeds per day, necessitating the caching of approximately 50-65 g of seeds. The average annual seed crop would support a maximum density of about 80 animals/ha, indicating this granivore may be periodically food stressed. The overall impact of P. parvus on plant succession at the Hanford site is probably ¡minor.[Dept. Biol. Sci., Univ. Idaho, Moscow, Idaho 83843, USA].

Granivores, exclosures, and seed banks: harvester ants and rodents in sagebrush-steppe

“…Peromyscus maniculatus is an omnivore, with seasonally changing proportions of seeds, arthropods, and green vegetation in its diet (Williams, 1959;Chew & Chew, 1970;Parmenter & MacMahon, 1983). Perognathus parvus tends to eat insects during the spring, switching to seeds later in the year (Flake, 1973;Schreiber, 1978). Tamias minimus eats mostly plant material including seeds, some arthropods, a few birds' eggs, and some young birds (Banfield, 1974;Clark & Stromberg, 1987).…”

Group effects of a non‐native plant invasion on rodent abundance

“…). Though the pocket mice species we investigated also engage in scatter‐hoarding and can hoard and consume cheatgrass seeds (Schreiber ) our findings suggest these species do not benefit from cheatgrass establishment in this system. Chisel‐toothed kangaroo rats were likely not able to confer the same benefits of cheatgrass as Ord's kangaroo rats because they are primarily folivores, though this species does possess the ability to supplement their diet with seeds (Hayssen , Jenkins and Breck ).…”

Biology of the Heteromyidae

“…Indeed, with only one exception, desert heteromyids are primarily granivorous, although their diets can reflect seasonal availability of insects and green vegetation (Alcoze and Zimmerman, 1971;Best and Hoditschek, 1982;Bradley and Mauer, 1971;Brand, 1975;Chapman, 1972;Chew and Chew, 1970;Dunham, 1968;Flake, 1973;Hawbecker, 1940: Holdenreid, 1957Kritzman, 1974;LaTourette, 1971;M'Closkey, 1980;Meserve, 1976;O'Connell, 1979;Reichman, , 1978Reynolds, , 1960Schreiber, 1978;Shaw, 1934;Smigel and Rosenzweig, 1974;Smith, 1942;Soholt, , 1977Stamp and Ohmart, 1978;Tappe, 1941;Vorhies and Taylor, 1922). In keeping with their small gape, the seeds used by desert heteromyids tend to be small (less than 3 mm in length and less than 25 mg) and primarily from grasses or forbs Reichman, , 1976Reichman, , 1978.…”