Rodents Help Seed the Range

Kangaroo rats help an important western native plant more than researchers have realized. The small rodents stash thousands of Indian ricegrass seeds underground on late spring or summer nights, but often don't return for the tasty meal. Many of these overlooked seeds sprout the following spring to yield hardy plants that provide nutritious forage for cattle and wildlife.

Federal researchers now give kangaroo rats and their relatives, such as pocket mice, more than 90 percent of the credit for Indian ricegrass seedlings that sprout and take hold on the desert ranges of California, Utah and Nevada. The figure comes from a recent 4-year-study of wildlife that feed on seeds of key rangeland plants.

Animal ecologist William S. Longland of the Agricultural Research Service led the investigation. He's at ARS' Ecology of Temperate Desert Rangelands Laboratory in Reno, Nev.

A kangaroo rat gathers hundreds of seeds at a time in its fur-lined cheek pouches, then buries them in shallow hiding places or caches. The "planting depth" is ideal for Indian ricegrass, and the caches also protect the seeds from ants and other would-be poachers, including other rodents.

While rooting for the kangaroo rat in this case, Longland and colleagues also devise strategies to outwit it and other wildlife that eat seeds planted by land management agencies or ranchers. Earlier experiments led by Reno laboratory director James A. Young and Longland showed that planting fewer seeds--but deeper and farther apart than traditional rangeland seeding operations--seems to deter rodents by making them work too hard for their meal.

An article in the January issue of ARS' Agricultural Researchmagazine tells more. The article is also on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/jan98/rats0198.htm

Scientific contact: William S. Longland, USDA-ARS Ecology of Temperate Desert Rangelands Laboratory, 920 Valley Rd., Reno, NV 89512, phone (702) 784-6057, fax (702) 784-1712, [email protected].