Forest Eaters
About a third of the land on Earth is covered by forests. The benefits of forests are innumerable. These leafy ecosystems are home to millions of different species, absorb carbon and other pollutants form the atmosphere, protect against soil erosion and floods, act as natural air conditioners, reduce human noise pollution and, if that was not enough, provide wood. When a forest is removed through a natural disaster or planned human activities, restoration scientists work hard to speed up the process of reforestation. These large scale efforts, however, must contend with a very small-scale antagonist, the deer mouse.
Deer mice, Peromyscus sp.s, are the most abundant and wide-spread mammals in North America, and they are deceptively cute creatures. They resemble a ping-pong ball of fuzz with two large, dark eyes, big ears and a pink, yarn tail. Adult versions of this pre-school arts-and-crafts project weigh only about 3/4ths of an ounce and are only 4 inches long, tail included. But don’t let their button nose and soft, white bellies deceive you. Deer mice are voracious predators!
In a single night, a captive deer mouse can consume 200-350 seeds. They have a particular taste for conifer seeds. One study attempting to sow pine seeds on 100 acres of deforested land found that in less than a week, deer mice consumed up to 95% of the sown seeds. Making matters worse, deer mice are found in higher numbers in recently deforested areas, such as those affected by wildfires, where foraging becomes easier for the little fuzz balls. Because of all this, foresters often plant pine seedlings instead of seeds.They are also a pest to farmers, and habitually dig up corn, melon and alfalfa seed for a snack.
Stemming this tide of fuzzy seed-munchers takes some doing. There are rodenticides and repellants, but because there are so many mice and it only takes a few to decimate fields of seeds, these approaches have varying rates of success. Another strategy is to divert their appetites by mixing tree seeds in with a food they like better, such as sunflower seeds. It’s the mouse equivalent of spoiling dinner with dessert.
With so many hungry little mouths, it’s a wonder we have any forests at all! It really makes you appreciate the ecological benefits of hawks and snakes.
Brian Rutter, PhD, is the cofounder of Thing in a Pot Productions and a postdoctoral researcher in plant biology at Indiana University. Subscribe to our newsletter to receive our “Things About Things – Odd Facts About Plants” and video production tips in your inbox every month!
Works Cited:
Nolte, Dale L., and James P. Barnett. "A repellent to reduce mouse damage to longleaf pine seed." International Biodeterioration & Biodegradation 45.3-4 (2000): 169-174.
Sullivan, Thomas Priestlay. Conifer seed predation by the deer mouse: a problem in reforestation. Diss. University of British Columbia, 1978.
Timm, Robert M., and Walter E. Howard. "White-footed and deer mice." The Handbook: Prevention and Control of Wildlife Damage (1994): 9.
Witmer, Gary W., and Rachael S. Moulton. "Deer mice (Peromyscus spp.) biology, damage and management: a review." (2012).