Tiny rodents sabotage landfill restoration

Efforts to transform New York landfills into parks are being thwarted by an adorable but destructive pest: the vole.

Landfills are prime sites for wildlife restoration. There are more than 3,500 landfills in the United States, and they can degrade water supplies and harbor pests that spread diseases. With re-planting, however, landfills can become oases for trees, shrubs, and native animals.

Gary Witmer, a researcher at the USDA National Wildlife Research Center in Fort Collins, Colorado, studied two restored landfills in Long Island, New York. The landfills had been covered with soil and planted with grasses, forbs, shrubs, and trees.

At each site, Witmer tried a variety of methods to keep pests away, including rodenticide, mowing, and pea gravel. Then he monitored the seedlings’ growth for about seven months, noting damage to stems, branches, and roots. Witmer also set traps containing peanut butter, oatmeal, and apple to attract rodents and looked for tell-tale signs of the animals, such as feces and burrows.

At each plot, about 40 to 73 percent of the seedlings died or were damaged, he reports in Restoration Ecology. Witmer caught 441 rodents in the traps, and 71 percent of the critters were voles. Rabbits were responsible for less than 5 percent of the seedling damage, he estimates.

Seedlings surrounded by pea gravel barriers fared slightly better: About 39 percent were damaged and only 1 percent died. But managers might need to control the voles with rodenticides or traps as well to give the plants a fighting chance.Roberta Kwok | 16 October 2013

Source: Witmer, G.W. 2013. Evaluating habitat manipulations and rodenticides to protect seedlings from rodent damage at restored landfills in New York. Restoration Ecology doi: 10.1111/rec.12056.

Image © Rui Saraiva | Shutterstock