Researchers found nearly three times as many red-backed salamanders and five-and-a-half times more snakes in sites with deer than those without deer. Among invertebrates, snails were 11 percent more abundant in grazed areas than in exclosures and the diversity of arthropods was also 14 percent greater in these areas.
Greenwald speculates that the areas with higher deer populations may appear to lack the high variety of low-lying plants found in exclosures, but the deer may be creating a richer soil mixture through their droppings. This rich soil may be benefiting some plants in the area, which in turn is attracting a larger diversity of insects and invertebrates.
Salamanders and snakes may then be following these creatures, creating a more diverse animal population overall in areas with deer.
"Another possibility is that we are observing a 'refuge effect,' where animals in the grazed areas are more likely to use the cover objects than animals in the ungrazed areas. If the ground in the exclosures really is more favorable, as we originally thought, maybe the animals there just have no need for our artificial cover boards," Greenwald said.
But no matter what the reason, she cautions that the take-home message of the study is that officials need to understand the forest ecosystem before making decisions about wildlife management.
"We need to be aware of what's happening in these forest ecosystems. Culling deer may cascade into affecting plants, salamanders, and other creatures in ways we can't even imagine. So before we start removing deer we should study what's really happening in these areas because there are a whole host of other issues that go along with culling," she said.
|Contact: Katherine Greenwald|
Ohio State University