Strips of land meant to connect natural habits separated by agriculture (called wildlife corridors) could encourage the spread of invasive species.
These findings are especially relevant in Florida, where invasive species are a consistent problem, the University of Florida reported. Animals such as the cuban tree frog, green iguana, Burmese python, and feral hogs run rampant across the Sunshine State. University researchers demonstrated the phenomenon in imported fire ants.
"Although habitat corridors are usually beneficial, they occasionally have negative effects," study leader Julian Resasco said. "Sometimes they can help invasive species spread in exactly the same way they help native species."
Researchers were surprised by these results because invasive species are incredibly skilled at invading new areas without needing corridors.
Fire ants have two social forms: monogyne and polygyne. Monogyne fire ants have the ability to fly higher than others and mate in the air, polygene ants mate closer to the ground. Polygene ants do not disperse their populations as widely as monogyne ones do.
To make their findings the researchers looked at regions of South California dominated by each of the social forms. The sample consisted of five patches of land, each about the size of a football field. Some of these regions were connected by corridors while others were not.
The team found the corridors significantly reduced the abundance of polygene, but not monogyne fire ants.
"It is not a coincidence that the readily dispersing monogyne form of fire ants doesn't benefit from corridors, whereas the poorly dispersing polygyne form does," Resasco said.
More analysis will be required in order to determine the true effects of corridors on invasive species. The recent paper, published in the August issue of Ecology, urges land managers to consider the local animals' traits before making final decisions on whether or not to implement land corridors.
