Range, Wildlife and Fisheries Management
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Joe Treadway, Jr., C. Brad Dabbert, and Robert B. Mitchell
The red imported fire ant (RIFA) has
become a major agricultural and wildlife pest since its introduction to the United States
in the 1930s. Recent research at Texas Tech
University has shown that northern bobwhite chick survival and nest success decline
sharply as RIFA densities increase. With the
addition of this additive source of mortality, other factors may have an increased impact. We are attempting to determine if bobwhite hens
whose nests are protected from mammalian predators will have more chicks survive until
fall than hens whose nests are exposed to predation.
Our target species of predators include: raccoons,
opossums, and striped skunks.
We built 4 ft by 4 ft by 18 inch wire exclosures from 2 by 4 inch fence wire and staked them to the ground to exclude raccoons, opossums, and striped skunks. This wire allowed the birds to come and go unhindered while limiting access by other species. Hens were trapped early in the year, fitted with a radio transmitter, and followed to locate their nests. When the nest was found, one of three treatments was randomly applied. The first was a control, the second was a RIFA insecticide, and the third was the insecticide plus an exclosure. The exclosure was centered on the nest and the insecticide was applied in a 180 by 180 ft grid centered on the nest. The chemically treated area approximated the foraging distances of the ants. We also applied a snake repellent around the exclosures.
Exclosures were used to prevent predation of northen bobwhite nests.
Preliminary analysis based on our
first year of data collection suggests nests protected by exclosures have higher success
rates than untreated nests. Only one
exclosure nest was destroyed. Plans are to
replicate the study through a second nesting season.