Challenges and Unique Solutions to Rodent Eradication in Florida

Abstract

Once established, invasive rodents cause significant impacts to island flora and fauna, including species extinctions. There have been numerous efforts to eradicate invasive rodents from islands worldwide, with many successes. For a number of reasons, many invasive vertebrates have become established in Florida, including several rodent species. We have implemented rodent eradication efforts on two Florida islands. Using the successful eradication strategy developed for Buck Island, U.S. Virgin Islands, we have attempted the eradication of roof rats from Egmont Key off Tampa Bay. We also are attempting to eradicate Gambian giant pouched rats from Grassy Key in the Florida Keys. On Egmont Key, we used a grid of bait stations containing diphacinone rodenticide bait blocks and hand tossing of bait blocks into thickets. On Grassy Key, we used a grid of bait stations containing a zinc phosphide bait along with intensive live-trapping. We discuss the eradication planning, efforts to minimize nontarget animal losses, and follow-up activities. We also discuss some of the difficulties encountered in each of these two different situations.