Abstract or Keywords
As uplands across the southeastern US confront a burgeoning human population, native ecological communities are increasingly stressed by increased predators via urban subsidies to native and invasive predators. Due to a long-standing successful habitat conservation and management program, a natural population of gopher tortoises (Gopherus polyphemus) remains in an urban nature preserve in St. Petersburg, Florida. An ongoing long-term study of tortoises at the site has identified more than 200 unique individual tortoises in this population. Between summer 2023 and 2024, however, more than 20% of the adult tortoise population was found to have been killed by coyotes, which are an invasive species in Florida. The depredated shells of many previously marked, healthy, and reproductive adult tortoises were found across the site and frequently cached and surrounded by coyote scat. Many of these shells were broken throughout individual bones (consistent with a large-gaping canine predator), not just along bone sutures. Three caches of tortoise shells also included other similar-sized carcasses of two other species (domestic cat, Felis catus, and nine-banded armadillo, Dasypus novemcinctus). An unquantifiable number of juvenile and hatchling gopher tortoises have also recently been killed by coyotes at the site, as evidenced by coyote scat in an adult tortoise shell cache containing hatchling tortoise shell scutes. Given the high number of previously-marked and well-studied but recently-depredated tortoises that have been recovered, this presentation will focus on the demographic features of the depredated population (including, sex, size, social network status, and reproductive output of the dead animals). Lastly, we will put this into a broader context and discuss the viability of >20% annual adult mortality and how this should impact regional management of invasive coyotes and this rapidly-declining ecological community.