PRESCRIBED FIRE AFFECTS DIURNAL VERTEBRATE USE OF GOPHER TORTOISE (GOPHERUS POLYPHEMUS) BURROWS IN A LONGLEAF PINE (PINUS PALUSTRIS) FOREST

摘要

Frequent fires arc essential for maintaining the Longleaf Pine (Pima palustris) ecosystem and arc beneficial to the Gopher Tortoise (Gopherus polyphemus), a Longleaf Pine specialist that excavates burrows used by many commensal species. Presumably, burrows offer important refugia to commensals both during and after fires, but no published studies have confirmed this. Therefore, the objective of this study was to examine how prescribed fire influences diurnal vertebrate use of Gopher Tortoise burrows. We deployed trail cameras in 46 burrows before a prescribed lire and monitored vertebrate activity until we removed cameras 11 d after the fire. We compared vertebrate burrow use before and during the prescribed fire and also used data from a previous study to compare vertebrate use of burrows on an unburned site to that of our recently burned site. We observed one vertebrate commensal at 43 monitored burrows (0.02 vertebrates per camera) on the day before the burn and nine vertebrates at 41 burrows (eight species, 0.22 vertebrates per camera) during the burn. In addition, we observed 8.5 times more vertebrates using burrows at the recently burned site than at an unburned site (51 individuals of seven species versus six individuals of three species, respectively). Our results suggest that Gopher Tortoise burrows offer important diurnal refugia to commensals from direct (risk of mortality) and indirect (perceived risk of predation and/or injury) effects of fire. Additional studies would be beneficial on nocturnal vertebrate burrow use, longer-term trends as vegetative cover regenerates following fire, and relative importance of other refugia for vertebrates.