Herpetological Conservation and Biology最新文献

Turtle populations are in decline worldwide, requiring immediate conservation and management actions. For species with broad geographic ranges that cover diverse environmental contexts, region-specific information on declining species could inform more targeted management plans. I examined the ecology of a Spotted Turtle (Clemmys guttata) population in a temporally dynamic wetland system in the Southeastern Plains ecoregion of North Carolina. Turtles selected forested wetlands and streams while avoiding open wetlands and river habitats, but used terrestrial habitats minimally and randomly. Turtles responded to wetland drying by remaining in wetlands and maintaining modest levels of activity during short-duration drying events (< 1 mo), but moved very little during longer droughts (7 mo). Turtles had prolonged active seasons (February-October) as long as wetlands and streams were flooded, with movement rates peaking in late spring at 23.6 ± 3.7 m/d (mean ± standard error). Turtles had large home ranges (14.1 ± 4.3 ha) that often included multiple local stream networks used as movement corridors between forested wetland patches and as activity centers when wetlands dried. I suggest that conservation plans for C. guttata include large management areas that protect a network of streams and adjacent forested swamps in the Southeastern Plains and perhaps other lowland ecoregions in the Southeastern U.S. Because terrestrial habitats were not used for extended refuge during drought, certain low-impact land uses in adjacent terrestrial areas are not likely to negatively impact C. guttata populations, but terrestrial forests would still be important in maintaining overland travel corridors.

The Mountain Coqui (Eleutherodactylus portoricensis) is a frog endemic to montane rainforests in the Cordillera Central and Luquillo Mountains of Puerto Rico. Classified as endangered by the IUCN Red List and as vulnerable by the Department of Natural and Environmental Resources of Puerto Rico, this species has undergone considerable decline in the Luquillo Mountains. To evaluate the population status of E. portoricensis across its entire range, we conducted ~87 hours of surveys at 18 historical localities and 25 additional localities that we considered suitable for this species. We generated occupancy models to estimate the probability of occurrence at surveyed sites and to identify geographic and climatic factors affecting site occupancy. We also constructed a suitability map to visualize population status in relation to the presence of land cover at elevations where the species has been documented, and determined the dates when populations were last detected at historical localities. Eleutherodactylus portoricensis was detected at 14 of 43 localities, including 10 of 18 historical localities, but it was not detected at any localities west of Aibonito (western Cordillera Central). Occupancy models estimated the probability of occurrence for localities in the western Cordillera Central as zero. Site occupancy was positively associated with montane cloud forest, and negatively associated with the western Cordillera Central, maximum temperature, and precipitation seasonality. The suitability map suggests that declines have occurred despite the presence of suitable habitat. We suggest upgrading the extinction risk of E. portoricensis and potentially developing a captive breeding program for this species.