Genetic assessment of the Atlantic Forest bristle porcupine, Chaetomys subspinosus (Rodentia: Erethizontidae), an endemic species threatened with extinction

Combining species distribution modeling and field surveys to reappraise the geographic distribution and conservation status of the threatened thin-spined porcupine (Chaetomys subspinosus)

The threatened thin-spined porcupine (Chaetomys subspinosus), a forest-specialist endemic to the Brazilian Atlantic forest, was rarely detected in the wild during the 20th century. Previous geographic distribution assessments were carried out nearly three decades ago and were based on interview data. We performed extensive field surveys (based on active search and interviews), a literature review, and species distribution modeling to predict and validate a more reliable picture of its geographic distribution and environmental suitability gradient. We identified the main predictors of species' incidence, its conservation status, and pinpointed key areas for species conservation. Our results indicated that C. subspinosus is distributed continuously in the Atlantic forest from southeastern Espirito Santo to central-eastern Sergipe state, totaling 104,326 km2 of occurrence area, although only 3,299 km2 (13.3%) is currently represented by native forests (species habitat). C. subspinosus was absent or at least so rare that it was not detected in more than half of the locations sampled by interviews (53.5%). Our results suggest that populations are sensitive to climatic conditions and habitat loss, becoming abruptly rarer when the remaining forest cover reaches less than 10% area within a region (~ 5,000 km2 scale). This result indicates that the high deforestation level of the Atlantic forest is already close to the limit of regional species resistance. Bahia state still harbors the bulk of the remaining forest with high climatic suitability, and generally under low levels of legal protection. Herein we highlight priority areas and research gaps that could guide decision makers to promote conservation strategies for this threatened species.

Do we underestimate the impact of roads on arboreal animals? Roadkill as an important threat to Chaetomys subspinosus (Mammalia: Rodentia)

Abstract: The Thin-spined Porcupine (Chaetomys subspinosus) is a medium-sized and mainly arboreal rodent, endemic to the Brazilian Atlantic Forest, and threatened with extinction. Habitat loss, hunting, forest fires, agriculture and livestock are threats identified for the species. Here we raise the alert to the impact of roads on remaining populations of C. subspinosus based on roadkill records from the state of Espírito Santo, southeastern Brazil. Mortality due to roadkill is likely to impact C. subspinosus in different regions of the state, and is a widespread problem, not unique to a single location or population. The pattern of roadkills in the studied regions suggest that the species is more susceptible to collisions with vehicles in the breeding period. Additionally, concrete barriers that divide lanes on highways seens to increase the likelihood of roadkill for Thin-spined Porcupines. We recommend that roadkill should be included in the list of threats to C. subspinosus in the Espírito Santo. Mortality due to roadkill is probably relevant also for populations in the states of Bahia and Sergipe, and it should be evaluated locally. The installation of road-crossing structures for wildlife, such as arboreal overpasses, is recommended on roads crossing or close to protected areas with C. subspinosus presence in Espírito Santo and elsewhere.