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.

Road Infrastructure and Primate Conservation: Introducing the Global Primate Roadkill Database

“…The three species within the GPRD with the most reported roadkill incidents were all classified as Least Concern; however, like most primates, they were also threatened by habitat destruction and fragmentation [73][74][75]. For one of these species, the white-headed marmoset, it is important to note that 195 roadkill incidents were reported between 2001 and 2015 in a single region of Brazil [15]. Given the exponential rate of habitat loss and land conversion in Brazil, it is possible that WVCs may pose a serious threat to local populations.…”

“…As a result, wildlife-vehicle collisions (WVCs) involving primates are becoming more frequent [14]. Despite many primates being arboreal, roads present potential obstacles that often force primates to descend to the ground to access fragmented forest patches on the other side [15]. Within both urban and rural areas, primates may frequently cross roads for access to resources and/or for reproductive opportunities, leading to WVCs and potential death [16,17].…”

“…Therefore, the collation of primate roadkill data may indicate the true extent of the threat that WVCs pose to their populations. In fact, primate mortality along roads is likely underestimated due to the absence of systematic roadkill monitoring in most primate range countries [19], although some roadkill studies include primates in their published datasets, e.g., [15,[20][21][22]. Of the few primate-focused roadkill studies, Hetman and colleagues [23] identified several globally threatened primate species involved in fatal WVCs, including a high incidence of infant/juvenile mortality.…”

Factors that drive koala roadkill: an analysis across multiple scales in New South Wales, Australia

“…Wildlife roadkill is a problem on an international scale, and Australian policy writers and road planners can continue to benefit from knowledge from across the globe (Rajvanshi et al 2001;Sherwood et al 2002;Forman et al 2003;Malo et al 2004;McCall et al 2010;Laurance et al 2014;van der Ree et al 2015;Dopp 2017;Srbek-Araujo et al 2018;Collinson et al 2019;Kreling et al 2019). However, there remains the pressing need to manage specifically for koalas, meaning that purely generic approaches directed at any type of roadkill may not be adequate.…”

Arboreal wildlife bridges in the tropical rainforest of Costa Rica’s Osa Peninsula

“…Slicing through ecosystems, linear infrastructures -such as roads -affect the integrity of habitats worldwide (Laurance et al, 2009;Freitas et al, 2010). A barrier to animal movements and a cause of mortality, roads decrease gene flow and increase the probability of local extinctions, especially for arboreal species (Wilson et al, 2007;Yokochi et al, 2015;Asensio et al, 2017;Srbek-Araujo et al, 2018). Arboreal wildlife bridges, however, have proven a successful tool to overcome this conservation challenge.…”