Human-modified landscape acts as refuge for mammals in Atlantic Forest

Abstract

Human-modified landscapes (HMLs) are composed by small, isolated and defaunated forest fragments, which are surrounded by agricultural and urban areas. Information on species that thrives in these HMLs is essential to direct conservation strategies in local and regional scales. Since HMLs are dominant in the Atlantic Forest, we aimed to assess the mammalian diversity in a HML in southeastern Brazil and to propose conservation strategies. We collected data of terrestrial (small-, medium- and large-sized) and volant mammals in three small forest fragments (10, 14 and 26 ha) and adjacent areas, between 2003 and 2016, using complementary methods: active search, camera trapping, live-traps, mist nets and occasional records (i.e., roadkills). In addition, we used secondary data to complement our species list. We recorded 35 native mammal species (6 small-sized, 16 medium- and large-sized, and 13 bats) and seven exotic species in the HML. The recorded mammal assemblage (non-volant and volant), although mainly composed of common and generalist species, includes three medium- and large-sized species nationally threatened (Leopardus guttulus, Puma concolor and Puma yagouaroundi) and two data deficient species (Galictis cuja and Histiotus velatus), highlighting the importance of this HML for the maintenance and conservation of mammal populations. Despite highly impacted by anthropogenic disturbances, the study area harbors a significant richness of medium- and large-sized mammals, being an important biodiversity refuge in the region. However, this biodiversity is threatened by the low quality of the habitats, roadkills and abundant populations of domestic cats and dogs. Therefore, we stress the need of conservation strategies focusing on the medium- and large-sized mammals as an umbrella group, which could benefit all biodiversity in the landscape. We recommend actions that promotes biological restoration, aiming to increase structural composition and connectivity of the forest fragments, reducing roadkills and controlling the domestic cats and dogs' populations, in order to maintain and improve the diversity of mammals in long-term.

Short and Narrow Roads Cause Substantial Impacts on Wildlife

“…The roadkilled native species represented ~56% of all medium-and large-sized mammals that are known to occur in the study area (N = 16; Bovo et al 2018). The most frequently roadkilled species -D. novemcinctus, N. nasua, H. hydrochaeris, D. albiventris and C. spinosus -are commonly recorded in HMLs (Dotta & Verdade 2011, Reale et al 2014Magioli et al 2016), and in other road ecology studies (Coelho et al 2008, Cáceres et al 2010, Dornas et al 2012, Huijser et al 2013.…”

“…We focused on the first 4.35 km of the CPM road, because this area still sustains substantial wildlife populations, especially bird species (N = 205; Alexandrino et al 2013) and mammal species (N = 35; Bovo et al 2018). A high biodiversity is still present, despite the intense human impacts on the landscape (i.e., urban, industrial, and agricultural areas).…”

“…In addition, there is a substantial amount of vegetation growing in the road shoulders, particularly grasses, which is an attractive food source to this species. Other large mammals such as Mazama gouazoubira (Artiodactyla, Cervidae) and P. concolor, are also known to occur in the adjacent forest remnants (Bovo et al 2018), and wildlife-vehicle collisions with these species may also result in human injuries and fatalities (Huijser et al 2013). One individual of Mazama spp.…”

“…Although not recorded as roadkill, three threatened mammal species are known to occur in the study area: Leopardus guttulus (Carnivora, Felidae), P. concolor and Puma yagouaroundi (Carnivora, Felidae) (Bovo et al 2018). These felids face a similar situation as G. cuja and L. longicaudis; the loss of a single individual can not only have a severe impact on their local population, but they can also affect ecosystem dynamics and trophic structure at a local scale (Rheingantz & Trinca 2015), since they are among the few remaining predators.…”

“…These roads can bisect these natural areas and streams, while linking cities to housing developments, isolated houses and farms, and other villages and cities. These HMLs may still host high biodiversity (Anjos 2001, Giraudo et al 2008, Dotta & Verdade 2011, Alexandrino et al 2013, Magioli et al 2014a, Magioli et al 2016, Bovo et al 2018. One common characteristic of these landscapes, is that they are highly fragmented, especially in the Atlantic Forest and Cerrado biomes (Klink & Machado 2005, Ribeiro et al 2009), which are the biomes present in the state of São Paulo.…”