New records and modelling the impacts of climate change on the black-tailed marmosets

The results also indicate the presence of M. nigriceps in protected areas (PAs) and indige- nous land (IL) (S2 Table in S1 File) under the current climate regimen, both for the geographic range as originally described (282.83 km2), as well as for the newly-expanded distributional area reported by the current study (252,978.69 km2). In total, under the current climatic regime 7.25% of the expected area of occurrence of the species overlaps with protected areas. However, most of the distribution of the species area (~82.8%) overlaps with areas under pas- ture and on private properties. In the future, this scenario worsens, as AES for M. nigriceps in PAs and ILs is predicted to occur only in the area of occurrence added by the current study, declining to 4,552.96 km2 in the SSP2-4.5 scenario and 32.39 km2 in the SSP5-8.5 scenario. Both climate change scenarios indicate that there will be AES for this species only in IL Sete de Setembro (Table 1). Discussion The results obtained during this study considerably expanded the number of known M. nigri- ceps records, which enabled to know better the distribution of the species and to model its AES. When the geographic distribution limits of M. nigriceps were defined by [11], it included the area east of the Ji-Parana´/Machado and Madeira rivers, and west of the Marmelos river. The southern limit was described as a plateau of non-forested land that separates the head of the Marmelos river from the right bank of the Ji-Parana´ river. Consequently, the new occur-

rence records have provided evidence of a range extension of the distribution of more than 400 km south. This more than doubles the extent of the scientifically-established distribution of the species, and can be considered as a good approximation of the area of M. nigriceps´s dis- tribution. The confirmation of the presence of species to the south of its formerly known range is of great importance, precisely because it is an area where a large area of native forest (and hence suitable habitat) still remains. The models shows that the known area of distribution of the species [11] occupies only a small part of the potential AES indicated by the ENM [11]. The ENM indicated adjacent areas with AES potential for the species, which highlights the need for studies in these new areas to confirm these predictions [9]. Results also suggest that the type locality may occupy a periph- eral portion of the actual geographic range of the species. This reinforces the important contri- bution that ENM can make to rare species conservation studies, since the models generated under the present climate scenario indicate an area of environmental suitability for the species in the areas where our field surveys confirmed actual presence. Thus, this tool can be useful for guiding future studies on other species whose true distribution is little known. Table 1. Protected areas (PAs) and indigenous lands (ILs) with AES for M. nigriceps in current climate scenario, and under the scenarios SSP2-4.5 and SSP5-8.5 (expressed as km2). Histo´rical occurence area Current climate SSP-4.5 SSP-8.5

PA Nova Aurora 18.52 - - PA Gibeão 31.29 - - PA Irmão Satelis 41.09 - - PA Jaru 125.76 - - IL Roosevelt 141.65 141.65 - IL Igarape´ Lourdes 1,816.87 605.88 - IL Zoro´ 2,656.59 1,575.40 - IL Sete de Setembro 248,146.92 2,230.04 32.39 Total 152,978.69 4,552.96 32.39 https://doi.org/10.1371/journal.pone.0256270.t001 PLOS ONE Modeling of Mico nigriceps PLOS ONE | https://doi.org/10.1371/journal.pone.0256270 September 7, 2021 9 / 14