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

the incumbent Brazilian government have resulted in a loosening of environmental law enforcement, and enhanced natural habitat degradation [18]. In this context, Ecological Niche Modeling (ENM) can be used to guide sampling efforts. The ENM produces layers of range of species distribution, using the environmental variables of locations with known occurrence records, that is, allows determination to a species her envi- ronmental suitability area (ESA). This can, by extrapolation, be used to identify new sites where occurrence is likely, thus helping to minimize the effects of any Wallacean Shortfall [19]. In addition, ENM makes it possible to project into the future the distribution of species suitability under different climate change scenarios. This allows assessment of the extent and nature of the effects of climate change on the distribution of the target species, making it highly relevant for guiding biodiversity conservation policies, such as measures aimed at creating and maintaining conservation units [20, 21]. As a result, ENM is a useful scientific tool for improv- ing knowledge of little-known species, such as M. nigriceps, as well as enabling quantified esti- mates of the degree of threat that such species will face under various climate change regimes. In the current study we have used a new set of field-derived records and ENM to achieve the following objectives: 1) expand the known distribution area of the species Mico nigriceps; 2) Identify locations with highest potential environmental suitability for this species; and 3) to

understand whether climate change will affect the extent and distribution of areas environ- mentally suitable for this species, considering the predictions for the year 2070. Materials and methods Study area We collected M. nigriceps location records via direct field sampling efforts in an area located between the middle Ji-Parana´/Machado and Comemorac¸ão rivers (Fig 1). Sampling occurred between June 2008 and January 2020. The regional phytophysiognomy is of Open Rainforest [22], containing terra firme (never-flooded) and floodplain (igapo´) forest forms throughout. The climate is of the tropical AW type (warm and humid), with a dry season during the coldest months (June to September), and a rainy season during the warmer months (December to March), with an average temperature of 26˚C [23]. Occurrence records The new M. nigriceps records were obtained during five expeditions: a rapid inventory of pri- mates at Fazenda Cajazeiras, carried out between June 20, 2008 to June 29, 2008, “Line 2”, Cacoal, Rondoˆnia, Brazil, totaling 72 hours of sampling effort; rapid mastofaunal inventory of Sı´tio Laranjeiras, carried out on February 12 and 13, 2009, “Line 10”, Cacoal, Rondoˆnia, total- ing 16 hours of sampling effort; a survey in the Jaru Biological Reserve, from October 28 to 30, 2016, in the city of Ji-Parana´, Rondoˆnia, totaling 26 h of sampling effort. Other records occurred opportunistically during travel within the region. To identify the species, we photographed the animals encountered during field studies, and

collected four specimens found as road-kill. These specimens were taxidermized and deposited in the Mastozoologica Collection of the Limnology, Biodiversity and Ethnobiology Research Center of the Pantanal, Mato Grosso State University, Ca´ceres, Mato Grosso, Brazil, (CELBE-- M-ODS-002; CELBE-M-ODS -003; CELBE-M-ODS-010 and CELBE-M-ACG-1399). They were used for comparison with the illustrations and diagnosis of M. nigriceps described in Fer- rari & Lopes (1992) [11], and images of skins available in Garbino (2014) [28]. We also com- pared them with skins of the species deposited at the Museu Paraense Emı´lio Goeldi (MPEG 22960; MPEG 22962). Comparison of museum collection specimens, and the photographs of the encountered animals, confirmed the species identification. We used the occurrence PLOS ONE Modeling of Mico nigriceps PLOS ONE | https://doi.org/10.1371/journal.pone.0256270 September 7, 2021 3 / 14