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

Our results also indicate that climate change will have a negative impact on the area of occurrence of this species, both that historically-known and the area newly-added by the cur- rent study, especially in the most pessimistic scenario, SSP5-8.5. Under both optimistic and pessimistic climate change scenarios, AES losses in the previously-known area of occurrence [11] will be 100%. Additionally, it will also be very severe in both the new area of distribution described in this study, and in the areas adjacent areas indicated by ENM as likely to harbor the species. Even under the most optimistic scenario, losses to the M. nigriceps AES will be sig- nificant. This reinforces the opinion that biodiversity in the southern Amazon region will be strongly impacted by changes in climate [43], with the current study acting as a bellwether for this. Modeling points to other work that the climate change in the neotropical region has been affecting the distribution of low mobility mammal species since the last glacial maximum [44]. In the future, this trend could to aggravate associated with deforestation that can take approxi- mately 25% of mammalian species to lose> 40% of their current habitat [45]. This is especially worrying for neotropical primates that lives in trees. Thus, due the changes in environmental conditions, enhanced by the intensification of highly-impactful human activities [46] the sta- bility of primates populations is also at risk, as already discussed for Ateles chamek, Lagothrix

cana and Leontopithecus chrysopygys [47–50], mainly in the Amazon / Cerrado Ecotone Region. The probability of a decrease in the occurrence of these species is intensified under future climate change scenarios, since the habitat fragmentation associated with changes in cli- mate conditions strongly threatens population stability, as well as with interaction networks with other populations [46]. Therefore, climate change threatens the existence of species like M. nigriceps, whose histori- cal shortfalls in identification and sampling have been remedied only recently. The results of the current study highlight the need to intensify field studies so that conservation actions can be prepared for other species in similar situations. For these, ENM can assist in identifying both study areas, and priority sites for the effective conservation of such species [50]. For M. nigriceps, the loss of an AES within its current range represents a threat to the existence of the local population, which can be a prelude to the extinction of the species as a whole [51]. As a member of an iconic taxon, the primates, measures to conserve M. nicriceps species would act as an umbrella for the protection of many others in the region. Accordingly, we sug- gest efforts are concentrated in areas with the greatest suitability for such species, especially those which contain native vegetation, but which do not yet have legal status as protected area. Private areas with native forests are also important for species conservation. For this, investing

in land use planning must be a priority, since they can establish such areas as Legal Reserve and Environmental Preservation Areas, as governed by Brazilian legislation. This should be both studied and have protection extended to them. We emphasize the necessity of intensify- ing conservation efforts linked to this species, since the area that modeling indicates as environmentally appropriate for it is located in the Brazilian Amazon “arc of deforestation”. The biodiversity of this region has been severely impacted by human actions resulting from the expansion of export-related agricultural activities, in addition to deforestation, which has increased exponentially in recent years [52] and recent fires, mainly in the years 2019 and 2020 [52]. These actions have been intensified by the weakening of environmental protection poli- cies in Brazil, especially in the Amazon [53]. This increases the need to carry out reforestation activities in these areas, as well as in areas used as pastures. While this should occur in priority areas, we would also suggest this action be implemented in adjacent areas, with lower possibil- ity of predicted future occurrence. We suggest this since it both provides protection to the pri- ority areas, via buffering, and strengthens the connectivity matrix between the forest fragments, enabling long-term population viability. PLOS ONE Modeling of Mico nigriceps PLOS ONE | https://doi.org/10.1371/journal.pone.0256270 September 7, 2021 10 / 14