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

Abstract

Climate change represents an unprecedented threat to global biodiversity and, for many species, gaps in our knowledge of their biology remain acute. Gaps in baseline knowledge, such as confirmed identifications (Linnean shortfalls) and adequate collections (Wallacean shortfalls), need to be minimized with new studies, since this is often critical for effective conservation. Despite the increase in scientific research on primates in the southwest of the Brazilian Amazon, little is known about the species Mico nigriceps (Ferrari & Lopes, 1992) Primates, Platirryni. In the current study, we sought to reduce the extent of the Wallacean shortfall for M. nigriceps, understand whether climate change represents a threat to the distribution of the species, and identify priority areas for its conservation. Accordingly, we provide 121 new records in 14 locations, obtained directly from the field, and five from the literature. Using this, we carried out ecological niche modeling, to better understand how environmental suitability might limit the area occupied by the species. We then projected a distribution for 2070 with the SSP2-4.5 (more optimistic) and SSP5-8.5 (more pessimistic) scenarios. Our data confirmed the geographic distribution of the species as being restricted to headwaters of the Ji-Paraná/Machado river, but with a 400 km extension to the south. Under the modeled climate change scenarios, the area suitable for the species declines by 21% under the most optimistic, and by 27% in the pessimistic, scenario across the projected 50-year period. Although we have expanded the area of known occurrence for this species, we point out that climate change threatens the stability of this newly-discovered population strongly, and that this danger is intensified by deforestation, fire and hunting. We recommend that further studies be carried out to confirm the presence of the species in adjacent areas, those indicated by generated models as being potential environmentally suitable. In addition, we recommend intensifying forest restoration in currently pastured areas, and protection of the areas forming the current and future habitat of this species through such measures as protected area creation.

Fig 1. Study area map.

Map of southwestern Brazilian Amazon showing new records of M. nigriceps, and the other known records of species of the genus Mico. The records for M. rondoni were extracted from [24, 25]; M. melanurus records are from [26, 27]; M. intermedius and M. marcai records were extracted from [28]. Reprinted from Souza et al. (10.3390/rs12172735) under a CC BY license, with permission from MapBiomas project, original copyright 2019. MapBiomas Project—Collection 5 of the Annual Series of Coverage and Land Use Maps in Brazil, accessed on 04/14/2021 through the link: https://mapbiomas.org/colecoes-mapbiomas-1?cama_set_language=pt-BR. Shapefiles by: Ministério de Meio Ambiente.

Fig 2. Analyzed skins.

Road-kill derived specimens deposited in the Mastozoologia collection, CELBE Pantanal, and analysed for the current study (Photo: O. Silva-Diogo).

Fig 3. Modeling-generated map.

Modeling-generated map of current and future distributions for M. nigriceps. Mico nigriceps illustration reprinted from Ferrari and Lopes (1992) under a CC BY license, with permission from Stephen D. Nash, original copyright 2021. Shapefiles by: Ministério de Meio Ambiente. AES Area.