Using population surveys and models to reassess the conservation status of an endemic Amazonian titi monkey in a deforestation hotspot

Assessing the conservation status of species is essential for implementing appropriate conservation measures. A lack of evidence of threats, rather than showing an absence of impacts, could reflect a lack of studies on how human activities could result in species population declines. The range of Prince Bernhard's titi monkey Plecturocebus bernhardi is restricted to the Arc of Deforestation, a deforestation hotspot in south-eastern Amazonia. Despite this, it is categorized as Least Concern on the IUCN Red List. To reassess the conservation status of P. bernhardi, we carried out surveys during 2015–2017 to delimit the geographical distribution of the species and estimate its population density and abundance. We then used spatial predictive modelling to examine future habitat and population loss within its range. Plecturocebus bernhardi occurs over an area of 131,295 km2. Its mean group size was 2.8 individuals/group and its density 10.8 individuals/km2 and 3.8 groups/km2. Habitat loss was estimated to be 58,365 km2 (44.5% of its current range) over the next 24 years (three P. bernhardi generations) under a conservative governance model of deforestation and 105,289 km2 (80.2%) under a business-as-usual model. These numbers indicate that P. bernhardi is threatened and should be categorized as Vulnerable, at least, using the IUCN Red List criteria. We recommend the reassessment of other Least Concern primate species from the Arc of Deforestation using a similar approach

Geographic range extension of Elachistocleis corumbaensis Piva, Caramaschi & Albuquerque, 2017 (Anura, Microhylidae) with new records in ecotonal zones in the state of Mato Grosso, Brazil

Elachistocleis corumbaensis was documented in 2017 in the central region of the Brazilian Pantanal and no other record of the species has since been reported. In this study, we report on the extension of the geographic range of E. corumbaensis based on 4 new records found in the riparian forests of the Paraguay River, in the state of Mato Grosso. Of these, 1 specimen was collected in a protected area in the Pantanal. We also report on the presence of this species in the ecotones between the Pantanal, Cerrado, and Amazonia, which suggests that E. corumbaensis is associated with seasonally flooded forests but more widely distributed in western Brazil than previously reported

New records and distribution map of Gold-striped Frog, Lithodytes lineatus (Schneider, 1799) (Anura, Leptodactylidae), in an ecotonal zone in Mato Grosso, Brazil

Lithodytes lineatus (Schneider, 1799) is a small, litter-dwelling frog widely distributed in the Amazon Ecoregion and some transitional areas between the Amazon and Cerrado. Here we report seven new records of this species in a transitional zone between Amazon, Chiquitano Dry Forest and Cerrado ecoregions in the state of Mato Grosso, Brazil. These are the southernmost records of the species, expanding its distribution in 320 km from the nearest record in Bolivia

An extension of the known geographic distribution of Sapajus cay (Illiger, 1815) (Primates, Cebidae) in southwestern Brazilian Amazonia

We update the geographic distribution of Sapajus cay in the south-central, southeast, and western portions of Mato Grosso state, Brazil, and extend the distribution of this species north to the Cabixi River at the border with the state of Rondônia. Data were obtained from field surveys. We observed individuals of S. cay in highly fragmented forests which have been impacted by the deforestation over the past 50 years. This is an alarming situation for the conservation of the region’s fauna

New records of Apostolepis kikoi Santos et al., 2018 (Serpentes, Dipsadidae) in the state of Mato Grosso, Central-West Brazil

The fossorial snake Apostolepis kikoi Santos et al., 2018 is known only from its type locality, in Chapada dos Guimarães, state of Mato Grosso, Brazil. Here, we present the first records of this species after its description, expanding its distribution to transition areas between the Amazon and Cerrado biomes, in the southwestern portion of Mato Grosso. The new record expands the known distribution of A. kikoi by 297 km west from the type locality. In addition, we provide data on morphological variation by comparing our sample with the type series

Niche overlap between two sympatric frugivorous Neotropical primates: improving ecological niche models using closely-related taxa

Ecological niche models (ENMs) are widely used tools for predicting species geographic distribution as a function of environmental variables. The inclusion of biotic factors in the predictor suite can significantly increase the predictive power of such models, leading to a model closer to the realized niche for the species under investigation. In this study, we provide evidence of niche overlap between gray woolly monkeys (Lagothrix cana) and black-faced black spider monkeys (Ateles chamek) based on locality and ecological data covering their complete geographic range in the Amazon forests of Brazil, Peru and Bolivia. We also estimate the potential distribution of L. cana using environmental predictors, and the distribution of A. chamek as a biotic factor. Finally, we quantified current and future habitat loss and areas under legal protection. We found that only 39% of the L. cana area of occupancy is under legal protection and that the species could potentially lose up to 58% of habitat in the next 30 years. We also show that the use of a closely-related species that has a more robust dataset can improve ENMs of poorly studied, rare and/or cryptic species. The framework developed here can be applied to a wide range of sympatric species if they share similar ecological requirements. Since our focal species are the most frugivorous primates in our study region and especially vulnerable to habitat loss, the identification of highly suitable areas for both taxa can help to protect other forest-dwelling species, reducing the rate of overall biodiversity loss. © 2020, Springer Nature B.V

New records amplify the geographical distribution of Rondonops biscutatus Colli et al., 2015 (Squamata, Sauria, Gymnophthalmidae) into the Paraguay river basin, Mato Grosso, Brazil

Rondonops biscutatus is a gymnophthalmid litter-lizard which occurs in the Amazon rainforests and the transitional areas between Amazonia and Cerrado. This species’ distribution is strongly biased by a lack of data, possibly because it was recently described, small-bodied, and living in cryptic habits. Here, we present occurrence data of six specimens from four locations in transitional areas between forests in Amazonia and Cerrado (central Brazil), in the upper Paraguay River, at the northern end of the Pantanal, midwestern Brazil. We expand the distribution of this species 507 km east from its original range.