Hunting is an ancient human behavior, which likely became complex and efficient gradually through time. We present data from a bibliographic survey (qualitative) and field sampling (quantitative) of primate hunting in Northeastern Brazil. We evaluated hunting threats faced by 14 primate species native to the States of Bahia and Sergipe (three Critically Endangered, three Endangered, three Vulnerable, two Near Threatened, and three Least Concern). Qualitatively, since 2005, we identified 21 academic studies that contained 47 mentions of all six studied genera known to occur in the study area (Alouatta=4, Brachyteles=2, Callicebus=16, Callithrix=8, Leontopithecus=3, Sapajus=14). Approximately half of the citations were for hunting (55.3%; 88.4% of this for bushmeat) and the other half for trapping (44.7%; 90.4% for pet). Quantitatively, we obtained 834 local experts’ citations of primate hunting and capturing at 348 sites. All experts cited Callithrix, 818 cited Sapajus, and 738 cited Callicebus. We argued 539 about hunting for bushmeat (164 positive; 30.4%) and 636 about trapping for pet (189 positive; 30.9%). Callicebus presented 95 citations as bushmeat (30.1% of 326 queries) and Sapajus presented 80 citations as pet (35.7% of 224). Four informants reported hunting Sapajus for pest control because of crop damage. There was a significant difference (Chi²=33.982; df=2; p<0.0001) comparing hunting for bushmeat and pets, with Callicebus (higher bushmeat) and Sapajus (higher pet) presenting significant differences (both p<0.01). The impact of hunting is associated with biological contexts, besides socioeconomic and political, requiring complex-specific attention and efforts in conservation and management strategies, perhaps innovative, even non-prohibitive.

In 2019, a canopy bridge was built connecting two fragments of the Atlantic Forest separated by the Pacatuba unpaved road within the Pacatuba-Gargau Corridor. This bridge was built as part of the Brazilian National Action Plan for the Conservation of Northeastern Primates (Plano de Acao Nacional para Conservacao dos Primatas do Nordeste - PAN PRINE). The forest fragments contain a variety of mammal species, including the endangered primate species Alouatta belzebul and Sapajus flavius. Between September 2019 and March 2020, we monitored the canopy bridge continuously with a Bushnell camera trap; for a total of 204 days of sampling, resulting in evidence of 113 independent passage events. During the monitoring period, four mammal species used the canopy bridge, the Endangered Sapajus flavius (blond capuchin monkey), Callithrix jacchus (common marmoset), Marmosa demerarae (woolly mouse opossum), and Marmosa murina (murine mouse opossum). The common marmoset (Callithrix jacchus) used the bridge most frequently, representing 50.44% of the passage events (57), while the blond capuchin monkey (S. flavius) crossed the bridge in 30 events (26.5% of total crossings). All other mammals used the bridge less frequently than the primates (23% of crossings were of opossums). There was no record of crossings by the red-handed howler monkey (Alouatta belzebul) during the monitoring period. The construction of the canopy bridge within the PacatubaGargau forest corridor promoted structural and functional connectivity of the forest habitats, affecting the movement of the Endangered blond capuchin monkey and the common marmoset and benefiting other arboreal mammal species. The results indicate that monitoring the use of this canopy bridge provided important insights into the behaviour and ecology of the species studied (e.g., activity patterns, social interactions, group sizes, and reproduction, among many others). In addition, the use of the bridge decreases the risks of animal-vehicle collisions and electrocutions. Considering our results, we strongly recommend constructing and implementing canopy bridges as a strategy for the conservation of arboreal species living in fragmented forest areas.

Terrestrial mammals face a severe crisis of habitat loss worldwide. Therefore, assessing information on habitat loss throughout different time periods is crucial for assessing species' conservation statuses based on the IUCN Red List system. To support the national extinction risk assessment in Brazil (2016-2022), we developed a script that uses the MapBiomas Project 6.0 data source of land cover and land use (annual maps at 30 m scale) within the Google Earth Engine (GEE) platform to calculate habitat loss. We defined suitable habitats from the MapBiomas Project land cover classification for 190 mammalian taxa, according to each species range map and ecological characteristics. We considered a period of three generation lengths to assess habitat loss in accordance with the Red List assessment criteria. We used the script to estimate changes in available habitat throughout the analyzed period within the species' known ranges. The results indicated that habitat loss occurred within 94.3% of the analyzed taxa range, with the Carnivora order suffering the greatest habitat loss, followed by the Cingulata order. These analyses may be decisive for applying criteria, defining categories during the assessment of at least 17 species (9%), enriching discussions, and raising new questions for several other species. We considered the outcome of estimating habitat loss for various taxa when applying criterion A, which refers to population reduction, thus supporting more accurate inferences about past population declines.

Despite their importance to conservation strategies, baseline data on species distribution and abundance are lacking for many primates. Discovered 30 years ago, the blond titi ( Callicebus barbarabrownae ) is considered Critically Endangered. The first assessments in 2004-2006 sampled 126, 1-km radius areas using interviews, sightings, and playing back loud calls to confirm the presence of this species in 37 areas, suggesting a minimum population of 260 individuals in the Caatinga biome, Brazil. Ten years later, from 2015 to 2017, we reassessed the species’ distribution range using playback points to survey 224, 1-km radius areas, including 34 occurrence areas from 2004-2006. We counted the number of responding or sighted groups and individuals in each area. We also measured land cover change from 2005 to 2016 in the species’ geographic range. We recorded blond titis in 92 areas, including 28 of the 34 areas occupied in 2004-2006, and three protected areas. We found 194 groups and at least 404 individuals. From 2005 to 2016, forest cover decreased by 11% and urban area increased by 67%. The higher number of occupied areas and individuals we found in 2015-2017 are likely due to the higher sampling effort employed and higher detectability of playback surveys compared to interviews. Although the blond titi occurs in more areas and in higher numbers than previously known, threats related to land use are increasing. We suggest the use of improved observational (e.g., playback) and analytical methods to enhance knowledge of primate distribution and population size.

Ongoing environmental changes may reduce the population size and geographic distribution of many ecologically sensitive species. Predicting where populations will (or will not) be likely to resist these changes is crucial for planning their protection. The blond titi monkey (Callicebus barbarabrownae) is listed as Critically Endangered by the International Union for Conservation of Nature because of its small and declining population due to deforestation and hunting. The species is endemic to the Brazilian Caatinga dry forest, which has undergone extensive deforestation and climate-induced desertification. We address the extinction risk of this species in a spatially explicit context by predicting the geographic distribution of suitable areas that may permit the persistence of potentially viable populations over the next 50 years. We combined species distribution modeling with population viability analysis under more optimistic and pessimistic climate change scenarios and simulated forest loss, assessing how different populations will likely cope with these changes during the coming decades. Future models did not differ between the scenarios, but changes in the climatic suitability of the species’ habitat predicted a reduction of one-third of the currently suitable area. Viable populations in large forest remnants represent only a quarter of all known populations, and they also face a decline in climatic suitability. Smaller populations may be extirpated, regardless of the level of forest recovery. This species’ long-term persistence entails improving habitat quality and the connectivity of the large remnants to neighbor areas. Finally, the integration of spatial and temporal models is feasible and helpful to address threats and aid the conservation of primates.

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data.

Effective management of threatened species requires accurate population size estimation and monitoring. However, reliable population size estimates are lacking for many endangered species. The critically endangered blond titi monkey (Callicebus barbarabrownae) is an endemic primate of the Caatinga biome in Northeastern Brazil. A previous assessment based on presence-only data estimated a minimum population size of 260 mature individuals in 2,636 km2 , and studies based on visual records suggested very low local relative abundance. However, this cryptic species is known to be difficult to visually detect. We played back recordings of C. barbarabrownae loud calls to count the number of responding groups in 34 sampling sites during 9 consecutive days in a 221-km2 study area. Repeated group counts at sites were used in N-mixture models, which account for imperfect detection, to estimate the number of groups in relation to dry forest area and distance to villages. We estimated a total of 91 groups in the study area. Considering the mean number of adults per group as three, we estimated a population of 273 adult individuals, resulting in a density of 2.3 individuals/km2 in the dry forest habitat. Detection probability was four times higher for surveys conducted between sunrise to midmorning than between midmorning to sunset. We also found that C. barbarabrownae abundance increases with increasing dry forest area and increasing distance to the nearest village, indicating the need to promote dry forest restoration in the Caatinga. As our results suggest a larger population of C. barbarabrownae than had been previously estimated for its entire distribution, our results suggest a need for similar assessments in other areas to reliably estimate the total population size. This study demonstrates how playback surveys coupled with N-mixture models can be used to estimate population sizes of acoustically-responsive primates, and thus contribute to more effective conservation management.

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peerreviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other largescale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data.

The effects of habitat fragmentation and deforestation are exacerbated by some elements, such as roads and power lines, which may become filters or barriers to wildlife movements. In order to mitigate mortality and restore connectivity, wildlife passages are being constructed as linear corridors. The installation of these mitigation measures must be followed by systematic monitoring, in order to evaluate their use and effectiveness, to assist in their management, and to convince stakeholders of their value. In this paper we present the results of a monitoring study of the use of rope overpasses developed near a protected area in Porto Alegre, southern Brazil. The canopy bridges were installed by the Urban Monkeys Program in places where electric hazards and road-kills of brown howler monkeys (Alouatta guariba clamitans Cabrera, 1940) were recorded. Camera traps were installed at each bridge, and local people were selected and trained to monitor overpass use over 15 months, from August 2008 to October 2009. Three species were recorded using canopy bridges: brown howler monkey (Alouatta guariba clamitans Cabrera, 1940), white-eared opossum (Didelphis albiventris Lund, 1840) and porcupine (Sphiggurus villosus Cuvier, 1823). Rope bridges with the highest number of species recorded had more forest cover and lower urban area around them than overpasses little used. Our results indicate that overpasses, in Porto Alegre, work as a linear corridor between forest remnants, although the outcomes for individual survival, group persistence, population demography or gene flow have not been measured. Furthermore, canopy bridges may be important to mitigate the impact of roads and power lines on wildlife, but electric cables also need to be completely isolated when present, to warrant animals' physical integrity.

Human interventions in natural environments are the main cause of biodiversity loss worldwide. The situation is not different in southern Brazil, home of five primate species. Although some earlier studies exist, studies on the primates of this region began to be consistently carried out in the 1980s and have continued since then. In addition to important initiatives to study and protect the highly endangered Leontopithecus caissara Lorrini & Persson, 1990 and Brachyteles arachnoides E. Geoffroy, 1806, other species, including locally threatened ones, have been the focus of research, management, and protection initiatives. Since 1993, the urban monkeys program (PMU, Programa Macacos Urbanos) has surveyed the distribution and assessed threats to populations of Alouatta guariba clamitans (Cabrera, 1940) in Porto Alegre and vicinity. PMU has developed conservation strategies on four fronts: (1) scientific research on biology and ecology, providing basic knowledge to support all other activities of the group; (2) conservation education, which emphasizes educational presentations and long-term projects in schools near howler populations, based on the flagship species approach; (3) management, analyzing conflicts involving howlers and human communities, focusing on mitigating these problems and on appropriate relocation of injured or at-risk individuals; and finally, (4) Public Policies aimed at reducing and/or preventing the impact of urban expansion, contributing to create protected areas and to strengthen environmental laws. These different approaches have contributed to protect howler monkey populations over the short term, indicating that working collectively and acting on diversified and interrelated fronts are essential to achieve conservation goals. The synergistic results of these approaches and their relationship to the prospects for primatology in southern Brazil are presented in this review.