Camera trap surveys of Atlantic Forest mammals: A data set for analyses considering imperfect detection (2004-2020)

Camera traps became the main observational method of a myriad of species over large areas. Data sets from camera traps can be used to describe the patterns and monitor the occupancy, abundance, and richness of wildlife, essential information for conservation in times of rapid climate and land-cover changes. Habitat loss and poaching are responsible for historical population losses of mammals in the Atlantic Forest biodiversity hotspot, especially for medium to large-sized species. Here we present a data set from camera trap surveys of medium to large-sized native mammals (>1 kg) across the Atlantic Forest. We compiled data from 5380 ground-level camera trap deployments in 3046 locations, from 2004 to 2020, resulting in 43,068 records of 58 species. These data add to existing data sets of mammals in the Atlantic Forest by including dates of camera operation needed for analyses dealing with imperfect detection. We also included, when available, information on important predictors of detection, namely the camera brand and model, use of bait, and obstruction of camera viewshed that can be measured from example pictures at each camera location. Besides its application in studies on the patterns and mechanisms behind occupancy, relative abundance, richness, and detection, the data set presented here can be used to study species' daily activity patterns, activity levels, and spatiotemporal interactions between species. Moreover, data can be used combined with other data sources in the multiple and expanding uses of integrated population modeling. An R script is available to view summaries of the data set. We expect that this data set will be used to advance the knowledge of mammal assemblages and to inform evidence-based solutions for the conservation of the Atlantic Forest. The data are not copyright restricted; please cite this paper when using the data.

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans-anteaters, sloths, and armadillos-have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.

Diet overlap and spatial segregation between two neotropical marsupials revealed by multiple analytical approaches

Species co-existence depends on how organisms utilize their environment and resources. When two sympatric species are similar in some ecological requirements, their coexistence may arise from differences in resource use over time and/or space. Interactions among coexisting marsupials remain poorly understood, especially in the Neotropics. Here we combine spatial niche measurements, individual-resource networks, and isotopic niche approaches, to investigate the ecological strategies used by the Neotropical marsupials Didelphis aurita and Metachirus nudicaudatus to co-occur in an area of Serra do Mar State Park (southeast of Brazil). Both individual-resource networks and isotopic niche approaches indicate similar patterns of omnivory for both species. Isotopic analysis showed the species’ trophic niche to be similar, with 52% of overlap, and no differences between proportional contributions of each resource to their diets. Moreover, individual-resource network analysis found no evidence of diet nestedness or segregation. The trophic niche overlap observed was associated with spatial segregation between species. Despite using the same area over the year, D. aurita and M. nudicaudatus exhibited spatial segregation among seasons. These results illustrate that the detection of spatial segregation is scale-dependent and must be carefully considered. In conclusion, our findings provide a new perspective on the ecology of these two Neotropical marsupials by illustrating how the association of distinct but complementary methods can be applied to reach a more complete understanding of resource partitioning and species coexistence.

Feeding ecology and activity pattern of black-fronted titi monkeys (Callicebus nigrifrons) in a semideciduous tropical forest of southern Brazil

Most aspects of the ecology and behavior of Callicebus nigrifrons are still unknown. The information available about this species is mainly based on a few studies that also focused on other Callicebus. We examined the feeding behavior and activity pattern of a free-ranging pair of C. nigrifrons between March and November 2007 in an area of semideciduous tropical forest of southeastern Brazil. The study site is located at the southern limit of the Tropical Zone and is characterized by pronounced seasonality. As observed for other Callicebus monkeys, fruits were the most consumed food resource, accounting for 53% of the diet, which was complemented mainly by leaves (16%) but also by invertebrates and flowers (10% of each). A great variety of plant families (28) and species (62) were included in the diet. The titis spent 35% of their time feeding, distributing the remaining time between resting (30%) and traveling (24%). Data presented here indicate that C. nigrifrons prefer high-quality food items (fruit pulp), adding low-quality food items (such as leaves) as the availability of the higher-quality foods decreases. The amount of time spent traveling and resting did not change between seasons, but the time invested in feeding increased during the lean period. The activity pattern was not related to fruit availability, but in months with lower temperatures, monkeys spent more time feeding. We suggest that the feeding ecology and activity pattern of C. nigrifrons reflect adaptations related to annual fluctuations in food availability and temperature, respectively.

Potential seed dispersal by Didelphis albiventris (Marsupialia, Didelphidae) in highly disturbed environment

Urban forests are usually isolated and highly disturbed, however they are important shelters for tolerant animal species. Their food habits expose the different ecological roles these animals perform in the habitat. We analyzed the contribution of Didelphis albiventris Lund (1840), as a seed disperser, to the vegetation renewal of an urban forest fragment, describing its frugivorous diet and testing the viability of ingested seeds. Both male and female of white-eared opossum included a vast variety of items in their diet, mainly invertebrates and fruits. Fruits were consumed during all year round and seasonality was not observed. The majority of consumed fruits was from pioneer plant species, which is common in disturbed areas, in accordance to the opossum's opportunistic habits. The viability of ingested seeds, evaluated by linear logistic regression models applied to data from germination tests, was different of the seeds collected directly from ripe fruits; it varied among species, maybe due to the intrinsic characteristics of plant species. As a highly generalist species, D. albiventris can inhabit disturbed environments and then disperse seeds from pioneer plants, where the vegetation must be restored. It is crucial that this process does not depend only on the specialist frugivores, which are frequently absent in urban forest fragments. Therefore, the presence of generalist species of secondary environments has its importance emphasized.