Nilton Cáceres

• PhD
• Full Professor at Federal University of Santa Maria

Aim: Because of their recent evolutionary radiation, capuchin monkeys represent an ideal group with which to investigate ecomorphological adaptations in relation to geography and climate. Our aim was to identify patterns of both skull size and shape variation in capuchins in relation to environmental variables and latitude. Location: Tropical and s...

Marmosa rapposa and Thylamys sponsorius were captured in syntopy in the locality of Isla de Cañas Salta province, Argentina. We studied the stomach contents of 7 M. rapposa and 10 T. sponsorius and identified arthropods and plant material as the main items. Niche overlap was studied using the Pianka index. We found that arthropods were the most abu...

Aim Animal coloration varies in response to environmental conditions. One well‐known principle, Gloger's rule, suggests that warmer and wetter environments lead to more pigmented animals. Yet, the original formulation lacks differentiation between the two primary melanin pigments: eumelanin and pheomelanin. We examined spatial eumelanin and pheomel...

This chapter introduces the book by telling how the history of research on American and Australasian marsupials has developed up to now. It focuses on the main disciplines that aim to study the diversity of marsupials and other metatherians, from the past to today. These disciplines are taxonomy, systematics, biogeography, ecology, and conservation...

Adaptations to functional demands improve survival and fitness in animals. Depending on the trait, its variation can be related to several different evolutionary and ecological trends, often being explained by a combination of intrinsic (allometry, integration, and stochastic events) and extrinsic factors (biological interactions and environmental...

The American marsupials have been consistently reported to present a highly integrated and conserved morphology. This has been repeatedly argued as one of the main reasons why marsupial morphology is not as diverse as other mammals. Here we explore if these animals present specific mandibular ecomorphs, while also comparing the tempo of evolution a...

There are strong physiological and behavioral differences that allow animals to live in forests versus savannas. For example, terrestrial forest-dwelling mammals tend to be small compared to species living in savannas. Robust capuchin monkeys (genus Sapajus) are widespread in tropical South America, occurring in both forest and savanna environments...

Marsupials have a long evolutionary history of diversification in the Southern Hemisphere, where they expanded geographic distribution from America through Antarctica, reaching Australasia. American and Australasian marsupials have mostly evolved and diversified independently, albeit sharing some evolutionary patterns of morphological variation. Ba...

The focus of research and conservation in tropical regions is mainly devoted to forest ecosystems, usually neglecting the processes underlying widespread, more open biomes, like savannas. Here we test a wide range of sampled woodland sites across the South American savanna for the direct and indirect effects of habitat loss and vegetation density o...

Social behavior studies in mammals are commonly found in the literature. However, nothing is known on the hierarchical relationships of American marsupials, which are mainly composed of cryptic, nocturnal species. We aim to examine the existence of a domination and subordination relationship among Didelphis aurita females. For such purpose, we used...

When studying landscapes, defining the scale implies gains and losses of information associated with the choices of resolution and extent needed to understand a given phenomenon. Whereas the local scale is able to provide a more accurate understanding of local dynamics, the global scale able to provide a broader understanding of regional dynamics,...

Many animal species participate in interspecific groups which can provide benefits such as better detection of predator presence, but may also lead to costs such as interspecific competition. In interspecific groups, species with particular functional traits should be aggregated in a way that maximizes the benefits and minimizes the costs of these...

The spatial distribution of biodiversity is driven by species dispersal and their response to the environment. Therefore, diversity patterns should differ across taxonomic groups depending on differences in traits associated with dispersal, metabolism, and foraging. We compared the distribution of rodents and marsupials in the Atlantic forest and i...

Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mou...

Although many studies have shown that species richness increases from high to low latitudes (the latitudinal diversity gradient), the mechanisms responsible for generating and maintaining higher species richness in the tropics remain intensely debated. Here, we investigate how the effects of temperature on speciation rates (kinetic effects) and the...

Small mammal assemblages from South America provide a unique opportunity to measure coexistence and niche partitioning between marsupials and placentals. We tested how these two major clades partition environmental resources by comparing stable isotopic ratios of similar sized Didelphidae and Sigmodontinae in four Brazilian biomes: Pampas grassland...

Geographical barriers, distance, and environmental gradients may determine variation in species composition of bat assem- blages in tropical regions. For example, bats assume a wide variety of foraging strategies, dietary traits, diferent light abili- ties, and New World leaf-nosed bats (Phyllostomidae) are among the most functionally diverse famil...

Three species of sexually-dimorphic opossums are broadly distributed across South America: the habitat generalist Didelphis albiventris, the Atlantic forest-dweller D. aurita, and the Amazonian forest-dweller D. marsupialis. We used 2D geometric morphometrics to quantify skull size and shape variation in the three opossum species and test the hypot...

Aim Bergmann's rule is an ecogeographical rule that describes a negative relationship between body size and temperature. Here, we used a multivariate measure of skull size (centroid size) as a proxy for body size to test the influence of temperature, precipitation, elevation, human influence and competition on size in Dicotyles tajacu and Tayassu p...

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...

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 Neotropica...

The effects of habitat fragmentation on different taxa and ecosystems are subject to intense debate, and disentangling them is of utmost importance to support conservation and management strategies. We evaluated the importance of landscape composition and configuration, and spatial heterogeneity to explain α‐ and β‐diversity of mammals across a gra...

Geographical distribution of color phenotypes and associations with ecological predictors remains poorly understood. An important geographic pattern concerning this topic is Gloger’s rule, which predicts the increase of pigmentation in endothermic animals from cold and dry to warm and wet environments. Didelphid marsupials exhibit a variety of colo...

Variation in the spatial structure of communities in terms of species composition (beta diversity) is affected by different ecological processes, such as environmental filtering and dispersal limitation. Large rivers are known as barriers for species dispersal (riverine hypothesis) in tropical regions. However, when organisms are not dispersal limi...

S1 Video. Typical alert display showing the white marks on the posterior surface of the ears in Southern tigrina

Melanism in the cat family has been associated with functions including camouflage, thermoregulation and parasite resistance. Here we investigate a new hypothesis proposing that the evolution of melanism in cats has additionally been influenced by communication functions of body markings. To evaluate this hypothesis, we assembled a species-level da...

Melanism in the cat family has been associated with functions including camouflage, ther-moregulation and parasite resistance. Here we investigate a new hypothesis proposing that the evolution of melanism in cats has additionally been influenced by communication functions of body markings. To evaluate this hypothesis, we assembled a species-level d...

It is not a new concept that marsupials and placentals are distant and distinct clades among mammals. In South America, these animals coexist, occupy similar niches and, in some cases, are similar in appearance. This is especially true with respect to the locomotor categories of smaller rodents belonging to the family Cricetidae or, more specifical...

Biodiversity inventories contain important information about species richness, community structure, and composition, and are the first step in developing any conservation and mitigation strategies. The Atlantic Forest of South America is home to around 334 species of small‐, medium‐, and large‐sized mammals, and is currently restricted to less than...

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...

A primary requirement of the mammalian skull is to exert forces on different foods and to resist the forces imposed on it during feeding. Skull shape patterns within and among mammals are generally well known, but the biomechanical relevance of this variation remains limited for some groups. By integrating geometric morphometric and biomechanical a...

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...

Movements under environmental structures and on supports, and the use of shelters by Akodon montensis were assessed using the spool-and-line technique. Movements of a few individuals of Thaptomys nigrita , Brucepattersonius iheringi and Oligoryzomys nigripes were also assessed and briefly described. Akodon montensis often used fallen logs, lianas a...

Litter size in mammals can be influenced by morphological and environmental variables. Among mammals, the family Didelphidae includes a diverse group of New World endemic marsupials, with extensive records of variation in litter size across species. The aim of this study was to assess factors that influence litter size variation in didelphid marsup...

Habitat quality and its availability affect the structure of communities at a variety of different spatial and environmental scales, including habitat and landscape levels. Analyses conducted at multiple scales have demonstrated the importance of landscape patterns with regard to community structure. We used a multi-scale approach to better underst...

Groups of species that are widely distributed along an environmental gradient can exhibit adaptations and plasticity, resulting from susceptibility to different pressures. Certain groups of rodents and rabbits that are distributed throughout the Neotropical region are ideal models to evaluate such trait changes. Using geometric morphometric procedu...

The latitudinal diversity gradient is the most well-known ecological pattern. Several hypotheses have been proposed to explain this biodiversity gradient. However, the predictors of species richness at continental scales may have different effects at regional scales, and even lose importance. Here we tested the effects of climate, energy, and habit...

Knowledge about the feeding ecology of didelphid marsupials remains incipient, especially in environments with marked seasonality in resource supply, such as in the Cerrado. We analysed the diet composition of Thylamys macrurus in Cerrado patches in central-western Brazil. We also evaluated seasonal and sexual variation in the species’ diet, as wel...

Xenarthra is one of the most peculiar mammalian groups to have originated in South America, where most of its evolutionary history has taken place. Xenarthrans have experienced significant climatic changes and also geographical isolation for most of the Cenozoic. Thus, the cranial morphology of xenarthrans may reflect the different pressures that t...

Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from 5.83 to 29.75 decimal degrees of latitude and 34.82 to 56.73 decimal degrees of lon- gitude in the Atlantic forest of South America. We present trait information from 16,840 individ- uals of...

Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species,...

Howler monkeys (genus Alouatta) are large folivorous primates living in South America. We tested for the application of both Rensch's rule and Bergmann's rule to body size variation in Alouatta. We found that Rensch's rule does apply in howlers. In Alouatta, males exploit dominance rank competition, and take advantage from seasonal abundance of hig...

Habitat fragmentation reduces biodiversity and affects ecological processes that are fundamental for maintaining ecosystem services. We investigated how landscape structure—percent forest cover, patch density, percent cover by edge, perimeter-area ratio, and spatial heterogeneity—affects the diversity of mammalian carnivores at multiple extents wit...

Neotropical primates are among the most well studied forest mammals concerning their population densities. However, few studies have evaluated the factors that influence the spatial variation in the population density of primates, which limits the possibility of inferences towards this animal group, especially at the landscape-level. Here, we compi...

We evaluated several factors that might be related to the home-range size of felids at both inter and intraspecific levels. At the interspecific level, we tested the influence of body mass on home range size of 19 felid species, while controlling for phylogeny. At the species level, we evaluated the effect of sex and habitat type (open vs. closed)...

El objetivo de este estudio fue evaluar los factores que influyen en el tamaño del ámbito hogareño de felinos en los niveles inter- e intraespecífico. En nivel interespecífico, evaluamos la influencia de la masa corporal en el ámbito hogareño de 19 especies de felinos, controlando la filogenia. A nivel de especies, evaluamos el efecto del sexo y el...

According to the habitat amount hypothesis the species richness in a sample site should increase with the habitat amount in the local landscape around the sample site. On the other hand, size and isolation of the patch containing the sample site should have no effect on species richness if the habitat amount in the local landscape remains constant....

Environmental pressures are key mechanisms in the change of size or shape of an organism. In addition to external factors, the pressure of allometry (size-related shape changes) can also be present itself in the way that shape varies even in adulthood. In this study, we used a geometric morphometric approach to analyse skull size and shape variatio...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

Figure S1: Database schema. Diversity data in yellow, GIS data in green and Catalogue of Life data in blue. The diversity tables datasource, study, site, measuredtaxon and diversitymeasurement follow the structure described in ‘Methods’ in the main text and in Hudson et al. (2014): a datasource is associated with one or more study records, each of...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

The use of space in mammals may vary according to sexual dimorphism, mating system and territorial behavior in order to ensure optimization of the reproductive success of each sex and the interactions with other species. In the present study, the determinants of home range (HR) size of males and females of Gracilinanus agilis (Burmeister 1854) were...

This study aimed to evaluate exposure of wild small mammals to spotted fever group (SFG) rickettsiae in Mato Grosso do Sul State, central-western Brazil. Serum samples of 68 small mammals were analyzed by indirect immunofluorescence assay (IFA) against six Rickettsia species from Brazil. Overall, 37.5% (9/24) marsupials and 6.8% (3/44) small rodent...

This study aimed to assess the contribution of hosts characteristics (rodents and marsupials) in the organization of ectoparasite communities present in woodland patches in western central Brazil. We verified the effect of host species, sex, body mass and vertical strata in addition to the role of seasonality on the ectoparasite composition, richne...

The influence of the environment on the geographical variation of morphological traits has been recognized in a number of taxa. Pecari tajacu and Tayassu pecari are ideal models to investigate intraspecific geographic variation in skull because of their wide and heterogeneous geographical distribution in South America. We used geometric morphometri...

Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allo-patric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology...

Full morphometric data used in this study. (XLSX)

Variation partitioning with Didelphis aurita skull shape as dependent variable and size, sex and geography as dependent variables. P values tests for the significance of F after 1000 permutations. Significance is highlighted. (DOCX)

Ecological Niche Models comparison analyses procedures to test for coordinates accuracy and error. (DOCX)

Maps showing the climatic suitability for the White-eared Opossum, D. albiventris (at the top), and for the Brazilian Common Opossum, D. aurita (at bottom) in South America based on an ensemble approach showing differences in the prediction when using only GPS data (at left) and using all data available (at right). Green indicates high climatic sui...

Variation partitioning with Didelphis skull shape as dependent variable and taxonomy, size, sex and geography as dependent variables. P values tests for the significance of F after 1000 permutations. Significance is highlighted. (DOCX)

Boxplot with AUC and Boyce Index (BI) values of both train (at left) and test data (at right) for each algorithm used to build the niche models for the White-eared Opossum (Didelphis albiventris) and the Brazilian Common Opossum (D. aurita). Dark bar indicates the mean, box represents the standard deviation and whiskers represent the maximum and mi...

Didelphis albiventris and D. aurita records, separated by species, source and coordinates. (DOCX)

Didelphis albiventris and D. aurita specimens used for morphological analyses, separated by museum record, species, sex, geographical coordinates (in decimal degrees) and geography. (DOCX)

Variation partitioning with Didelphis albiventris skull shape as dependent variable and size, sex and geography as dependent variables. P values tests for the significance of F after 1000 permutations. Significance is highlighted. (DOCX)

Species morphological changes can be mutually influenced by environmental or biotic factors, such as competition. South American canids represent a quite recent radiation of taxa that evolved forms very disparate in phenotype, ecology and behaviour. Today, in the central part of South America there is one dominant large species (the maned wolf, Chr...

In South America, the crab-eating fox Cerdocyon thous occurs in sympatry to the ecologically similar, and phylogenetically close Lycalopex vetulus to the North, and Lycalopex gymnocercus to the South of its range. We studied character displacement in Cerdocyon under the effect of Bergmann’s rule and the presence (or absence either) of Lycalopex wit...

A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assemb...

The distributional data of mammalian fauna are important to reach a comprehensive overview of biogeographic patterns and to highlight regional conservation status, especially in a poorly known region such as the Chiquitano dry forest in western Brazil. Our aims were to survey the mammal species occurring in the Urucum Mountains, located in the sout...

Tribosphenic molars are considered great innovations in mammals and are related to several structures and variables that can explain adaptation. The aim of this study was to investigate the importance of body size and habitat relation, using a phylogenetic approach, in the first lower molar shape in didelphid marsupials. Geometric morphometric anal...

AimTo compare the fit of models of climate, habitat quality, neutral processes, and geometric constraints to species richness and composition of small mammal assemblages.LocationThe South American Atlantic Forest biome.Methods Using neutral models and mid-domain effect models, we simulated species spread in a spatially explicit array of grid cells...

A região sul do Brasil é uma das menos conhecidas quanto à distribuição de sua mastofauna. Em função dessa carência, podem ser úteis algumas informações inéditas sobre a distribuição dos mamíferos terrestres nessa região tão rica em formações vegetais. A partir de um criterioso levantamento de dados realizado em coleções científicas, literatura e p...

Chewing on different food types is a demanding biological function. The classic assumption in studying the shape of feeding apparatuses is that animals are what they eat, meaning that adaptation to different food items accounts for most of their interspecific variation. Yet, a growing body of evidence points against this concept. We use the primate...

We describe ectoparasite fauna associated with small mammals in fragments of Cerrado biome, central-western Brazil. We analyzed the level of associations and the aggregation patterns according to seasonal and host variations. Small mammals were systematically captured in 54 woodland fragments from February 2012 to July 2013. A total of 1040 animals...

The present study describes ticks associated with small mammals and analyzes the aggregation patterns according to seasonal and host variations in the Cerrado biome, central-western Brazil. Small mammals were systematically captured in 54 woodland fragments from February 2012 to July 2013. A total of 1,040 animals belonging to eight marsupial and 1...

Large islands near the mainland tend to have greater species richness than smaller or remote oceanic islands. This study aimed to compare the community of Phyllostomidae bats on the island of Maracá-Jipioca, in Amapá, northern Brazil, and on the adjacent mainland. We also compared the community in four vegetation types present in both areas. Sampli...

How dispersal, environmental filters, and local extinctions affect species diversity depends on the species requirements for habitat, dispersal limitations, and abundance. Few studies have been able to properly separate these processes and to show how they affect the beta diversity patterns for multiple organisms. We investigated how the compositio...

Our aim is to identify ecomorphological adaptations in the skull shape of the South American howler monkeys (species of the genus Alouatta, Lacépède, 1799, Primates, Atelidae). Since Alouatta is relatively homogenous in feeding ecology, we expect skull shape variation to be relatively conservative across species. We used geometric morphometrics to...

A two year study of dung beetles and ants acting on scats of two species of opossum (Didelphis spp.) was carried out. Scats were left in the field in order to detect post-dispersal agents. A portion of each scat (30 %) was examined for seeds in the laboratory. Beetles were recovered from burrows (51 % of 84 faecal samples left in the field) where t...

The impact of environmental variation on phenotypic diversification is one major issue in evolutionary studies. Environmental variation is thought to be a primary factor in evolution, especially at high latitudes. In contrast, tropical areas are traditionally viewed as the cradle where the long-term effects of biological interactions on phenotypic...

Blue Manakin Chiroxiphia caudata (Pipridae) has a lek mating system in which males cooperate in teams of two or more individuals for courtship displays to females. Males ascend through a dominance hierarchy to assume the rank of alpha male. Only alpha males copulate with females. In this study, we describe the ascension of a male to the alpha rank...

Didelphis aurita and D. albiventris are widely distributed in South America, with a range of sympatry in the limit of their distribution, particularly in Araucaria mixed ombrophilous forest in the southern Atlantic Forest. We investigated the spatial, feeding, and time use between these morphologically similar species in a remnant of Araucaria fore...