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.

As armadilhas fotográficas tornaram­se o principal método de observação de muitas espécies em grandes áreas. Os dados obtidos com armadilhas fotográficas podem ser usados para descrever os padrões e monitorar a ocupação, abundância e riqueza da vida selvagem, informação essencial para a conservação em tempos de rápidas mudanças climáticas e de cobertura do solo. A perda de habitat e a caça furtiva são responsáveis pelas perdas populacionais históricas de mamíferos no hotspot de biodiversidade da Mata Atlântica, especialmente para espécies de médio e grande porte. Aqui apresentamos um conjunto de dados de levantamentos com armadilhas fotográficas de mamíferos de médio e grande porte (>1 kg) em toda a Mata Atlântica. Compilamos dados de 5.380 armadilhas fotográficas instaladas no nível do chão em 3.046 locais, de 2004 a 2020, resultando em 43.068 registros de 58 espécies. Esses dados acrescentam aos conjuntos de dados existentes de mamíferos na Mata Atlântica por incluir as datas de operação das câmeras, que são necessárias para análises que lidam com detecção imperfeita. Também incluímos, quando disponíveis, informações sobre importantes preditores de detecção, como marca e modelo da câmera, uso de isca e obstrução do visor da câmera que pode ser medido a partir de imagens de exemplo em cada local da câmera. Além de estudos sobre os padrões e mecanismos por trás da ocupação, abundância relativa, riqueza e detecção, o conjunto de dados aqui apresentado pode ser usado para estudar os padrões de atividade diária das espécies, nível de atividade e interações espaço­temporais entre as espécies. Além disso, os dados podem ser usados em combinação com outras fontes de dados em diversas análises com modelagem populacional integrada. Um script R está disponível para visualizar um resumo do conjunto de dados. Esperamos que este conjunto de dados seja usado para aumentar o conhecimento sobre as assembleias de mamíferos e usado para informar soluções baseadas em evidências para a conservação da Mata Atlântica. Os dados não são restritos por direitos autorais e, por favor, cite este documento ao usar os dados.

AMAZONIA CAMTRAP: A data set of mammal, bird, and reptile species recorded with camera traps in the Amazon forest.

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data.

Potential Movement Corridors and High Road-Kill Likelihood do not Spatially Coincide for Felids in Brazil: Implications for Road Mitigation.

The negative effects of roads on wildlife populations are a growing concern. Movement corridors and road-kill data are typically used to prioritize road segments for mitigation measures. Some research suggests that locations where animals move across roads following corridors coincide with locations where they are often killed by vehicles. Other research indicates that corridors and road-kill rarely occur in the same locations. We compared movement corridor and road mortality models as means of prioritizing road segments for mitigation for five species of felids in Brazil: tiger cats (Leopardus tigrinus and Leopardus guttulus were analyzed together), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yagouaroundi), and puma (Puma concolor). We used occurrence data for each species and applied circuit theory to identify potential movement corridors crossed by roads. We used road-kill records for each species and applied maximum entropy to determine where mortality was most likely to occur on roads. Our findings suggest that movement corridors and high road mortality are not spatially associated. We suggest that differences in the behavioral state of the individuals in the species occurrence and road-kill data may explain these results. We recommend that the road segments for which the results from the two methods agree (~5300 km for all studied species combined at 95th percentile) should be high-priority candidates for mitigation together with road segments identified by at least one method in areas where felids occur in low population densities or are threatened by isolation effects.

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics.

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 (peer-reviewed 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 large-scale 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.

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics.

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.

Simulating the Consequences of Roads for Wildlife Population Dynamics.

Rapidly expanding road networks have been a key driver of the fragmentation and isolation of many wildlife species, and are a source of significant mortality due to collisions with vehicles. But not all animals are affected equally by transportation infrastructure, and in most cases little is known about the population-scale consequences of roads for wildlife. Even less information is available to characterize species' behavioral responses to roads. Although research shows that maned wolves (Chrysocyon brachyurus) in Brazil are experiencing considerable fragmentation and road mortality, the degree to which these disturbances are impacting the species' viability is unknown. The goal of this study was to analyze the potential effects of roads on maned wolf population size and structure. We used a simulation model to evaluate the population-scale consequences of individual maned wolf interactions with roads, which can result in road crossing, avoidance, or mortality due to a collision with a vehicle. We also forecasted where in Brazil these impacts might be most significant. Our model incorporated species demographic and movement parameters, plus habitat quality and a map of the road network. We found that even moderate rates of road mortality led to severe declines in population size, and that four specific locations accounted for a disproportionate fraction of roadkill events. Our approach will be generally useful for evaluating the relative importance of road effects on species conservation in many ecological systems, for prioritizing data collection efforts, and for informing conservation policies and mitigation strategies.

Neotropical carnivores: a data set on carnivore distribution in the Neotropics

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.

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.

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America.

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1-6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.

BRAZIL ROAD-KILL: a data set of wildlife terrestrial vertebrate road-kills.

Mortality from collision with vehicles is the most visible impact of road traffic on wildlife. Mortality due to roads (hereafter road-kill) can affect the dynamic of populations of many species and can, therefore, increase the risk of local decline or extinction. This is especially true in Brazil, where plans for road network upgrading and expansion overlaps biodiversity hotspot areas, which are of high importance for global conservation. Researchers, conservationists and road planners face the challenge to define a national strategy for road mitigation and wildlife conservation. The main goal of this dataset is a compilation of geo-referenced road-kill data from published and unpublished road surveys. This is the first Data Paper in the BRAZIL series (see ATLANTIC, NEOTROPICAL, and BRAZIL collections of Data Papers published in Ecology), which aims make public road-kill data for species in the Brazilian Regions. The dataset encompasses road-kill records from 45 personal communications and 26 studies published in peer-reviewed journals, theses and reports. The road-kill dataset comprises 21,512 records, 83% of which are identified to the species level (n = 450 species). The dataset includes records of 31 amphibian species, 90 reptile species, 229 bird species, and 99 mammal species. One species is classified as Endangered, eight as Vulnerable and twelve as Near Threatened. The species with the highest number of records are: Didelphis albiventris (n = 1,549), Volatinia jacarina (n = 1,238), Cerdocyon thous (n = 1,135), Helicops infrataeniatus (n = 802), and Rhinella icterica (n = 692). Most of the records came from southern Brazil. However, observations of the road-kill incidence for non-Least Concern species are more spread across the country. This dataset can be used to identify which taxa seems to be vulnerable to traffic, analyze temporal and spatial patterns of road-kill at local, regional and national scales and also used to understand the effects of road-kill on population persistence. It may also contribute to studies that aims to understand the influence of landscape and environmental influences on road-kills, improve our knowledge on road-related strategies on biodiversity conservation and be used as complementary information on large-scale and macroecological studies. No copyright or proprietary restrictions are associated with the use of this data set other than citation of this Data Paper.

Carcass Persistence and Detectability: Reducing the Uncertainty Surrounding Wildlife-Vehicle Collision Surveys.

Carcass persistence time and detectability are two main sources of uncertainty on roadkill surveys. In this study, we evaluate the influence of these uncertainties on roadkill surveys and estimates. To estimate carcass persistence time, three observers (including the driver) surveyed 114km by car on a monthly basis for two years, searching for wildlife-vehicle collisions (WVC). Each survey consisted of five consecutive days. To estimate carcass detectability, we randomly selected stretches of 500m to be also surveyed on foot by two other observers (total 292 walked stretches, 146 km walked). We expected that body size of the carcass, road type, presence of scavengers and weather conditions to be the main drivers influencing the carcass persistence times, but their relative importance was unknown. We also expected detectability to be highly dependent on body size. Overall, we recorded low median persistence times (one day) and low detectability (<10%) for all vertebrates. The results indicate that body size and landscape cover (as a surrogate of scavengers' presence) are the major drivers of carcass persistence. Detectability was lower for animals with body mass less than 100g when compared to carcass with higher body mass. We estimated that our recorded mortality rates underestimated actual values of mortality by 2-10 fold. Although persistence times were similar to previous studies, the detectability rates here described are very different from previous studies. The results suggest that detectability is the main source of bias across WVC studies. Therefore, more than persistence times, studies should carefully account for differing detectability when comparing WVC studies.

Molecular assessment of the phylogeny and biogeography of a recently diversified endemic group of South American canids (Mammalia: Carnivora: Canidae).

To investigate the evolution and biogeography of an endemic group of South American foxes, we examined mitochondrial DNA control region sequences for 118 individuals belonging to all six extant species of the genus Lycalopex. Phylogenetic and molecular dating analyses supported the inference that this genus has undergone a very recent and rapid radiation, stemming from a common ancestor that lived ca. 1 million years ago. The Brazilian endemic L. vetulus was supported as the most basal species in this genus, whereas the most internal group is comprised by the recently diverged (ca. 350,000 years ago) Andean/Patagonian species L. griseus and L. culpaeus. We discuss the inferred phylogenetic relationships and divergence times in the context of the current geographic distributions of these species, and the likely effects of Pleistocene climatic changes on the biogeography of this group. Furthermore, a remarkable finding was the identification of multiple individuals classified as L. gymnocercus bearing mtDNA haplotypes clearly belonging to L. griseus, sampled in regions where the latter is not known to occur. At a minimum, this result implies the need to clarify the present-day geographic distribution of each of these fox species, while it may also indicate an ongoing hybridization process between them. Future testing of this hypothesis with in-depth analyses of these populations is thus a priority for understanding the history, evolutionary dynamics and present-day composition of this endemic Neotropical genus.

Seasonality and habitat types affect roadkill of neotropical birds.

Roadkills are amongst the most significant biodiversity impacts, although little is known about the factors which influence the roadkill of neotropical birds. Hence, the objective was to evaluate differences in roadkill richness and rates for neotropical birds according to the seasons of the year and habitat types associated with roads. The data was collected along two federal highways, in southern Brazil. We identified 57 roadkilled species, for a mean roadkill rate of 0.06 ind./km/day (Min.=0.009; Max.=0.47). Our results demonstrate that richness and roadkill rates change according to seasonality and habitat types. Roadkills were concentrated in rice fields and wetlands, intensifying both in richness and rates during the summer and autumn. Nearby areas have similar roadkill rates, independent of habitat types. This probably occurs due to the movement of several species seeking food and shelter. Juvenile dispersion, harvest and grain transportation periods, as well as flight and foraging behaviors over road lanes seem to be related to the increasing roadkill occurrences and richness regarding more abundant species. However, given the elevated number of occasionally roadkilled species (more than 70% with N<5), we believe that highway surface and traffic act as physical barriers which inhibit the movement of many species which either present occasional roadkills or none at all.

Influence of sampling effort on the estimated richness of road-killed vertebrate wildlife.

Road-killed mammals, birds, and reptiles were collected weekly from highways in southern Brazil in 2002 and 2005. The objective was to assess variation in estimates of road-kill impacts on species richness produced by different sampling efforts, and to provide information to aid in the experimental design of future sampling. Richness observed in weekly samples was compared with sampling for different periods. In each period, the list of road-killed species was evaluated based on estimates the community structure derived from weekly samplings, and by the presence of the ten species most subject to road mortality, and also of threatened species. Weekly samples were sufficient only for reptiles and mammals, considered separately. Richness estimated from the biweekly samples was equal to that found in the weekly samples, and gave satisfactory results for sampling the most abundant and threatened species. The ten most affected species showed constant road-mortality rates, independent of sampling interval, and also maintained their dominance structure. Birds required greater sampling effort. When the composition of road-killed species varies seasonally, it is necessary to take biweekly samples for a minimum of one year. Weekly or more-frequent sampling for periods longer than two years is necessary to provide a reliable estimate of total species richness.

Priority ranking of road sites for mitigating wildlife roadkill / Hierarquização de quilômetros prioritários à mitigação de atropelamentos de animais selvagens

We propose a ranking index to assign priorities to sites for implementation of measures to mitigate wildlife roadkill. We conducted a case study along 34 km of highway BR 392 in Southern Brazil. We compared priority sites established only according to roadkill rates, with those defined by our index. The index used four parameters: the richness of target species, diversity of roadkilled species, roadkill rate of target species, and presence of endangered species. Although it is impossible to protect the entire community of vertebrates affected by roadkill, we defined nine target species, five mammals and four reptiles. For each parameter, we defined coefficients ranging between 0 and 3. There was a significant change in the priorities of sites for implementing mitigation devices, which caused changes in the species that were protected. The definition of priority sites by considering only the roadkill rate protected reptiles especially, to the detriment of all mammal species, including endangered species. Sites with high roadkill rates continued to be among the most important for conservation, but the index diluted the effect of this parameter, changing the ranking. This ranking index can be an effective tool to aid government institutions in decision-making, especially when more elaborate analyses are not feasible for reasons of time, resources, or lack of trained personnel.

Propomos um índice para a definição de trechos prioritários à implantação de medidas de mitigação contra atropelamento de animais selvagens. Conduzimos um estudo de caso em 34 km da rodovia BR 392, no Sul do Brasil. Comparamos trechos prioritários definidos somente com taxas de atropelamento e trechos prioritários definidos pelo índice. O índice se utilizou de 4 parâmetros: riqueza de espécies alvo, diversidade total de espécies atropeladas, taxa de atropelamento de espécies atropeladas e presença de espécies ameaçadas. Considerando ser impossível proteger toda a comunidade de vertebrados afetada por atropelamento definimos 9 espécies alvo, 5 mamíferos e 4 répteis. Para cada parâmetro foram definidos coeficientes com valores entre 0 e 3. Houve uma significativa mudança nos trechos prioritários para implantação de aparatos de mitigação, alterando as espécies que foram protegidas. Os trechos, definidos somente pela taxa de atropelamento, protegeram especialmente répteis, em detrimento de todos os mamíferos, incluindo as espécies ameaçadas. Trechos com altas taxas de atropelamento continuaram entre os mais importantes para conservação, mas o índice diluiu o efeito deste parâmetro, alterando sua prioridade. O índice pode ser uma ferramenta efetiva para a tomada de decisão em instituições governamentais, especialmente quando análises mais elaboradas não são viáveis em razão de tempo, recursos ou ausência de pessoal especializado.

Estrutura populacional de capivaras na Estação Ecológica do Taim, Brasil, RS / Capybaras population structure in the Taim Ecological Station, Brazil, RS

Uma população de capivaras (Hydrochoerus hydrochaeris) foi monitorada na região limítrofe entre a Estação Ecológica do Taim e áreas de cultivo de arroz no extremo sul do Rio Grande do Sul, Brasil. O objetivo foi caracterizar a estrutura populacional, a densidade e os períodos reprodutivos da capivara na Estação Ecológica do Taim, RS, e em seu entorno. De agosto de 2003 a agosto de 2005, foram realizados 25 censos de contagem direta, em um transecto de 4.000 metros de comprimento, às margens da Lagoa Mangueira. Foi obtida a abundância de animais segundo seu sexo e classe etária. A abundância foi de 608,6±27,9 indivíduos e a densidade média foi de 5,1±0,2ind. ha-1. Houve variação no número de animais do primeiro para o segundo ano de amostragem, sendo significativamente maior no último. Foram identificados, em média, 22,0±0,8 grupos na área, constituídos predominantemente de fêmeas adultas (47,5 por cento), seguidas de juvenis (24,8 por cento), filhotes (17 por cento) e machos adultos (7,7 por cento). A abundância de animais variou segundo a distribuição espacial, sendo maior no interior da Estação Ecológica do Taim (9,5ind. ha-1). Houve flutuações sazonais no recrutamento da população, tendo suas maiores densidades de filhotes no outono.

A capybara population (Hydrochoerus hydrochaeris) was monitored in a borderline region between Taim Ecological Station and southernmost areas of rice cultivation located in the State of Rio Grande do Sul (RS, Brazil). The aim of this study was to characterize the structure, density, and reproductive periods of this population. A total of 25 censuses, obtained through direct count technique, were performed from August 2003 to August 2005. The samplings were performed in a 4000-meter length transect on the margins of Mangueira lagoon. The abundance was obtained considering the sex and age class of the animals. The abundance registered was of 608.6±27.9 individuals, and the average density was 5.1±0.2ind. ha-1. A variation in number of animals was observed between the first and the second year of sampling. This number was significantly higher in the last year. An average of 22.0±0.8 groups was identified in the sampling area, including female adults (47.5 percent), juveniles (24.8 percent), young (17 percent) and male adults (7.7 percent). The abundance of animals varied according to spatial distribution, and its highest value (9.5ind. ha-1) was registered in Taim Ecological Station. Seasonal fluctuations in the population recruitment were also observed during this study. The highest densities of young were registered in autumn. Population structure was similar to those registered in different areas of distribution, but it has presented a high potential of population growth.

Ecologia reprodutiva de Hydromedusa tecifera (Testudines: Chelidae) no sul do Brasil / Reproductive ecology of Hydromedusa tectifera (Testudines: Chelidae) in southern Brazil

Existem poucos dados na literatura sobre a reprodução de Hydromedusa tectifera (Chelidae), e estes se referem a indivíduos de cativeiro. A ecologia reprodutiva da espécie foi verificada através de monitoramentos não sistemáticos entre 1996 e 2002 na Estação Ecológica do Taim, no extremo sul do Brasil, com a intenção de reunir informações sobre a reprodução da espécie em ambiente natural. Foram encontrados 46 ninhos da espécie, entre intactos e predados. As ninhadas tiveram, em média, 11,6 ovos que apresentaram um tamanho médio de 36,5 x 23,9 mm. A média do peso dos ovos foi de 11,1 g e o seu volume individual resultou em uma média de 10148,31 mm³. Os ninhos alcançaram uma profundidade média de 11,1 e 5,8 cm da superfície ao primeiro ovo. A variação do volume dos ovos de um mesmo ninho foi menor (CV = 4,71 por cento) do que entre diferentes ninhos (CV = 12,32 por cento). A largura dos ovos foi positivamente dependente do seu comprimento. Já em uma mesma ninhada, o número de ovos não dependeu do seu tamanho e do seu volume. Foram observadas desovas nos meses de novembro e dezembro, mas a maioria delas ocorreu na segunda quinzena de novembro. A espécie desovou com maior freqüência no período das 18 às 20 horas, e em áreas com certa inclinação do substrato, entre 20º e 30º de declividade. A maior abundância de ninhos foi observada até 5 m de distância da lagoa. Os resultados encontrados demonstram congruência entre os dados obtidos para H. tectifera e aqueles existentes para cágados-de-pescoço-comprido da Austrália e para as espécies de Chelidae do extremo sul do Brasil.

The few available information on the reproductive behavior of Hydromedusa tectifera (Chelidae) are based on captive individuals. The H. tectifera reproductive biology was verified from 1996 to 2002 by non-systematic surveys in the Estação Ecológica do Taim, southern Brazil. Forty-six intact and damaged nests of the species were found. Mean clutch size was 11.6 eggs which exhibited a mean size of 36.5 x 23.9 mm and an average weight of 11.5 g. Individual mean eggs volume resulted an average of 10148.31 mm³. Nests had an average depth of 11.1 and 5.8 cm from the surface to the first egg. The eggs volume variation in the same nest was smaller (CV = 4.71 percent) than among different nests (CV = 12.32 percent). The eggs width was positively dependent of their length. In the same hatch the number of eggs did not depended of their size or volume. Nesting behavior was observed in November and December. The species showed higher frequency for nesting between 6 and 8 p.m., in areas with certain inclination of the substratum, between 20º and 30º of declivity. Higher nest abundance was verified up to 5 m from the lagoon. The results show that the data obtained for H. tectifera are similar to those previously reported for Australian snake-necked turtles and for species of Chelidae from southern Brazil.

Macroinvertebrados bentônicos como indicadores de qualidade de água na Barragem Santa Bárbara, Pelotas, RS, Brasil / Zoobenthics as indicators of the water quality in the Santa Bárbara Dam, Pelotas, RS, Brazil

O objetivo deste trabalho foi estudar o impacto de dois afluentes da barragem Santa Bárbara sobre o ambiente da mesma, utilizando a ocorrência de invertebrados bentônicos e características químicas da água. Durante nove meses foram realizadas coletas e análises da água e de invertebrados bentônicos nos afluentes Sanga da Barbuda e Sanga do Passo do Cunha e também no interior da bacia de acumulação da barragem. Os resultados mostram que, embora a Sanga da Barbuda e a Sanga do Passo do Cunha apresentem características químicas abaixo do recomendável, no limite aceitável pela legislação que determina os padrões de qualidade da água para abastecimento público, estes afluentes estão, ainda, sendo diluídos de forma satisfatória na bacia de acumulação da barragem. O estudo das relações entre variáveis químicas e invertebrados bentônicos mostra haver correlação significativa entre os baixos níveis de oxigênio dissolvido e a presença de Oligochaeta, sendo que o aumento do número de Oligochaeta indica uma situação de anoxia na barragem Santa Bárbara.