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Mammals can show conspicuous behavioral responses to thermal variation, including changes in movement patterns. We used an integrative approach to understand how environmental temperature can drive the movement behavior of a mammal with low capacity for physiological thermoregulation, the giant anteater (Myrmecophaga tridactyla). We tracked 52 giant anteaters in 7 areas throughout the Brazilian savannah. We estimated the distance moved, area used, use of forest areas, and mean environmental temperature for each monitoring day of each individual. We modeled these data with Mixed Structural Equations - considering the possible interactions between our variables and controlling for sex and body mass. Giant anteaters reduced displacement and increased forest use with decreasing environmental temperature, probably because of their low body heat production. It is possible that they reduce distance moved and area used by reducing the duration of activity. With decreasing temperature, forest habitats become warmer than open ones, besides buffer rain and chilly winds. Reducing displacement and using forests are important strategies to reduce body heat loss and the energetic costs of thermoregulation. However, decreasing movement can limit food access and, consequently, fitness. Therefore, we highlight the importance of forests as thermal shelters. With increasing frequency and intensity of extreme weather events, we showed the need to preserve forest patches to offer suitable conditions for tropical mammals' behavioral thermoregulation. In this context, policies favoring deforestation on Brazilian territory are especially worrisome. Finally, we emphasize the need of integrative approaches to understand the complex interactions between organisms and the environment.
Assuntos
Ecossistema , Vermilingua , Animais , Regulação da Temperatura Corporal , Florestas , Mamíferos , TemperaturaRESUMO
Habitat loss is the main threat to biodiversity conservation worldwide. Some species may be particularly susceptible to the effects of fragmentation and the isolation of populations. The impacts of human activity on wild animal populations may be understood through relationships between individual genetic data and spatial landscape variables, particularly when considering local population dynamics influenced by fragmented habitats. Thus, the objective of this study was to analyze the population structure and genetic diversity of the giant anteater (Myrmecophaga tridactyla) using an individual sampling scheme (ISS) on a regional geographic scale. Data were collected from 41 specimens from twenty different locations in São Paulo State, Brazil, and six polymorphic microsatellite loci were genotyped. Our results indicate that barriers to gene flow exist and have segregated individuals of the farther away areas into two spatially structured clusters. The populations were also found to have high genetic diversity. The experimental sampling approach used herein enabled an analysis of the population dynamics of the giant anteater on a regional scale, as well as the identification of priority populations for genetic resource conservation for this species. The results reflect the need for adequate management plans. The efficacy of the sampling scheme may vary based on the study model used, but we argue that the use of an ISS combined with suitable molecular markers and statistical methods may serve as an important tool for initial analyses of threatened or vulnerable species, particularly in anthropized regions where populations are small or hard to characterize.
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Spatial ecology data are essential for conservation purposes, especially when extinction risk is influenced by anthropogenic actions. Space use can reveal how individuals use the habitat, how they organize in space, and which components are key resources for the species.We evaluated the space use and multiscale habitat selection of giant anteaters (Myrmecophaga tridactyla), a vulnerable Neotropical mammal, in a Cerrado site within a human-modified landscape in southeastern Brazil.We used GPS transmitters to track eight anteaters in the wild. With the resulting dataset, we estimated home range and core-area sizes and then used two overlap indexes. We assessed habitat selection by compositional analysis and analyzed events of spatio-temporal proximity.The average Brownian bridge kernel estimate of home range size was 3.41 km2 (0.92-7.9). Regarding home range establishment, five individuals showed resident behavior. Males (n = 4) had larger home ranges and were more active than females (n = 4). Despite the spatial overlap of home range (above 40% in four dyads), maximum temporal space sharing was 18%. Giant anteaters were found in proximity. Habitat selection favored savanna, and exotic timber plantation was always avoided. Roads and built-up areas were selected secondarily at the landscape level.The selection of anthropogenic sites denotes behavioral plasticity regarding modified habitats. However, the high selectivity for savanna, at all levels, demonstrates a high dependence on natural habitats, which provide the necessary resources for the species. The recurrent proximity of male-to-female anteaters may indicate reproductive behavior, which is essential for maintaining this isolated population.
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INTRODUCTION: Pachysentis comprises 10 species, which have been reported parasitizing mammals in Africa and the American continent. However, species of Pachysentis have not been described in brow-nosed coatis. Pachysentis lauroi n. sp. (Oligacanthorhynchidae: Acanthocephala) is described from the brown-nosed coati Nasua nasua (Linnaeus, 1766) Storr, 1780 (Procyonidae: Carnivora) in the Brazilian Pantanal wetlands of the Mato Grosso do Sul State, Brazil. METHODS: Specimens were studied using light and scanning electron microscopy. RESULT: The new species is distinguished from other species of Pachysentis by the number of hooks in each longitudinal row (12 rows of 4 hooks, total of 48 hooks), presence of barbs on all hooks, and the organization of the cement glands. Notes on the genus Pachysentis [14] and a key to its species are provided. Critical comments on some species with a dubious diagnosis and questionable or missed key taxonomic characteristics are also reviewed. We also discuss the zoogeography of the members of the genus.
Assuntos
Acantocéfalos/isolamento & purificação , Helmintíase Animal/parasitologia , Procyonidae/parasitologia , Acantocéfalos/classificação , Acantocéfalos/genética , Acantocéfalos/crescimento & desenvolvimento , Animais , Brasil , Feminino , MasculinoRESUMO
We investigated the home range size, habitat selection, as well as the spatial and activity overlap, of four mid-sized carnivore species in the Central Pantanal, Mato Grosso do Sul, Brazil. From December 2005 to September 2008, seven crab-eating foxes Cerdocyon thous, seven brown-nosed coatis Nasua nasua, and six ocelots Leopardus pardalis were radio-collared and monitored. Camera trap data on these species were also collected for the crab-eating raccoon Procyon cancrivorus. We hypothesized that there would be large niche differentiation in preferred habitat-type or active period between generalist species with similar diet, and higher similarity in habitat-type or activity time between the generalist species (crab-eating foxes and coatis) and the more specialized ocelot. Individual home ranges were estimated using the utilization distribution index (UD- 95% fixed Kernel). With data obtained from radio-collared individuals, we evaluated habitat selection using compositional analysis. Median home range size of ocelots was 8 km2. The proportion of habitats within the home ranges of ocelots did not differ from the overall habitat proportion in the study area, but ocelots preferentially used forest within their home range. The median home range size of crab-eating foxes was 1.4 km2. Foxes showed second-order habitat selection and selected savanna over shrub-savanna vegetation. The median home range size for coati was 1.5 km2. Coati home ranges were located randomly in the study area. However, within their home range, coatis occurred more frequently in savanna than in other vegetation types. Among the four species, the overlap in activity period was the highest (87%) between ocelots and raccoons, with the least overlap occurring between the ocelot and coati (25%). We suggest that temporal segregation of carnivores was more important than spatial segregation, notably between the generalist coati, crab-eating fox and crab-eating raccoon.
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Wild animals are infected by diverse parasites, but how they influence host health is poorly understood. We examined the relationship of trypanosomatids and gastrointestinal parasites with health of wild brown-nosed coatis (Nasua nasua) from the Brazilian Pantanal. We used coati body condition and hematological parameters as response variables in linear models that were compared using an information theoretic approach. Predictors were high/low parasitemias by Trypanosoma cruzi and T. evansi, and indices representing the abundance of distinct groups of gastrointestinal parasites. We also analyzed how host health changed with host sex and reproductive seasonality. Hemoparasites was best related to coati body condition and hematological indices, whereas abundance of gastrointestinal parasites was relatively less associated with coati health. Additionally, some associations were best predicted by models that incorporated reproductive seasonality and host sex. Overall, we observed a lower health condition during the breeding season, when coatis are under reproductive stress and may be less able to handle infection. In addition, females seem to handle infection better than males. Body condition was lower in coatis with high parasitemias of T. evansi, especially during the reproductive season. Total red blood cell counts, packed cell volume, platelets and eosinophils were also lower in animals with high T. evansi parasitemias. Total white blood cell counts and mature neutrophils were lower in animals with high parasitemias for both Trypanosoma species, with neutrophils decreasing mainly during the reproductive season. Overall, decreases in hematological parameters of females with T. evansi high parasitemias were less evident. For T. cruzi, monocytes decreased in individuals with high parasitemias. High abundances of microfilariae in the bloodstream, and cestode eggs and coccidian oocysts in feces were also associated with coati blood parameters. This study shows the potential value of examining hematological parameters as an approach to better understand the ecological relevance of parasite-host interactions.
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Doença de Chagas/veterinária , Coinfecção/parasitologia , Trato Gastrointestinal/parasitologia , Enteropatias Parasitárias/veterinária , Procyonidae/parasitologia , Animais , Animais Selvagens/parasitologia , Brasil , Doença de Chagas/parasitologia , Reservatórios de Doenças/parasitologia , Eritrócitos/parasitologia , Fezes/parasitologia , Feminino , Interações Hospedeiro-Parasita , Enteropatias Parasitárias/parasitologia , Contagem de Leucócitos , Leucócitos/imunologia , Masculino , Microfilárias/crescimento & desenvolvimento , Neutrófilos/imunologia , Parasitemia/parasitologia , Fatores Sexuais , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
Abstract The Bare-faced Curassow Crax fasciolata (Cracidae:Cracinae) is a vulnerable species that was classified as critically endangered by the São Paulo State -Brazil, in 2008. Specialists recommended "searches for areas where there may be a few remaining populations and protection of the last remaining semideciduous forest in the State". Protected areas were investigated in the Cerrado and semideciduous forest in São Paulo State by camera trapping to evaluate the presence of the Bare-faced Curassow. Eight protected areas in Cerrado biome were investigated, but the Bare-faced Curassows was recorded only at Furnas do Bom Jesus State Park (2,069 ha), São Paulo State despite the large sampling effort in larger protected areas such as the Santa Bárbara Ecological Station (2,712 ha) and Jataí Ecological Station (9,074 ha); the largest protected area of Cerrado biome in São Paulo State. This record of C. fasciolata is important for the Conservation Action Plan for the Cracid family and shows the importance of monitoring biodiversity and conserving even relatively small remnants of native vegetation for the conservation of this species.
Resumo O mutum-de-penacho Crax fasciolata (Cracidae:Cracinae) é uma espécie ameaçada de extinção e foi considerada criticamente em perigo em 2008 no estado de São Paulo. As recomendações dos especialistas para a conservação da espécie no estado foram "a pesquisa por áreas onde poderia existir populações remanescentes e a proteção de remanescentes de floresta semidecidual". Neste trabalho, oito Unidades de Conservação foram investigadas em áreas com vegetação de Cerrado e de floresta semidecidual por meio de armadilhas fotográficas digitais para verificar a presença do mutum-de-penacho (Crax fasciolata). Entretanto, o mutum-de-penacho foi registrado apenas no Parque Estadual Furnas do Bom Jesus, que possui 2.069 ha, apesar do maior esforço amostral em áreas maiores, como a Estação Ecológica de Santa Bárbara (2.712 ha) e Estação Ecológica de Jataí (9.074),- a maior Unidade de Conservação do bioma Cerrado no estado de São Paulo. O registro do mutum-de-penacho no Parque Estadual Furnas do Bom Jesus é muito importante para o Plano de Ação e Conservação da família Cracidae e mostra a importância do monitoramento da biodiversidade e a conservação de remanescentes de vegetação nativa, mesmo pequenos, para a conservação dessa espécie.
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This is a long-term follow-up of infection by Trypanosoma cruzi (TC) and Trypanosoma evansi (TE) in the free-ranging coatis (Procyonidae: Nasua nasua) from Pantanal region (Mato Grosso do Sul, Brazil). We evaluated TC and TE infection by immunofluorescence assay, hemoculture (HC), and microhematocrit centrifuge techniques (MHCT). We also examined coatis health by quantifying hematological parameters including packed cell volume (PCV), white blood cell (WBC) count, and differential leukocyte count. TC isolates thought HC were typed by miniexon gene. Mixed infections by both parasites and the two main lineages of TC (76% TCI, 3% TCII, and 14% TCI/TCII) were observed. Trypanosoma rangeli was also isolated (7%). Overall, seroprevalence of TC and TE infection were 53.5% and 42.0%, respectively. Positive HC (indicating high TC parasitemia) occurred in 34% of seropositive coatis for TC, and positive MHCT (high TE parasitemia) were observed in 36.4% of seropositive coatis for TE. We detected higher prevalence of positive HC in females (72%) than males (43%), and also during the dry season, indicating a seasonal potential of this host species on TC transmission. These features did not occur for TE infection. However, prevalence of TE based on serology and MHCT was higher among adults than subadults. Coatis with positive HC or MHCT displayed a slight decrease in their WBC. In contrast to the animals with positive HC, coatis with positive MHCT displayed a decrease on their PCV. Moreover, concurrent high TC and TE parasitemia caused a larger decrease of PCV values. This study corroborates the importance of coatis in the maintenance of TC and TE transmission cycles in the southern Pantanal and shows a seasonal character of TC transmissibility to its vector by the coati population from the study area.
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Procyonidae/sangue , Procyonidae/parasitologia , Tripanossomíase/sangue , Tripanossomíase/epidemiologia , Animais , Antígenos de Protozoários , Brasil/epidemiologia , Reservatórios de Doenças/parasitologia , Feminino , Imunofluorescência , Raposas/parasitologia , Estudos Longitudinais , Masculino , Fatores de Risco , Estações do Ano , Trypanosoma/imunologia , Trypanosoma/isolamento & purificação , Trypanosoma cruziRESUMO
This study demonstrates that ocelots (Leopardus pardalis) extensively use primates as a food resource at the Caratinga Biological Station (CBS) in Southeast Brazil. Analysis of 60 fecal samples collected over 4 years revealed predation upon the brown howler monkey (Alouatta guariba), the muriqui (Brachyteles hypoxanthus), and the brown capuchin monkey (Cebus apella). The most frequent items found in the fecal samples analyzed were Calomys (n=16) and non-identified Aves (n=15), followed by A. guariba (n=12). Although Rodentia was the most common group consumed (n=52) Primates were found in 27% of total fecal samples and were the third most consumed group in relation to the total items. Particularly, predation of A. guariba by ocelots (20% of the total fecal samples) was not an isolated event; our results showed that this species was preyed on across several months. Predation on primates was far higher at CBS than at other sites where comparable studies have been carried out.