Age and habitat quality matters: isotopic variation of two sympatric species of rodents in Neotropical Forest

Dietary studies allow us to understand important ecological patterns such as intra- and interpopulation variation and interspecific differences regarding the use of food sources. Stable isotopes have been successfully employed to detect dietary differences between species and feeding shifts within a species, as a response to age, habitat use, and resource availability. Here we investigated the stable isotope compositions of carbon and nitrogen of young and adult specimens of Euryoryzomys russatus and Sooretamys angouya and their stomach contents, in a complex mosaic of vegetation in the Brazilian Atlantic Forest. Isotopes indicated a pronounced inter- and intraspecific plasticity in resource use for E. russatus and S. angouya. Plant sources were the prevalent feeding items for E. russatus, with low to intermediate consumption of arthropods. For S. angouya, plants were dominant in the stomach content, but arthropod arose as an important source. E. russatus showed more variation in isotopic signature between grids than S. angouya, suggesting that the former was more affected by habitat changes. These results allow us to better understand the ontogeny, diet and the behavioral responses to environmental variations of both species. Finally, our study contributes to reduce the lack of knowledge about sympatric species ecology and aggregates information for their conservation.Fil: Bovendorp, Ricardo Siqueira. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil. Universidade Estadual Paulista “Júlio de Mesquita Filho”; BrasilFil: Simoes Libardi, Gustavo. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Sarmento, Mariana Montagner de Moraes. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Camargo, Plínio Barbosa. Universidade de Sao Paulo; BrasilFil: Reis Percequillo, Alexandre. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasi

Spatiotemporal Dynamics of Hantavirus Cardiopulmonary Syndrome Transmission Risk in Brazil

Background: Hantavirus disease in humans is rare but frequently lethal in the Neotropics. Several abundant and widely distributed Sigmodontinae rodents are the primary hosts of Orthohantavirus and, in combination with other factors, these rodents can shape hantavirus disease. Here, we assessed the influence of host diversity, climate, social vulnerability and land use change on the risk of hantavirus disease in Brazil over 24 years. Methods: Landscape variables (native forest, forestry, sugarcane, maize and pasture), climate (temperature and precipitation), and host biodiversity (derived through niche models) were used in spatiotemporal models, using the 5570 Brazilian municipalities as units of analysis. Results: Amounts of native forest and sugarcane, combined with temperature, were the most important factors influencing the increase of disease risk. Population at risk (rural workers) and rodent host diversity also had a positive effect on disease risk. Conclusions: Land use change—especially the conversion of native areas to sugarcane fields—can have a significant impact on hantavirus disease risk, likely by promoting the interaction between the people and the infected rodents. Our results demonstrate the importance of understanding the interactions between landscape change, rodent diversity, and hantavirus disease incidence, and suggest that land use policy should consider disease risk. Meanwhile, our risk map can be used to help allocate preventive measures to avoid disease.publishedVersio

Natural history and ecology for two sympatric Oryzomyini rodents (Cricetidae: Sigmodontinae) in the Atlântic Forest

Dentre os ecossistemas neotropicais, a Mata Atlântica é considerada um dos mais importantes hotspots mundiais. O presente estudo foi conduzido na Reserva Florestal Morro Grande - RFMG (23°39\'-23°48\'S, 47°01\'-46°55\'W), reconhecida pelo seu alto valor para a conservação e está localizada na faixa da Mata Atlântica Ombrófila Densa Montana, Planalto Atlântico do Estado de São Paulo. Presentes na Mata Atlântica, os pequenos mamíferos não-voadores constituem o grupo de mamíferos mais diverso do bioma, e dados recentes relacionados à representatividade ecológica sugerem que os Orizomíneos mais típicos, comuns e abundantes das florestas costeiras e de planalto no estado de São Paulo são Euryoryzomys russatus e Sooretamys angouya. Estes dados ainda indicam que E. russatus e S. angouya, espécies classificadas respectivamente como \"em risco de extinção\" e \"deficiente de dados\" no Estado de São Paulo, respondem diferentemente ao processo de fragmentação, mas não existem informações suficientes disponíveis de história natural e autoecologia para o melhor entendimento destas respostas ao ambiente. O presente projeto avaliou a estrutura populacional, a área de vida, o uso do espaço, a dieta e seleção alimentar exibida por E. russatus e S. angouya na RFMG. O presente trabalho demonstrou que a espécie E. russatus apresenta uma abundância maior do que S. angouya na RFMG e que a temperatura e a disponibilidade de frutos influenciam a variação populacional de E. russatus, enquanto que, para S. angouya, a variação populacional independe dos fatores bióticos (frutos e artrópodes) ou abióticos (temperatura e precipitação) avaliados. Foi verificado uma estratificação vertical no uso do espaço para S. angouya e E. russatus, já que S. angouya apresentou uma locomoção escansorial enquanto E. russatus se apresentou estritamente terrestre. O estudo sugere que a disponibilidade de recursos, o período reprodutivo e o tamanho do indivíduo são os principais fatores que afetam o tamanho de área de vida, o uso do espaço e a locomoção apresentada pelas espécies. Os resultados obtidos pelo estudo da dieta, demonstram de forma conclusiva que E. russatus seleciona alimentos de origem animal, e que S. angouya utiliza muito pouco, ou não utiliza, fontes de origem animal, mas sim fontes vegetais ricas em proteínas e carboidratos, como os frutos. Este estudo possibilitou a compreensão de estratégias de vida adotadas por E. russatus e S. angouya, o que permitiu uma análise comparada da história natural a partir de um contexto evolutivo de organismos que compartilham a mesma escala geográfica e temporal, o que é algo inédito dentro da tribo e da subfamília.The Atlantic Forest is considered one of the most important global hotspot among the neotropical ecosystems. This study was conducted at the Morro Grande Forest Reserve - MGFR (23°39\'-23°48\'S, 47°01\'-46°55\'W), located in the Dense Montana Atlantic forest, Atlantic Plateau of São Paulo, Brazil, which is known by its high conservation value. The non-flying small mammals are the most diverse group of mammals in the Atlantic forest and recent data suggest Euryoryzomys russatus and Sooretamys angouya as the most common and abundant species in coastal forests and highlands in the state of São Paulo. These data also indicate that E. russatus is classified as endangered and S. angouya as data deficient in the state of São Paulo red list, and these species respond differently to the fragmentation process. This project evaluated the population structure, the living area, the use of space, the diet, and food selection displayed by E. russatus and S. angouya in MGFR. This study demonstrated that the species E. russatus features greater abundance than S. angouya in the study area. Thus, the temperature and the availability of fruits influenced the variation of the population of E. russatus, whereas the population variation of S. angouya showed no dependence of assessed biotic (fruits and arthropods) or abiotic factors (temperature and precipitation). Vertical stratification was observed in the use of space between S. angouya and E. russatus, once S. angouya presented escansorial locomotion and E. russatus was strictly terrestrial. The study suggests that the availability of resources, the reproductive period and the individual overall size are the main factors that affect the home range size, the use of space and mobility presented by the species. The results obtained by the study of diet demonstrate conclusively that E. russatus selects animal origin and S. angouya uses very little or does not use animal food resources, choosing plant sources rich in protein and carbohydrates, such as fruits. This study brought a better understanding of the life strategies adopted by E. russatus and S. angouya, which allowed the comparison of natural history of organisms that share the same spatial and temporal scale under an evolutionary perspective, which is a completely new approach within the tribe and subfamily

Density and population size of mammals introduced on a land-bridge island in southeastern Brazil

The introduction of alien species is one of the main threats to the conservation of native species, especially in island ecosystems. Here, we report on the population growth of 15 species of mammals introduced in 1983 on the island of Anchieta, an 828 ha land-bridge island in southeastern Brazil. We estimated the density of mammals through 296 km of line transect census. Five species introduced became extinct (coypu, brocket deer, six-banded armadillo, nine-banded armadillo, maned three-toed sloth); six became over-abundant (marmoset, coati, agouti, seven-banded armadillo, and capybara); one has a stable population (capuchin monkey). Anchieta Island has the highest density of mammals in the entire Atlantic forest (486.77 ind/km(2)), especially nest predators (232.83 ind/km(2)) and herbivores (253.58 ind/km(2)). Agoutis (Dasyprocta spp.) and marmosets (Callithrix penicillata) were, by far, the species with the highest population growth. The high density of mammals in this island may have strong consequences for plant recruitment and bird diversity

Phenotypic changes and small mammal impoverishment on a Brazilian Atlantic Forest Island

Faunal impoverishment and distorted species compositions are common phenomena in oceanic islands; however, many land-bridge islands are poorly inventoried, especially in the Neotropics. We sampled a small mammal community on a land-bridge island (Anchieta Island) along the Brazilian coast. We found only one marsupial Didelphis aurita (Wied-Neuwied, 1826) and two rodent species Oligoryzomys nigripes (Olfers, 1818) and Trinomys iheringi (Thomas, 1911) during 12 months of live trapping and 9195 trap-nights. The diversity of rodents and marsupials was not explained by species-area relations, indicating possible past extinctions. The abundance of D. aurita and O. nigripes was approximately three times higher, while the abundance of T. iheringi was approximately four times lower than abundances reported from other Brazilian Atlantic Forest sites. The population of D. aurita exhibited many phenotypic changes; males were on average 8 % smaller and females produced 30 % less litters than those from the mainland and other land-bridge islands. The long history of forest disturbance, habitat loss, reduction in forest productivity, and the recent introduction of mesopredators may be the major drivers that explain the small mammal community composition on this island. © 2013 Walter de Gruyter GmbH, Berlin/Boston

Heavy metals in hair of small mammals from the cacao agroforestry and Brazilian Atlantic Forest

The current growing demand for resources, food production, and agricultural crops leads to a drastic reduction in biodiversity and ecosystem services. One of the options to mitigate the recurring effects of land use changes is the adoption of wildlife-friendly systems, such as cacao agroforestry systems, which integrates production with biodiversity conservation. Cacao management involves the frequent use of pesticides, such pesticides are comprised of heavy metals that are considered non-point sources of pollution. Animal hair is considered an excellent cumulative bioindicator of contamination. Small mammals are known as bioindicators of pollution, as they provide a warning of adverse effects on ecosystems. The main objective was to determine the concentrations of six heavy metals (Pb, Ni, Cr, Cd, Mn, and Cu) in hair of small mammals in traditional cacao agroforests and Atlantic Forest fragments in the southern region of Bahia, Brazil. The study covered 12 traditional cacao agroforests and 12 Atlantic Forest fragments. A total of 34 small mammals were captured in the traditional cacao agroforests, representing 12 species, while 18 were captured in the Atlantic Forest fragments, representing 6 species. We found that small mammals in both habitats had similar levels of lead in their hair. Heavy metals concentrations in the hair of small mammals were higher in individuals from traditional cacao agroforests than the Atlantic Forest fragments (Cacao agroforest (mg/Kg): Pb - 26.42 ± 16.42; Ni - 5.31 ± 4.3; Mn - 1.64 ± 2.63; Cu - 1.13 ± 1.15; Cd - 1.42; Atlantic Forest (mg/Kg): Pb - 19.28 ± 14.46; Ni - 0.18; Mn - 0.34 ± 0.40; Cu - 1 ± 2.05). Marsupials exhibited higher lead concentrations compared to rodents (Didelphimorphia (mg/Kg): Pb - 28.66 ± 18.73; Rodentia (mg/Kg): Pb - 18.44 ± 9.85), likely due to their distinct eating habits and habitat use. Body condition of the small mammals did not differ between the two habitat types, and there was no relationship between the bioaccumulation of heavy metals in small mammals and body condition. This is the first study to evaluate heavy metal contamination in small mammals in traditional cacao agroforests and Atlantic Forest fragments, thus providing important data that indicate the presence of heavy metals in the hair of the small mammals sampled, and consequently, the presence of these heavy metals in the environment where these small mammals lived

Professor Júlio Ernesto Baumgarten: (1965 – 2022)

This is an obituary for Professor Júlio Ernesto Baumgarten

Hantavirus host assemblages and human disease in the Atlantic Forest.

Several viruses from the genus Orthohantavirus are known to cause lethal disease in humans. Sigmodontinae rodents are the main hosts responsible for hantavirus transmission in the tropical forests, savannas, and wetlands of South America. These rodents can shed different hantaviruses, such as the lethal and emerging Araraquara orthohantavirus. Factors that drive variation in host populations may influence hantavirus transmission dynamics within and between populations. Landscape structure, and particularly areas with a predominance of agricultural land and forest remnants, is expected to influence the proportion of hantavirus rodent hosts in the Atlantic Forest rodent community. Here, we tested this using 283 Atlantic Forest rodent capture records and geographically weighted models that allow us to test if predictors vary spatially. We also assessed the correspondence between proportions of hantavirus hosts in rodent communities and a human vulnerability to hantavirus infection index across the entire Atlantic Forest biome. We found that hantavirus host proportions were more positively influenced by landscape diversity than by a particular habitat or agricultural matrix type. Local small mammal diversity also positively influenced known pathogenic hantavirus host proportions, indicating that a plasticity to habitat quality may be more important for these hosts than competition with native forest dwelling species. We found a consistent positive effect of sugarcane and tree plantation on the proportion of rodent hosts, whereas defaunation intensity did not correlate with the proportion of hosts of potentially pathogenic hantavirus genotypes in the community, indicating that non-defaunated areas can also be hotspots for hantavirus disease outbreaks. The spatial match between host hotspots and human disease vulnerability was 17%, while coldspots matched 20%. Overall, we discovered strong spatial and land use change influences on hantavirus hosts at the landscape level across the Atlantic Forest. Our findings suggest disease surveillance must be reinforced in the southern and southeastern regions of the biome where the highest predicted hantavirus host proportion and levels of vulnerability spatially match. Importantly, our analyses suggest there may be more complex rodent community dynamics and interactions with human disease than currently hypothesized

Roedores sigmodontíneos da Amazônia brasileira: composição, distribução geográfica e diagnoses

A subfamília Sigmodontinae Wagner, 1843, atualmente alocada na família Cricetidae Fischer, 1817, é o segundo grupo mais diverso dentro dos mamíferos. Esta subfamília é superada em riqueza de espécies apenas pela irradiação de muróideos asiáticos da família Muridae (Musser & Carleton, 2005). Os sigmodontíneos estão amplamente distribuídos nas Américas do Sul e Central e de forma periférica na América do Norte, alcançando o sudeste dos Estados Unidos. Esta subfamília reúne 86 gêneros e 384 espécies apenas na América do Sul, e em toda a sua área de distribuição devem ocorrer aproximadamente 95 gêneros e mais de 400 espécies (D’Elía & Pardiñas, no prelo). Essa alta diversidade está dividida em nove grupos supra-genéricos, alocados na categoria de tribo: Abrotrichini, Akodontini, Ichthyomyini, Oryzomyini, Phyllotini, Reithrodontini, Sigmodontini, Thomasomyini, Wiedomyini, além de alguns gêneros não alocados em nenhuma das tribos. Os agrupamentos mais diversos são as tribos Oryzomyini e Akodontini, que reúnem aproximadamente metade das espécies da subfamília.Fil: Reis Percequillo, Alexandre. No especifíca;Fil: de Abreu Júnior, Edson. Universidade de Sao Paulo; BrasilFil: Bovendorp, Ricardo Siqueira. Universidade Estadual de Santa Cruz; BrasilFil: Brennand, Pamella Gusmão de Góes. Escola Superior de Agricultura "Luiz de Queiroz"; BrasilFil: Chiquito, Elisandra de Almeida. Instituto Nacional da Mata Atlântica; BrasilFil: Correa, Lidiani Silva. No especifíca;Fil: Perez Godoy, Leandro. No especifíca;Fil: Simoes Libardi, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Prado, Joyce Rodrigues Do. Universidade de Sao Paulo; BrasilFil: Roth, Paulo Ricardo de Oliveira. Universidade de Sao Paulo; BrasilFil: Lucena Salles, Vanessa. No especifíca