Amazonian freshwater habitats experiencing environmental and socieconomic threats affecting subsistence fisheries

ALHO, C.J.R.; REIS, R.E.; AQUINO, P.P.U. 2015. Amazonian freshwater habitats experiencing environmental and socieconomic threats affecting subsistence fisheries. AMBIO 44(5):412-425. doi: 10.1007/s13280-014-0610-z

Abstract. Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon’s aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study’s objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.

Are otters generalists or do they prefer large, slower prey? Feeding flexibility of the Neotropical otter Lontra longicaudis in the Atlantic Forest

RHEINGANTZ, M.L.; OLIVEIRA-SANTOS, L.G.; WALDEMARIN, H.F.; CARAMASCHI, E.P. 2012. Are otters generalists or do they prefer large, slower prey? Feeding flexibility of the Neotropical otter Lontra longicaudis in the Atlantic Forest. IUCN Otter Specialist Group Bulletin 29(2):80-94.

Abstract. Despite there being several studies focusing on feeding habits of Lontra longicaudis, few studies aimed to evaluate its prey selectivity and none of them considered prey mobility. In this study, we report both its feeding flexibility and specialist feeding behaviour between two parts of Mambucaba River, Southeastern Brazil. We observed that they fed mainly on fish, crabs and crayfish. We did not observe seasonality either in diet or prey community availability. However, using ANOVA, we found differences between stretches for diet composition and in the availability of prey. Monotonic Multi-Dimensional Scaling ordination showed that the otter diet in mangroves was dominated by Brachyura and the prey availability by Brachyura, Caridea, Ariidae, Mugilidae, Gerreidae, Centropomidae and Cichlidae, while the diet in the river stretch was dominated by Cichlidae, Caridea and Heptapteridae, and the prey availability by Characidae, Erythrinidae and Heptapteridae. According to Ivlev Electivity Index, along the river few preys were consumed according to their abundance, the majority being selected. Otters preferred slower prey, no matter their size. We observed variation in the level of preference of the same prey in different stretches, with flexibility in otter diet. Otter ate few preys according to their abundance, but showed specialist feeding behaviour, eating the slowest prey of the stretch.

On the presence of Holochilus brasiliensis (Desmarest, 1819) (Rodentia: Cricetidae: Sigmodontinae) in the late Pleistocene of southern Brazil

KERBER, L.; LOPES, R.P.; OLIVEIRA, E.V.; RIBEIRO, A.M.; PEREIRA, J. 2012. On the presence of Holochilus brasiliensis (Desmarest, 1819) (Rodentia: Cricetidae: Sigmodontinae) in the late Pleistocene of southern Brazil. GAEA, Journal of Geoscience 8(2):47-54. doi: 10.4013/gaea.2012.82.02.

Abstract. Fossil remains of the sigmodontine rodent Holochilus brasiliensis (Desmarest, 1819) from two geographic areas from the state of Rio Grande do Sul, southern Brazil are reviewed and described here. The specimens came from two localities: Quaraí River in the western region, which has yielded a dentary with an incisor and molars, and Chuí Creek in the eastern region, where a fragmented right dentary and a maxillary fragment with molars were collected. The presence of this taxon in the late Pleistocene of meridional Brazil suggests the existence of perennial water bodies.

Incidental catch of South American sea lion in a pair trawl off southern Brazil

MACHADO, R.; OLIVEIRA, L.R.; MONTEALEGRE-QUIJANO, S. 2015. Incidental catch of South American sea lion in a pair trawl off southern Brazil. Neotropical Biology and Conservation 10(1):43-47. doi: 10.4013/nbc.2015.101.06

Abstract. The population of the South American sea lion, Otaria flavescens (Shaw, 1800), in Uruguay is declining at an annual rate of 1.6 to 2.0%. Although the reasons are still unknown, interactions with fishing activities have been identified as a major cause. The individuals that arrive along the coast of Brazil come from the breeding colonies off Uruguay after their breeding period. We report here the first record of incidental catch of South American sea lions in Brazilian waters by a pair trawl. On July 17th, 2008 a young male of South American sea lion was incidentally caught during a commercial pair trawl fishing trip along the southern Brazilian coast (32º57’S, 52º31’W), in a depth ranging from 15 to 20 m. Despite being punctual, this record is an evidence of a potential major threat to South American sea lions in southern Brazil and Uruguay, since trawl industrial fishing is a very important economic activity in South Brazil.

Use of carbon and nitrogen stable isotopes to study the feering ecology of small coastal cetacean populations in southern Brazil

HARDT, F.A.S.; CREMER, M.J.; JUNIOR, A.J.T.; BELLANTE, A.; BUFFA, G.; BUSCAINO, G.; MAZZOLA, S.; BARRETO, A.S.; MARTINELLI, L.A.; ZUPPI, G.M. 2013. Use of carbon and nitrogen stable isotopes to study the feering ecology of small coastal cetacean populations in southern Brazil. Biota Neotropica 13(4):90-98.

Abstract: Samples from individuals of the populations of Sotalia guianensis (Guiana) and Pontoporia blainvillei (Franciscana) dolphins living in the Babitonga Bay estuary (26° 28’ S/48° 50’ W), and samples from individuals of a second population of P. blainvillei from a nearshore area (26° 38’ S/48° 41’ W), were collected and analyzed along with their prey between 2000 and 2006, to determine the carbon and nitrogen stable isotope ratios and to verify differences in their feeding ecology. No differences were found in the median ð15N values of Guiana (15.2‰) and Franciscana (15.9‰) dolphins living in Babitonga Bay, nor of nearshore Franciscana (15.0‰) individuals, suggesting no variation in the trophic level of these populations. However, the lack of more information on the isotopic compositions of their putative prey in the nearshore areas prevents the ability to draw definitive conclusions on this issue. The estuarine Franciscana and Guiana dolphin populations presented mean ð13C values of approximately –15.7‰, which were not statistically different from nearshore Franciscana individuals (–14.8‰). Based on stomach content analyses of these species from a previous study, it was reported that there was little overlap in the diet of estuarine Franciscanas and Guiana dolphins. However, based on the similarity of the ð13C values between these two species and of their putative prey, it appears that in fact there is an overlap in the diet of these two species. Based solely on stable isotope analysis, it was not possible to differentiate between estuarine and nearshore Franciscana populations, making it difficult to conclude whether captured nearshore specimens were indeed yearlong residents of these areas. Finally, this study suggests that Franciscana and Guiana dolphin populations are sharing the same resources, mostly L. brevis, D. rhombeus, and S. rastrifer. Therefore, the combination of resource sharing and commercial exploitation of their prey makes these two cetacean species vulnerable.

Journals: Marine Mammal Science

Marine Mammal Science

- Abreviatura: Mar. Mammal Sci.

- Home Page: http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-7692

- Qualis CAPES: A2 (Biodiversidade), B2 (Ciências Biológicas I).

- Taxa de Publicação: Não há.

- Idiomas: Inglês.

- Disponibilidade: Restrito. Apenas os artigos do fascículo mais recente estão disponíveis na home page.

- Submissão: Online, pelo sistema ScholarOne, com acesso na home page da revista.

O periódico Marine Mammal Science publica significativos novos achados em mamíferos marinhos resultantes de pesquisas originais em sua forma e função, evolução, sistemática, fisiologia, bioquímica, comportamento, biologia populacional, história de vida, genética, ecologia e conservação. Extensão de distribuição, observações incomuns de comportamento, e estudos preliminares de poucos indivíduos são publicados apenas quando há informação nova suficiente para tornar o manuscrito de interesse geral. Baixa prioridade será dada a confirmação de investigações de interesse local ou regional.

O periódico endossa o princípio de que experimentos utilizando animais vivos devem ser empreendidos apenas para propósitos de avanço do conhecimento. Considerações devem ser dadas aos procedimentos experimentais apropriados, espécies animais utilizadas, e número de animais necessários. Todos os experimentos com animais relatados no Marine Mammal Science devem ser conduzidos em conformidade com as regras de cuidado animal relevantes do país de origem. O Editor irá recusar manuscritos cujas evidências de adesão a estas regras não sejam aparentes.

Journals: Latin American Journal of Aquatic Mammals

Latin American Journal of Aquatic Mammals

- Abreviatura: Lat. Am. J. Aquat. Mamm. (LAJAM)

- Home Page: http://lajamjournal.org/index.php/lajam

- Qualis CAPES: B4 (Biodiversidade), C (Ciências Biológicas I e III).

- Taxa de Publicação: Sim. Gratuito para membros do SOLAMAC e SOMEMMA.

- Idiomas: Inglês.

- Disponibilidade: Restrito.

- Submissão: Online, em um sistema próprio, com acesso na home page.

A Latin American Journal of Aquatic Mammals (LAJAM) publica artigos acadêmicos sobre biologia, manejo e conservação de mamíferos aquáticos na América Latina. A LAJAM procura promover e disseminar o conhecimento científico sobre mamíferos aquáticos e seu ambiente na América Latina.

A Latin American Journal of Aquatic Mammals é publicada bianualmente, em junho e dezembro.

Interactions between short-beaked common dolphin (Delphinus delphis) and the winter pelagic pair-trawl fishery off Southwest England (UK)

BOER, M.N.; SAULINO, J.T.; LEOPOLD, M.F.; RIJNDERS, P.J.H.; SIMMONDS, M.P. 2012. Interactions between short-beaked common dolphin (Delphinus delphis) and the winter pelagic pair-trawl fishery off Southwest England (UK). International Journal of Biodiversity and Conservation 4(13):481-499. doi: 10.5897/IJBC12.016

Abstract. During offshore and onshore studies (2004 to 2009), the interactions between pair-trawls and shortbeaked common dolphins (Delphinus delphis) were studied to better understand the impact of bycatch. A ‘hotspot’ area where pair-trawls overlapped with high dolphin abundance was identified. We made comparisons between boat-based data collected in absence and presence of pair-trawlers. The relative abundance and group-size of dolphins was significantly higher in the presence of pair-trawlers. Dolphins were observed associating with towing and hauling procedures. Significantly, more carcasses occurred in areas with hauling-activity than those without. Body-temperatures obtained from carcasses found near operating pair-trawlers indicated that bycatch mostly occurred at night. During necropsy studies, difficulties were encountered in identifying the fishing-gears responsible. Strandings data highlighted that the number of dead stranded dolphins was probably much higher than previously reported and there was a significant difference in the age and gender-composition of carcasses. Mature/sub-adult males appeared at greater risk from entanglement in pair-trawls offshore, whilst females with young appeared more vulnerable to inshore gillnets. Our findings show that the overlap between pelagic fisheries and the common dolphin hotspot is causing direct mortality through bycatch and, together with recent range-shifts, may have contributed to a localised decline of this species in this winter hotspot since 2007.

Biologia e Conservação de Baleias-Franca

Mamíferos: Diversidade, ecologia, métodos de estudo e conservação

O Laboratório de Ecologia de Mamíferos da Unisinos está promovendo o curso Mamíferos: Diversidade, ecologia, métodos de estudo e conservação nos dias 23, 24 e 31 de agosto de 2013, na Unisinos - São Leopoldo/RS. As inscrições estão abertas! Visite www.unisinos.br/eventos para maiores informações.

VII Encontro Nacional sobre Conservação e Pesquisa de Mamíferos Aquáticos

O Laboratório de Ecologia de Mamíferos da Unisinos tem o prazer de convidar todos os profissionais e estudantes das mastozoologia ao VII Encontro Nacional sobre Conservação e Pesquisa de Mamíferos Aquáticos (Encopemaq), que ocorrerá entre os dias 02 e 04 de outubro de 2013 na Universidade do Vale do Rio dos Sinos (UNISINOS), São Leopoldo, RS, Brasil.

Este evento tem como objetivo promover o intercâmbio entre estudantes e profissionais da área de conhecimento dos mamíferos aquáticos como subsídio à pesquisa, ao ensino e à extensão, e discutir iniciativas que visem à conservação deste grupo de animais.

As palestras deste VII Encopemaq terão como tema "os avanços sobre a biologia dos mamíferos aquáticos através das inovações tecnológicas". Neste evento adotamos uma inovação no formato das palestras, o qual seguirá o dos grandes eventos contemporâneos: vários palestrantes com apresentações compactas e sem palestras simultâneas, para que os participantes possam assistir todo o evento, maximizando o aproveitamento deste encontro.

Os interessados poderão submeter resumos até o dia 09 de agosto de 2013. Maiores informações em: http://www.unisinos.br/eventos/encopemaq/

Anomalous color in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora)

ABREU, M.S.L.; MACHADO, R.; BARBIERI, F.; FREITAS, N.S.; OLIVEIRA, L.R. 2013. Anomalous color in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora). Brazilian Journal of Biology 73(1):185-194.

Abstract. Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males  and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are  becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves  primarily through echolocation, and their refuges provide protection against light and predation. It is possible that  anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported.  Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.

Revisão sobre o fenômeno da hibridização em cetáceos e pinípedes

SCHAURICH, M.N.; LOPES, F.R.V.; OLIVEIRA, L.R. 2012. Revisão sobre o fenômeno da hibridização em cetáceos e pinípedes. Neotropical Biology and Conservation 7(3):199-209.

Abstract. The hybridism is the result of mating between two individuals from different and reproductively isolated gene pools accepted as species that usually generate infertile offspring. The evolutionary consequences of this phenomenon vary depending on the mating system, hybrid’s frequency, the degree of reproductive isolation and the genetic differences between the parental species as well as their speciation process. Hybrids have been recorded frequently in aquatic and terrestrial mammals, both in nature and captivity. We review studies published in peer-reviewed journals between 1940 and 2010, in which hybrid cases were reported for cetaceans and pinnipeds. We found 37 scientific papers recording 1,201 hybrids: 57 in cetaceans (nature = 27; captivity = 30) and 1,144 in pinnipeds (nature = 1,137; captivity = 7). A possible explanation for this phenomenon in the wild could be the close phylogenetic relatedness between parental species and also the potential absence of conspecific breeding partners. This last factor could be a result of population decline due to commercial exploitation occurred in the past. This fact is valid for pinnipeds, but especially true for blue whales, Balaenoptera musculus. It is important to note that about 99% of pinniped hybrids were reported in sympatric breeding colonies along the subantarctic islands, which facilitate the hybridization. Outbreeding depression followed by loss of genetic variability and reduction of evolutionary potential and consequently increasing the risk of extinction are the most important results of the hybridism.

Genome-wide loss of diversity in the critically endangered hawaiian monk seal

SCHULTZ, J.K.; MARSHALL, A.J.; PFUNDER, M. 2010. Genome-wide loss of diversity in the critically endangered hawaiian monk seal. Diversity 2(6):863-880. doi: 10.3390/d2060863.

Abstract. Threatened species often exhibit low genetic diversity as a result of selective sweeps, historical bottlenecks, or persistent small population size. Whereas selective sweeps create localized reduction of variation at a chromosome, population bottlenecks result in the loss of rare alleles throughout the genome. Heterozygosity is lost more slowly and is severely impacted only when populations are small for an extended period of time. We test the hypotheses of selective sweep, historical bottleneck and persistently small population size to explain extremely low genetic diversity in the critically endangered Hawaiian monk seal (Monachus schauinslandi). Of 163 microsatellite loci isolated from the species’ genome, only 17 are polymorphic. Mapping 98 monomorphic and 12 polymorphic loci to 35 chromosomes throughout the dog genome, we reject the selective sweep hypothesis. Genotyping 2,423 Hawaiian monk seals at the 17 polymorphic loci plus a locus previously isolated from another pinniped species, we find evidence for a recent bottleneck (P = 0.04). This is consistent with historical records describing intense hunting in the 19th century; however, the bottleneck was not of sufficient severity and duration to explain the genome-wide depletion of genetic diversity (HO = 0.05; A = 1.1). Long-term population size restriction is a more likely explanation. Though at least two of the polymorphic loci appear to be candidates for selection, the low genetic diversity of the species may further threaten chances for survival of this critically endangered species in a changing world.

Feeding of the Neotropical river otter (Lontra longicaudis) in the coastal region of the Rio Grande do Sul State, southern Brazil

COLARES, E.P.; WALDEMARIN, H.F. 2000. Feeding of the Neotropical river otter (Lontra longicaudis) in the coastal region of the Rio Grande do Sul State, southern Brazil. IUCN Otter Spec. Group Bull. 17(1):1-6.

Abstract. In the coastal region of the Rio Grande do Sul State, in southern Brazil, three areas were monitored to study the feeding habits of the neotropical river otter (Lontra longicaudis) using spraint analysis. The National Park of the Peixe Lagoon was monitored seasonally between August 1995 and July 1996, in the Senandes Creek five samplings were done between June and December 1995 and in the Estiva Creek monthly samplings were done between May 1995 and July 1996. In each of these areas spraints were collected and stored. In the laboratory they were washed, separated and identified. The only area where it  was possible to do a seasonal analysis of the feeding habits was the Estiva Creek. In all areas fish was the item found in the great number of spraints and crustaceans also had a considerable importance in areas with salt-water influence. The other items found were  present in few samples, being them mollusks, insect, reptiles, birds and mammals. The differences observed in the feeding habits of the species between seasons and areas probably reflects the availability of different preys, agreeing the species opportunism.

II Curso Teórico-Prático: Biologia e Ações de Conservação de Baleias-Franca

As incrições para o curso teórico-prático Biologia e Ações de Conservação de Baleias-Franca estão abertas. O evento iniciará na sexta-feira, dia 14 de setembro, as 13:30hs e terminará no domingo, dia 16 de setembro ao meio dia, na praia de Garopaba, Santa Catarina.
A saída para observação de baleias ocorrerá no sábado, pelo período da manhã, podendo ser transferida para domingo, dependendo das condições de vento e mar.

As formas de pagamento podem ser feitas através de depósito da quantia total do curso (R$320,00) ou em duas vezes, uma de 50% (R$160,00) por depósito e o restante na data de início do curso.
*
Conta para o depósito:*
*Banco do Brasil*
Agência: 5311-2
Conta Poupança: 5.008-3 variação 51
Conta em nome de Mônica Pontalti
É necessário mandar o comprovante do depósito pelo email institutobaleiafranca@gmail.com (solicite também a ficha de inscrição).

Curso: Biologia, ecologia e conservação do boto-da-tainha (Tursiops truncatus)

Estão abertas as inscrições para o I Curso Teórico-Prático de Biologia, Ecologia e Conservação do Boto-da-Tainha (Tursiops truncatus), a se realizar nos dias 25 e 26 de agosto de 2012 na praia de Garopaba, Santa Catarina. Inscrições pelo e-mail institutobaleiafranca@gmail.com ou pelos telefones (48) 9963.1122 e (48) 9682.5718.

Mamíferos: da Terra aos Mares

A equipe do Laboratório de Ecologia de Mamíferos da Unisinos têm o prazer de convidar todos a participar da oficina Mamíferos: da Terra aos Mares.

A oficina visa apresentar o grupo dos mamíferos com aspectos de sua evolução, diversidade, ecologia, manejo, conservação e relações com o homem. A oficina ocorrerá nos dias 24 e 25 de agosto, e 1º de setembro de 2012, na Unisinos (Univerdade do Vale do Rio dos Sinos), em São Leopoldo, RS. As inscrições podem ser realizadas diretamente pela internet através do link: http://www.unisinos.br/extensao/eventos/EX120309/EX120309-00001/620/apresentacao.

DATAS: 24 e 25 de agosto, e 1º de setembro de 2012.


INVESTIMENTO: R$ 100,00.


INFORMAÇÕES: www.unisinos.br/eventos (eventos saúde).


CONTEÚDO PROGRAMÁTICO PREVISTO
A oficina será dividida em quatro módulos, sendo o primeiro módulo uma apresentação geral sobre características, diversidade e evolução dos mamíferos. Os quatro módulos seguintes apresentarão aspectos gerais e ecológicos sobre os mamíferos terrestres, e os quatro módulos seguintes apresentarão técnicas de estudo e monitoramento de populações de mamíferos marinhos, bem como suas interações com o homem.


O conteúdo detalhado previsto (sujeito a modificações) segue abaixo:


24/ago/2012
- Introdução geral: mamíferos, da terra aos mares (Msc Paulo T. Sarti, Fernando R.V. Lopes).

25/ago/2012

- Biologia e ecologia de pequenos mamíferos (Msc Maury S.L. Abreu).

- Padrões de microestrutura de pelos: identificando mamíferos (Nathalia S. Freitas).

- Mamíferos terrestres de médio e grande porte (Msc Paulo T. Sarti).

- O uso do habitat por mamíferos terrestres (Guilherme W. Schmitz).

01/set/2012

- Técnicas de estudo em mamíferos-marinhos: coleta, curadoria de coleção e estudos osteológicos (Biol. Ana Paula Costa).

- Técnicas de estudo em mamíferos-marinhos: monitoramento de populações (Biol. Rodrigo Machado, Biol. Ana Paula Costa, Fernando R.V. Lopes).

- Interações entre mamíferos aquáticos e a atividade pesqueira: da pesca cooperativa ao conflito (Biol. Rodrigo Machado).

- Dimensões humanas (Mônica Terra, Biol. Ana Carolina Pont).

Cetaceans registered on the coast of Ilhéus (Bahia), northeastern Brazil

BATISTA, R.L.G.; SCHIAVETTI, A.; SANTOS, U.A.; REIS, M.S.S. 2012. Cetaceans registered on the coast of Ilhéus (Bahia), northeastern Brazil. Biota Neotropica 12(1):000-000.

Abstract. Stranded cetaceans have scientific value and may confirm the occurrence of some species or indicate their geographical distribution in an area. The collection of biological material can also contribute to improve the knowledge of the species or populations inhabiting certain areas. This study aimed to record live or dead cetaceans found ashore along the coast of Ilhéus, Bahia State, northeastern Brazil. Data were collected through a campaign called "SOS strandings, whales, porpoises and dolphins." Between 1997 and 1999 three hundred posters and five hundred folders were distributed to beach huts, shops, fishing associations and settlements, the city’s municipal government, the Brazilian Environmental Agency (IBAMA) and fire stations. During this campaign, which lasted until 2007 it was possible to record 38 cetaceans of ten species on the coast of Ilhéus: Physeter macrocephalus, Megaptera novaeangliae, Globicephala macrorhynchus, Orcinus orca, Peponocephala electra, Stenella clymene, Feresa attenuata, Ziphius cavirostris, Steno bredanensis and Sotalia guianensis. The greatest numbers of records were observed between 2000 and 2003, which was the period after the distribution of banners and posters. The majority of the carcasses were recovered near the city downtown area (<10 km) and there was not a relationship between the state of the carcasses and the distance from that area.

Ecology of the water opossum Chironectes minimus in Atlantic forest streams of southeastern Brazil

GALLIEZ, M.; LEITE, M.S.; QUEIROZ, T.L.; FERNANDEZ, F.A.S. 2009. Ecology of the water opossum Chironectes minimus in Atlantic forest streams of southeastern Brazil. Journal of Mammalogy 90(1):93-103.

Abstract. We studied the population structure, spatial patterns, and activity patterns of the water opossum (Chironectes minimus) via capture-mark-recapture and radiotelemetry from October 2004 to October 2006 in Atlantic Forest streams in southeastern Brazil. We tested the hypothesis of reproductive seasonality, the usual pattern in neotropical marsupials, by examining recruitment of juveniles. The hypothesis was rejected, supporting the alternative hypothesis that breeding by water opossums was better explained by its habitat characteristics and prey availability than by its phylogenetic ancestry. The observed sex ratio was significantly biased toward males. The home lengths of individual water opossums varied from 844 to 3,724 m. Males had larger home lengths than females, and there were male-male and male-female overlaps. The longer home lengths for males may explain the observed sex ratio bias, because males are more exposed to capture. All individuals used stream stretches with preserved riparian forest, fast-flowing water, and stony substrate. The hypothesis that activity was homogeneously distributed throughout the night was rejected; activity began right after sunset and ended before sunrise, but with higher levels of activity in the first 6 h of the night. Because of anthropogenic alterations of hydrographic basins, water opossums may be threatened by reduction of their main habitat, streams with fast-flowing water and stony substrate.