Use of arboreal and terrestrial space by a small mammal community in a tropical rain forest in Borneo, Malaysia

WELLS, K. PFEIFFER, M.; LAKIM, M.B.; LINSENMAIR, K.E. 2004. Use of arboreal and terrestrial space by a small mammal community in a tropical rain forest in Borneo, Malaysia. Journal of Biogeography 31:641-652.

Abstract:
Aim: Small mammals were live-trapped in a primary rain forest to evaluate the relative distribution of species to each other and to microhabitat properties on the ground and in the canopy.
Location: Kinabalu National Park in Borneo, Sabah, Malaysia.
Methods: Seven trapping sessions were conducted along two grids with 31 trap points at distances of 20 m on the ground and in the lower canopy at an average height of 13.5 m.
Results: Species diversity and abundance of small mammals proved to be high: 20 species of the families Muridae, Sciuridae, Tupaiidae, Hystricidae, Viverridae and Lorisidae were trapped, with murids being dominant in both habitat layers. The terrestrial community was significantly more diverse with 16 captured species (Shannon–Wiener’s diversity index H'terr = 2.47), while 11 species were trapped in the canopy (H'arb = 1.59). The Whitehead’s rat, Maxomys whiteheadi, and the red spiny rat, Maxomys surifer, dominated the terrestrial community whereas the large pencil-tailed tree mouse, Chiropodomys major, was by far the most abundant species in the canopy. Other abundant species of the canopy community, the dark-tailed tree rat, Niviventer cremoriventer, and the lesser treeshrew, Tupaia minor, were also abundant on the ground, and there was no clear boundary between arboreal and terrestrial species occurrences.
Main Conclusions: As most species were not confined to specific microhabitats or habitat layers, species seemed to rely on resources not necessarily restricted to certain microhabitats or habitat layers, and separation of species probably resulted mainly from a species’ concentrated activity in a preferred microhabitat rather than from principal adaptations to certain habitats. Ecological segregation was stronger in the more diverse terrestrial community, though microhabitat selection was generally not sufficient to explain the co-occurrences of species and the variability between local species assemblages. Constraints on small mammal foraging efficiency in the three-dimensional more complex canopy may be responsible for the similarity of microhabitat use of all common arboreal species. Community composition was characterized by mobile species with low persistence rates, resulting in a high degree of variability in local species assemblages with similar turnover rates in both habitats.

New records of the red-rumped mouse Juliomys pictipes (Osgood, 1933) (Rodentia: Sigmodontinae) in coastal Atlantic Forest of Paraná, southern Brazil

CERBONCINI, R.A.S.; JUNIOR, C.M.M.; TIEPOLO, L.M.; PASSOS, F.C. 2014. New records of the red-rumped mouse Juliomys pictipes (Osgood, 1933) (Rodentia: Sigmodontinae) in coastal Atlantic Forest of Paraná, southern Brazil. Biotemas 27(1):159-164.

Abstract. Juliomys pictipes is a Sigmodontinae rodent endemic to the Atlantic Forest. Herein, we report the first records of the species on the coast of the state of Paraná, filling a gap in the species’ distribution. Records at low altitudes in the eastern part of the Serra do Mar conirm that the coastal mountains are not a barrier to the species’ distribution.

A radio tracking study of home range and movements of the marsupial Micoureus demerarae (Thomas) (Mammalia, Didelphidae) in the Atlantic forest of south-eastern Brazil

JUNIOR, E.A.M.; CHIARELLO, A.G. 2005. A radio tracking study of home range and movements of the marsupial Micoureus demerarae (Thomas) (Mammalia, Didelphidae) in the Atlantic forest of south-eastern Brazil. Revista Brasileira de Zoologia 22(1):85-91.

Abstract. From August 2001 to July 2002 the home range and movements of seven Micoureus demerarae (Thomas, 1905) (three males and four females) were investigated using radio tracking in the União Biological Reserve, state of Rio de Janeiro, south-eastern Brazil. A total of 436 locations was obtained and home range estimated with fixed Kernel (95% of data points), and minimum convex polygon (MCP) methods, with 100 and 95% of data points. Male home ranges estimated by MCP (100%) ranged from 5.4-24.2 ha and females from 0.3-10.7 ha. Corresponding figures calculated with Kernel (95%) were 4-10.9 ha for males and 1.3-5.9 ha for females. Animals travelled on average 423 m/night, with males travelling significantly further (582.8 m/night) than females (335.1 m/night) (t test, t = 3.609, p = 0.001). We concluded that radio tracking produced much larger home ranges than those estimated with traditional live-trapping techniques, suggesting that the latter might underestimate ranging when the area covered with traps is relatively small (ca. 1 ha or less). Radio tracking also indicated that M. demerarae, although predominantly arboreal and weighting only ca. 130 g., has movements similar in magnitude to larger-sized terrestrial didelphimorph marsupials, such as Didelphis Linnaeus, 1758, Philander Linnaeus, 1758 and Metachirus (Desmarest, 1817).

Frugivoria e potencial dispersão de sementes pelo marsupial Gracilinanus agilis (Didelphidae: Didelphimorphia) em áreas de Cerrado no Brasil central

CAMARGO, N.F.; CRUZ, R.M.S.; RIBEIRO, J.F.; VIEIRA, E.M. 2011. Frugivoria e potencial dispersão de sementes pelo marsupial Gracilinanus agilis (Didelphidae: Didelphimorphia) em áreas de Cerrado no Brasil central. Acta Botanica Brasilica 25(3):646-656.

Abstract. (Frugivory and potential seed dispersal by the marsupial Gracilinanus agilis (Didelphidae: Didelphimorphia) in areas of Cerrado in central Brazil). In the present study, we investigated patterns of fruit consumption and viability of seeds consumed by the marsupial Gracilinanus agilis (Burmeister, 1854) in four cerrado sites in central Brazil.  Faecal analysis indicated that this mammal feeds on seeds of pioneer plant species of Melastomataceae (Miconia albicans (Sw.) Triana, M. cuspidata Naudin, M. ferruginata DC., M. pepericarpa DC., M. pohliana Cogn. and Ossaea congestil ora (Naudin) Cogn.), Solanaceae (one unidentified species), and Viscaceae (Phoradendron perrottetii (DC.) Eichler, mistletoe). We recorded the highest reported rate of fruit consumption for Gracilinanus, with about 45% of the scats containing seeds and 86% containing items derived from fruits (N = 422). With the exception of O. congestiflora, the remaining seed species tested did not suffer negative effects on germination rates after passing through the marsupial guts. The analysis of intraspecific variation in the total number of Miconia seeds found in scats indicated that females defecate a significantly greater number of seeds (mean±EP = 21.7±3.8) than males (14.4±3.0) (F = 26.32; P < 0.0001). The factor season was also significant (F=452.22; P<0.0001) as well as the interaction between sex and season (F=30.10; P < 0.0001).  Both females and males increased their fruit consumption in the dry season, but in the rainy season females had more seeds than males in their faeces. Later during this season, we observed a higher number of Miconia seeds defecated by reproductive females (24.7±6.6) compared to non-reproductive females (12.9±2.8) (P = 0.031). Our results indicate that G. agilis feeds selectively on Melastomataceae, which suggests these plants play an important role in the diet of this marsupial in relation to energy and water demands, especially during the dry-cool season.

Arboreal tropical forest vertebrates: current knowledge and research trends

KAYS, R.; ALLISON, A. 2001. Arboreal tropical forest vertebrates: current knowledge and research trends. Plant Ecology 153:109-120.

Abstract. We review the ecology and specialized methods required for studying arboreal mammals, birds, reptiles and amphibians, and use faunal checklists from 12 tropical wet forest sites and an analysis of all articles published during the past ten years in 14 major journals to assess current knowledge and general research trends for these groups. The percentage of arboreal vertebrates was remarkably similar at the different sites (76.2+/-3.9%). Birds were the most arboreal group and amphibians and reptiles the least. The review of journals showed that primates were overwhelmingly the most studied group (336 papers), followed by bats (105), passeriform birds (73) and rodents (55). Judging by their portion of the arboreal vertebrate community and the number of papers surveyed, birds and amphibians and reptiles are vastly understudied compared to mammals, but this is largely due to the great number of primate studies. The number of publications on arboreal vertebrates has remained relatively stable over the last 10 years for all taxa except primates, which have seen a growth in publications. Canopy vertebrates from Brazil had by the most publications (120), followed by Madagascar (61), Costa Rica (55) and Indonesia (42). We conclude by highlighting the priorities we see for future studies on tropical canopy vertebrates.

Fotos: Juliomys sp.

Juliomys é um gênero de roedor arborícola neotropical com três espécies reconhecidas (J. pictipes, J. rimmofrons e J. ossitenuis). O gênero foi descrito recentemente, sendo que antigamente as espécies conhecidas eram parte do gênero Wilfredomys (hoje este gênero inclui apenas a espécie W. oenax). É um roedor muito pouco conhecido e pouco abundante nas áreas onde ocorre. O nome comum de cada espécie utiliza o termo "juliomys", portanto o nome comum do gênero seria pronunciado de maneira idêntica ao gênero.
Espécie: Juliomys sp.
Fotógrafo: Maury S.L. Abreu
Contato: maury.abreu@gmail.com

Fotos: Gracilinanus microtarsus

O nome gracilinanus vem do latim gracilis (delgado, fino) e do grego nanos (anão), enquanto o epíteto microtarsus vem do prefixo grego micro (pequeno) e o substantivo grego tarsos (tornozelo, sola do pé) (PIRES et al., 2010 - Mammalian Species 42(851):33-40).
Espécie: Gracilinanus microtarsus (cuíca graciosa, guaiquica, Brazilian gracile mouse opossum).
Fotógrafo: Maury S.L. Abreu
Contato: maury.abreu@gmail.com

Capturando pequenos mamíferos arborícolas

GRAIPEL, M.E.; MORAES, D.A. 2004. Capturando pequenos mamíferos arborícolas. Boletim da Sociedade Brasileira de Mastozoologia 39:1-2.

Este pdf é um texto curto, publicado no Boletim da Sociedade Brasileira de Mastzoologia em 2004 por Maurício Graipel e Diego Astúa. Interessante para quem trabalha ou pretende trabalhar com animais arborícolas.

Fotos: Kannabateomys amblyonyx

Dois indivíduos de rato-da-taquara, um roedor equimídeo (família Echimyidae) que ocorrem associados a taquarais. Estes roedores se alimentam essencialmente de brotos de bambu e são conhecidos por apresentarem comportamento social: vivem em casais e criam dos filhotes juntos. Procurei algum artigo sobre cuidado parental da espécie, mas não encontrei nada que estivesse disponível on-line.
Espécie: Kannabateomys amblyonyx (rato-da-taquara).
Fotógrafo: Maury S.L. Abreu.
Contato: maury.abreu@gmail.com.

Fotos: Armadilha de arame de dupla passagem

Existem armadilhas de arame (similar ao modelo Tomahawk) que funcionam de maneira diferente - elas possuem duas portas, uma de cada lado, e se fecham quando o animal tenta atravessar a armadilha. Estas armadilhas tem a vantagem de que não precisam de isca. Devem ser instaladas de maneira que os animais sejam capazes de passar por elas. Criar túneis e canais que obriguem o animal a entrar é uma boa estratégia.
Há um estudo sobre uso dessas armadilhas para captura de cuíca d'água (Chironectes minimus), instalando em córregos (Bressiani et al. 2008; acompanhem a próxima postagem).
Fotógrafo: Maury S.L. Abreu.
Contato: maury.abreu@gmail.com.

Fotos: Armadilha Tomahawk

Outro modelo de armadilha de captura viva tipicamente utilizado em levantamentos de pequenos mamíferos, o modelo Tomahawk consiste em uma gaiola. O animal fica menos protegido, mas há quem afirme que as tomahawks capturam animais que não são capturados nas Sherman. Também precisa de isca.
Nesta foto, a armadilha esta instalada em um suporte de madeira, preso por cordas para içar a armadilha até o dossel da floresta, permitindo assim captura de animais essencialmente arborícolas. É uma boa técnica em estudos de estratificação vertical. As armadilhas modelo Sherman também podem ser instaladas nesses suportes, assim como as de modelo Tomahawk também podem ser instaladas no solo e no sub-bosque (galhos e vegetação suspensa).
Fotógrafo: Maury S.L. Abreu.
Contato: maury.abreu@gmail.com.

Fotos: Armadilha Sherman

A técnica mais frequentemente utilizada para levantamentos de pequenos mamíferos é captura viva com armadilhas. Essa foto mostra uma armadilha modelo Sherman. Na foto ela esta instalada em um galho para captura de pequenos mamíferos arborícolas e escansoriais (como para estudos de uso do espaço vertical), mas o mais comum é instalar a armadilha no solo. Essas armadilhas possuem um gatilho no fundo, e quando o animal pisa, a porta se fecha, e só pode ser aberta pelo lado de fora. É necessário uso de isca.
Fotógrafo: Maury S.L. Abreu.
Contato: maury.abreu@gmail.com.

Movement distances and density estimation of small mammals using the spool-and-line technique

MENDEL, S.M.; VIEIRA, M.V. 2003. Movement distances and density estimation of small mammals using the spoll-and-line technique. Acta Theriologica 48(3):289-300.

Abstract. Edge effect is an inherent problem when using trapping grids to estimate density of small mammals, resulting in a sampling area larger than the area of the grid. Distances between captures of individuals are used to estimate A(W), the effective sampling area of a trapping grid, but grid size sets a limit for the largest detectable distance. The spool-and-line technique is proposed here as a new method to estimate A(W). Movement distances based on the spool-and-line technique were compared to similar movement distances based on capture-recapture of three spacies of marsupials of the Atlantic Forest of Brazil. Distances based on the two methos were uncorrelated, and only ln-transformed distances based on the spool-and-line were normally distributed. The maximum distance moved (MaxD) estimated by the spool-and-line was chosen as the more accurate and practical distance to estimate edge effect. Estimates of the effective sampling area and densities for the common opossum Didelphis aurita (Wied-Neuwied, 1826), were compared using MaxD based on spool-and-line (MaxDspool), capture-recapture (MaxDcap), and also the distance between traps (DT). MaxDspool reflected more accurately density variation between seasons. Movement distances of small mammals based on the spool-and-line technique permit more accurate estimates of density and its dynamics.

Tropical wildlife corridors: use of linear rainforest remnants by arboreal mammals

LAURANCE, S.G.; LAURANCE, W.F. 1999. Tropical wildlife corridors: use of linear rainforest remnants by arboreal mammals. Biological Conservation 91:231-239.

Abstract. In fragmented landscapes, linear forest remnants have the potential to provide habitat and movement corridors for wildlife. We used systematic spotlighting surveys to sample arboreal mammals in 36 linear rainforest remnants in tropical Queensland, Australia. The efects of corridor width, height, isolation, elevation, and floristic composition on mammals were assessed with multiple regression models. Six species were recorded during 108 surveys. The most vulnerable species, the lemuroid ringtail possum (Hemibelideus lemuroides), was found only in remnants comprised of primary rainforest that were linked to large tracts of continuous forest. Two other species, the Herbert River ringtail possum (Pseudochirulus herbertensis) and striped possum (Dactylopsila trivirgata), also favored corridors that were linked to forest tracts or fragments, with the former favoring high-diversity forest (primary forest or mixed regrowth) over low-diversity (Acacia) regrowth. Three other species, the coppery brushtail possum (Trichosurus vulpecula), green ringtail possum (Pseudochirops archeri), and Lumholtz's tree-kangaroo (Dendrolagus lumholtzi), occurred in both isolated and non-isolated remnants and both primary forest and regrowth. Our findings suggest that linear forest remnants that are floristically diverse (not Acacia-dominated regrowth) and at least 30±40 m width can function as habitat and probably movement corridors for most arboreal mammals in this region. The lemuroid ringtail, however, apparently requires corridors of primary rainforest of at least 200 m in width. Because the lemuroid ringtail is highly vulnerable to forest fragmentation, faunal corridors in this region should be designed wherever possible to meet its ecological requirements.

Divulgação: Padrões no uso do espaço arborícola e terrestre por pequenos mamíferos não voadores em uma área de Mata Atlântica no sul do Brasil

O estudo descrito abaixo esta sendo executado como projeto de Mestrado na Universidade do Vale do Rio dos Sinos - Unisinos pelo aluno Maury S.L. Abreu (contato: maury.abreu@gmail.com).

Resumo. A Mata Atlântica é um dos biomas mais diversos e ameaçados do mundo. A intensa degradação e fragmentação reduziram esse bioma a cerca de 8% de sua formação original. Estes processos resultam na perda da diversidade de microhabitats e redução da heterogeneidade e complexidade ambiental, importantes componentes da riqueza de espécies. A região sul do Brasil é muito carente de informações sobre a diversidade de pequenos mamíferos acima do solo e as relações entre esses organismos e variáveis ambientais. Neste sentido, este estudo pretende analisar a diversidade de pequenos mamíferos não voadores ao longo dos estratos verticais de uma área de Mata Atlântica no Rio Grande do Sul e suas relações com variáveis ambientais. O estudo esta sendo realizado no Centro de Pesquisa e Conservação da Natureza “Pró-Mata” através de  uma amostragem por estação do ano (verão, outono, inverno e primavera) por meio de captura, marcação e recaptura de pequenos mamíferos com armadilhas instaladas no solo, no sub-bosque e no dossel. Será estimada a complexidade e heterogeneidade do ambiente usando técnicas descritas na literatura. Também serão medidas 11 variáveis de microhabitat que podem influenciar a presença das espécies estudadas. A disponibilidade de recursos alimentares (frutos, sementes e invertebrados) será estimada em cada estrato utilizando armadilhas de queda (pitfalls) e armadilhas adesivas (fitas pega-mosca). Os pequenos mamíferos são de grande importância para a conservação e manutenção do equilíbrio dos ecossistemas porque são a base alimentar de muitos vertebrados, atuam como dispersores de sementes, potenciais polinizadores e influenciam uma série de outros componentes ecológicos das comunidades em que ocorrem.