sábado, 29 de setembro de 2012

Toward an ecological synthesis: a case for habitat selection

MORRIS, D.W. 2003. Toward an ecological synthesis: a case for habitat selection. Oecologia 136:1-13.

Abstract. Habitat selection, and its associated density and frequency-dependent evolution, has a profound influence on such vital phenomena as population regulation, species interactions, the assembly of ecological communities, and the origin and maintenance of biodiversity. Different strategies of habitat selection, and their importance in ecology and evolution, can often be revealed simply by plots of density in adjacent habitats. For individual species, the strategies are closely intertwined with mechanisms of population regulation, and with the persistence of populations through time. For interacting species, strategies of habitat selection are not only responsible for species coexistence, but provide one of the most convenient mechanisms for measuring competition, and the various community structures caused by competitive interactions. Other kinds of interactions, such as those between predators and prey, demonstrate that an understanding of the coevolution of habitat-selection strategies among strongly interacting species is essential to properly interpret their spatial and temporal dynamics. At the evolutionary scale, the frequency dependence associated with habitat selection may often allow populations to diverge and diversify into separate species. Habitat selection thereby demonstrates how we can map microevolutionary strategies in behavior onto their population and community consequences, and from there, onto macroevolutionary patterns of speciation and adaptive radiation. We can anticipate that future studies of habitat selection will not only help us complete those maps, but that they will also continue to enrich the panoply of ideas that shape evolutionary ecology.

sábado, 22 de setembro de 2012

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.

quinta-feira, 20 de setembro de 2012

Road Ecology Brazil 2013

O Centro Brasileiro de Estudos em Ecologia de Estradas tem acaba de disponibilizar a primeira circular de lançamento do Road Ecology Brazil 2013. Todas as informações podem ser lidas no site:

http://issuu.com/reb_2013/docs/reb_2013_circular_0

Todos os endereços para contato estão disponíveis neste link.

sábado, 15 de setembro de 2012

Disponibilidade de frutos e a dieta de Lycalopex vetulus (Carnivora - Canidae) em um cerrado de Mato Grosso, Brasil

DALPONTE, J.C.; LIMA, E.S. 1999. Disponibilidade de frutos e a dieta de Lycalopex vetulus (Carnivora - Canidae) em um cerrado de Mato Grosso, Brasil. Revista Brasileira de Botânica 22(2):325-332.

Abstract. (Fruit availability and the diet of Lycalopex vetulus (Carnivora - Canidae) in a cerrado vegetation of Mato Grosso, Brazil). The fruiting phenology of 41 species known as potential food for mammals was monitored monthly during the period of 1985 and 1986, and compared with the frugivorous diet of the hoary fox (Lycalopex vetulus) in a cerrado area near Chapada dos Guimarães National Park, Mato Grosso, Brazil. The fruiting pattern was seasonal, with peaks of greater availability in the beginning of dry and wet seasons. Hancornia speciosa, Rauwolfia sp. and Solanum lycocarpum showed a long (nine to 12 months) fruiting pattern, while Guettarda viburnioides and Mouriri elliptica a short pattern (five to eight months). Seventy percent of the fruit species were eaten by the hoary fox. Despite the large number of fruit species consumed, a small percentage (26%) of these species reaches 10% of the occurrence frequency in the fox scats. The consumption of fruits by the hoary fox was opportunistic, generally consistent with the seasonal fruiting pattern in the study area. H. speciosa and S. lycocarpum were considered the most important fruit species in the diet of the hoary fox, since they give sources of alternative food year round, including periods of low availability of other fruits, like the peak os dry season. Changes in the intensity of fruit used by the hoary fox, like the replacement of some species by others, seem to show states of satiation and interest for new atractive fruits. Apparently, accessibility, strong smell and energetic content are features of the fruits that determine primary preferences for some species. The role of the hoary fox as an important agent to diesperse fruits in the cerrado may be suggested by the large number of fruit species eaten, and by the presence of undamaged seeds in the scats.

terça-feira, 11 de setembro de 2012

Daily activity patterns of the Atlantic bamboo rat (Kannabateomys amblyonyx) in southern Brazil.

SARTI, P.T; SILVA, R.B.; VIEIRA, E.M. 2012. Daily activity patterns of the Atlantic bamboo rat (Kannabateomys amblyonyx) in southern Brazil. Neotropical Biology and Conservation 7(2):108-113.

Abstract. Several biotic and abiotic factors influence on daily cycles and mammalian life-history patterns. In this paper, we investigated behavioral patterns and diurnal and nocturnal activity of the Atlantic bamboo rat Kannabateomys amblyonyx (Rodentia, Echimyidae) an endemic species of the Brazilian Atlantic Forest. We conducted the study in the southern portion of the species distribution, in patches of an introduced bamboo species (Bambusa tuldoides) that occurred inside native forest areas. We evaluated behavior and activity time of the individuals by conducting scans during nocturnal and diurnal periods (mean scan length – 24 min, range from 2 to 30 min). We considered the following behavioral categories: feeding, moving, self-cleaning and resting. We did not find significant difference between the diurnal and nocturnal activity (randomized MANOVA, SS = 0.07, d.f. = 45, P = 0.59). The Atlantic Bamboo Rat seemed to be active during the entire 24-h daily period, but with activity peaks by the beginning of the night (between 19:00 and 21:00). The low energy quality provided by food (buds, twigs and bamboo leaves) should compel the rodent to eat several times a day in order to supply their metabolic needs. Besides that, predator activity both during day and night, as well as other local environmental characteristics, probably represents relevant factors that influence the 24-h activity patterns of the studied rodent.


sábado, 8 de setembro de 2012

Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia)

BININDA-EMONDS, O.R.P.; GITTLEMAN, J.L.; PURVIS, A. 1999. Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia). Biol. Rev. 74:143-175.

Abstract. One way to build large, more comprehensive phylogenies is to combine the vast amount of phylogenetic information already available. We review the two main strategies for accomplishing this (combining raw data versus combining trees), but employ a relatively new variant of the latter: supertree construction. The utility of one supertree technique, matrix representation using parsimony analysis (MRP), is demonstrated by deriving a complete phylogeny for all 271 extant species of the Carnivora from 177 literature sources. Beyond providing a 'consensus' estimate of carnivore phylogeny, the tree also indicates taxa for which the relationships remain controversial (e.g. herpestids, viverrids, and intrageneric relationships in the procyonids). Times of divergence throughout the tree were also estimated from 74 literature sources based on both fossil and molecular data. We use the phylogeny to show that some lineages within the Mustelinae and Canidae contain significantly more species than expected for their age, illustrating the tree's utility for studies of macroevolution. It will also provide a useful foundation for comparative and conservational studies involving the carnivores.

terça-feira, 4 de setembro de 2012

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).

sábado, 1 de setembro de 2012

Small mammal community structure and composition in the Cerrado Province of central Brazil

MARES, M.A.; ERNEST, K.A.; GETTINGER, D.D. 1986. Small mammal community structure and composition in the Cerrado Province of central Brazil. Journal of Tropical Ecology 2:289-300.

Abstract. Community structure, microhabitat selection, and patterns of species co-occurrence were examined during a 14-month study of small mammals in the Cerrado Province of central Brazil. Data were collected from mark-recapture grids in brejo and gallery forest, and from live-trapping and specimen collection in all habitat types withing cerrado (campo limpo, campo sujo, cerrado [s.s.], cerradão, brejo, valley-side wet campo, and gallery forest). Gallery forest supported the highest species richness, most complex vertical distribution of species, highest level of trophic diversity, and highest macroniche diversity. Degree of habitat selection varied widely. All habitat types supported both rodents and marsupials, althought marsupials tended to be much less common in the grasslands (campos) than in woodlands (cerrado) and forest (cerradão, gallery forest). Some species, such as Didelphis albiventris, occurred in all habitat types, while others were much more restricted. Oryzomys bicolor, for example, ocurred only in gallery forest. No habitat type has a completely distinct fauna: overlap in species composition always occurred with at least one other habitat type. Because of the great variability of habitats, and the fact that subsets of the mammal fauna were frequently habitat specific, the overall species richness of any portion of mixed cerrado vegetation is remarkably high.