Recursos alimentares nos estratos verticais e sua relação com pequenos mamíferos em uma Floresta de Araucária do sul do Brasil

ABREU, M.S.L.; SCHMITZ, G.W.; OLIVEIRA, L.R. 2015. Recursos alimentares nos estratos verticais e sua relação com pequenos mamíferos em uma Floresta de Araucária do sul do Brasil. Revista de Ciências Ambientais 9(2):131-144. doi: 10.18316/1981-8858.16

Abstract. Food resources on the vertical strata and their relationship with small mammals in an Araucaria forest of southern Brazil. This study presents the relationship between the use of different layers by non-volant small mammals and the food resources availability in an Araucaria Forest area from southern Brazil. In this sense, 150 live traps were placed on the ground, understory and canopy. The availability of resources in the layers was evaluated by counting fruits, seeds and captured invertebrates. As a result, 10 species were recorded of non-volant small mammals. An inverse relationship was found between captures of: Akodon montensis and availability of fruits and seeds on the ground (R = -0.95, P = 0.05); Juliomys sp. and invertebrates abundance in the canopy (R = -0.96, P = 0.04); and Gracilinanus microtarsus and total food availability in the canopy (R = -0.99, P = 0.008). The results suggest that in times of food scarcity, small mammals in the Araucaria Forest may need more time searching for food, increasing catch rates in the strata where they live.

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.

Treetop shelter of a Neotropical River Otter cuba (Lontra longicaudis - Carnivora: Mustelidae) in an Amazonian flooded forest

SANTOS, P.M.R.S.; KINUPP, V.F.; COLETTO-SILVA, A. 2007. Treetop shelter of a Neotropical River Otter cuba (Lontra longicaudis - Carnivora: Mustelidae) in an Amazonian flooded forest. Acta Amazonica 37(2):309-312.

Abstract. The finding of a Neotropical river otter (Lontra longicaudis) cub occupying a shelter in a hollowed treetop is reported. The observation was made in a seasonally flooded forest in Central Amazonia, during the high water peak of the annual inundation cycle. A literature review indicates that this is the first description of a shelter of the species, both in a hollowed tree and in Amazonia. This observation can indicate a strong relationship between the species’ breeding cycle with the annual dynamics of Amazonian rivers. We discuss potential advantages and disadvantages of breeding when water level is high.

Coexistence of jaguar (Panthera onca) and puma (Puma concolor) in a mosaic landscape in the Venezuelan llanos

SCOGNAMILLO, D.; MAXIT, I.E.; SUNQUIST, M.; POLISAR, J. 2003. Coexistence of jaguar (Panthera onca) and puma (Puma concolor) in a mosaic landscape in the Venezuelan llanos. Journal of Zoology, London 259:269-279.

Abstract. Jaguar Panthera onca and puma Puma concolor are sympatric throughout the jaguar’s distribution. Although several studies have focused on the interactions between these two predators, the ecological and behavioural factors that promote their coexistence remain unclear. The goal of this study was to identify those factors that facilitate the coexistence of these cats in a mosaic landscape in the Venezuelan llanos. The study was conducted from January 1996 until November 1998. Five jaguars and six pumas were captured and radio-collared. A high degree of spatial overlap was observed between jaguars and pumas, which may be related to the abundance and distribution of prey species. At a fine scale, there was little overlap of puma locations with jaguar locations. Both species were more active at night than during daytime, but seasonal differences were detected in the activity levels of these predators. Major segregation was found in food habits. Jaguars selected for large prey and pumas for medium-sized prey. Jaguars selected for capybara Hydrochaeris hydrochaeris and collared peccary Tayassu tajacu and consumed caiman Caiman crocodilus and white-tailed deer Odocoileus virginianus less than expected. Pumas selected just for collared peccary and also killed caiman less than expected. It is suggested that the abundance of medium-sized prey is an ecological factor that is facilitating the coexistence of jaguar and puma in the study area. Habitat heterogeneity may be another influential factor leading to the coexistence. Seasonal differences in activity levels probably reflect differences in the size and species of prey taken by these cats.

Short-term fire effects on small mammal populations and vegetation of the Northern Chihuahuan Desert

MONASMITH, T.J.; DEMARAIS, S.; ROOT, J.J.; BRITTON, C.M. 2010. Short-term fire effects on small mammal populations and vegetation of the Northern Chihuahuan Desert. International Journal of Ecology, v. 2010, Article ID 189271, 9 pages. doi: 10.1155/2010/189271.

Abstract. Fire is an important ecological factor in semidesert grass-shrub community dynamics, but there is a lack of designed field experiments documenting effects on vegetation and small mammals.We document effects of June prescribed fire on vegetation and small mammals on 20, 25-ha study areas in the Northern Chihuahuan Desert of Southern New Mexico, USA one month and one year posttreatment. Canopy cover of shrubs and grasses recovered to 68 and 27% of the preburn canopy cover, respectively, after one year. Prescribed burns during June enhanced short-term forb production by reducing competition from grasses and shrubs. Thirty thousand trap-nights yielded 1744 captures of 766 individuals of 15 small mammal species. Burns did not affect small mammal species richness and species diversity. Relative abundance of Merriam’s kangaroo rats (Dipodomys merriami) was 91% greater on burned sites than on control sites one year postburn. Silky pocket mouse (Perognathus flavus) relative abundance was 221% greater on burned sites one year postburn. Chihuahuan Desert pocket mice (Chaetodipus eremicus) responded negatively to the fire, with relative abundance 170% greater on control sites (P = .080). Burning produced short-term benefits for two heteromyids, Merriam’s kangaroo rats and silky pocket mice.

Modeling impacts of climate change on giant panda habitat

SONGER, M.; DELION, M.; BIGGS, A.; HUANG, Q. 2012. Modeling impacts of climate change on giant panda habitat. International Journal of Ecology, v 2012, Article ID 108752, 12 pages. doi: 10.1155/2012/108752.

Abstract. Giant pandas (Ailuropoda melanoleuca) are one of the most widely recognized endangered species globally. Habitat loss and fragmentation are the main threats, and climate change could significantly impact giant panda survival.We integrated giant panda habitat information with general climate models (GCMs) to predict future geographic distribution and fragmentation of giant panda habitat. Results support a major general prediction of climate change—a shift of habitats towards higher elevation and higher latitudes. Our models predict climate change could reduce giant panda habitat by nearly 60% over 70 years. New areas may become suitable outside the current geographic range but much of these areas is far from the current giant panda range and only 15% fall within the current protected area system. Long-term survival of giant pandas will require the creation of new protected areas that are likely to support suitable habitat even if the climate changes.

Elevational gradients in diversity of small mammals

MCCAIN, C.M. 2005. Elevational gradients in diversity of small mammals. Ecology 86(2):366-372.

Abstract. A global analysis of elevational diversity trends for nonvolant small mammals revealed a clear pattern of mid-elevational peaks in species richness. Fifty-six data sets were used to test the predictions of a null model (the mid-domain effect) and climatic hypotheses. Very few data sets fit entirely within the predictions of the null model, and the average predictive power of the null model was low. Regional (gamma) diversity fit the null model better than did local (alpha) diversity. Diversity peaked at higher elevations on taller mountains, consistent with climatic factors producing elevationally correlated habitat bands (Massenerhebung effect). This positive, linear relationship was documented for all data sets but was particularly pronounced for alpha diversity. Gamma diversity, which is generally highly influenced by area, exhibited a trend of highest diversity shifting toward lower elevations, and higher elevational peaks in species diversity at higher latitudes. The elevation of temperate diversity peaks exhibited a negative association with latitude. These results are evidence for the importance of a suite of interacting climatic, area, and geometric factors on elevational diversity patterns, apparent in spite of noise associated with different sampling techniques, localities, and historical pressures.

Effects of fire on the abundance of xenarthrans in Mato Grosso, Brazil

PRADA, M.; MARINHO-FILHO, J. 2004. Effects of fire on the abundance of xenarthrans in Mato Grosso, Brazil. Austral Ecology 29:568-593.

Abstract. Fire is an important ecological factor in Cerrado vegetation of central Brazil, and in other savanna

ecosystems. The effect of fire on the abundance of some Xenarthran mammal species Priodontes maximus

Kerr, 1792 (giant armadillo), Euphractus sexcinctus Linnaeus, 1758 (yellow armadillo) and Myrmecophaga tridactyla Linnaeus, 1758 (giant anteater)) was studied at Reserva Xavante do Rio das Mortes, a 329 000 ha Xavante Indian reserve in the Cerrado of Mato Grosso, Brazil. Track counts were used to compare the abundance of these mammals along seven burned and seven unburned transects, on seven occasions between August 1995 and August 1996. The number of tracks in burned and unburned areas did not differ. Xenarthrans probably use burned areas to obtain food resources, basically termites and ants. Xavante traditional fire hunts may reduce fuel accumulation and function as a mechanism to prevent more destructive fires. Fire management at Reserva Xavante is recommended because the burning system of Brazilian farmers is already influencing the Xavante community. Xavante traditional knowledge about fire could be an important instrument for this management.