Search

Species distributions and the mechanisms that produce patterns in the occupation space are recurrent themes in community ecology. Here, we examine beta diversity among assemblages of small mammals in the Cerrado domain of Brazil to partition the effects of turnover and nestedness on species distributions. Our objective was to evaluate whether balanced spatial variation in abundance (β bal) and abundance gradients (β gra) are congruent within and among habitats and localities of the Brazilian Cerrado. In addition, we wanted to understand whether ecological mechanisms, such as dispersal limitation, habitat filtering, and species sorting, drive the distribution patterns of the Cerrado small mammals. We analyzed the occurrence and abundances of small mammals from 16 localities widely distributed across the Cerrado biome, and grouped our data with respect to two distinct spatial scales. Baselga's Bray–Curtis index of dissimilarity and its respective partitions, i.e. balanced variation in abundance (β bal) and abundance gradients (β gra), were estimated between sampling units at the two spatial scales. Thus, we used exponential models to search for distance decay in species similarity between pairs of localities and between similar habitats. Our results show that differences between small mammal assemblages in the Cerrado are driven mainly by species replacement rather than independent gain or loss of species, both at small and large scales. The spatial turnover patterns of small mammals in the Cerrado biome are determined by a combination of large scale (biogeographic, spatial) and local mechanisms (low dispersal and habitat specificity). However, processes occurring at small scales seem to be more important in species sorting than processes occurring at large scales. The spatial configuration of the landscape and the extent and quality of habitats strongly influence the rate of species turnover in Cerrado. Thus, protecting the different types of habitats should be of prime importance to conserving the diversity of Cerrado small mammals. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

White-lipped peccaries (Tayassu pecari) are important seed predators and dispersers throughout the Neotropics. Because they occur in groups as large as 300 individuals, they need large areas to persist. We investigated home-range size and overlap of 13 groups using radiotelemetry data from 3 years of monitoring in the Emas National Park and surrounding farmland in central Brazil. Average home-range sizes were 1,710.64 ha for 50% of the locations and 8,659.99 ha for 95% based on minimum convex polygons and 790.38 ha for 50% of the locations and 7,986.92 ha for 95% based on the fixed kernel estimator. Home-range size did not correlate with group size, the monitoring period, or the number of locations obtained. Home ranges were larger during the wet season than the dry season. Average home-range overlap among groups was 31%; there were no significant differences in overlap between seasons. Home ranges varied seasonally, most likely in response to the dynamic landscape of crop plantations surrounding the park. Although the peccaries fared well in the heterogeneous agricultural landscape surrounding the park, conflict with farmers due to crop damage and landscape changes due to expansion of sugarcane plantations need to be addressed by conservation strategies. [ABSTRACT FROM AUTHOR]

The impact of deforestation and fragmentation upon ecologically important and poorly known groups is currently an important issue for conservation biology. Herein we describe xenathran communities across the Brazilian Cerrado and study the effects of habitat fragmentation on occupancy and activity patterns on these assemblages. Our hypothesis was that larger and specialized species would be more ecologically sensitive, and likely to exhibit shifts in their activity patterns in more deforested areas as a way of dealing with the myriad of effects involved in the fragmentation process. The study was conducted by camera trapping in ten Cerrado sites. Five species were analyzed: Priodontes maximus, Euphractus sexcinctus, Dasypus novemcintus (Order Cingulata), Tamandua tetradactyla and Myrmecophaga tridactyla (Order Pilosa). Fragmentation was quantified by landscape metrics, calculated on scales that matched the species' home ranges. Occupancy and detection probability analyses were conducted to test for shifts in occupancy under different fragmentation conditions. A mixed-effects model analysis was conducted to test for shifts in species' frequency of records related to time of day, controlling for spatial autocorrelation by means of eigenvector-based spatial filters for the models' residuals. There were no changes in activity pattern between more and less fragmented areas, so that our behavioural plasticity hypothesis was not corroborated for this group. The lack of changes in the patterns could be explained by a species' time-lag response, or by the lack of a wide enough fragmentation gradient in our study. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We report the first estimate of jaguar density in the semi-arid caatinga biome of north-eastern Brazil. During August-October 2007, in the Serra da Capivara National Park, we used camera traps to identify and count jaguars. Jaguar abundance and density were calculated using mark-recapture models. In a sampling effort of 1,249 camera-trapnights we identified 12 adult jaguars and estimated an abundance of 14 ± SE 3.6 jaguars in an area of 524 km2, i.e. a density of 2.67 ± SE 1.00 jaguars per 100 km2. This estimate is higher than in most other Brazilian biomes and indicates Serra da Capivara National Park as an important reserve for protecting jaguars in north-eastern Brazil. [ABSTRACT FROM AUTHOR]

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 speciesPriodontes maximusKerr, 1792 (giant armadillo),Euphractus sexcinctusLinnaeus, 1758 (yellow armadillo) andMyrmecophaga tridactylaLinnaeus, 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. [ABSTRACT FROM AUTHOR]

Habitat association of the spiny rat, Proechimys roberti (Rodentia: Echimyidae), was studied in the National Park of Brasília from October 1998 to June 1999. Thirty-three captures and 25 individuals were recorded with an effort of 1907 trap-nights. Stepwise logistic regression revealed a significant positive association between the presence of babaçu palms and the probability of occurrence for P. roberti ( p = 0.0006, df = 1). Stepwise multiple linear regression identified mean gallery forest width between sampling areas as a marginally significant variable in predicting capture success for this species ( p = 0.056, df = 1). The results of this study suggest that P. roberti selects for specific microhabitats within the heterogeneous gallery forest environment. [ABSTRACT FROM AUTHOR]

Investigates the food items consumed by sympatric manned wolves, crab-eating foxes and haory foxes in the Cerrado biome of central Brazil to determine overlap among their diets. Home ranges and spatial segregation among the canids; Determination of the importance of each food item through relative frequency; Habitat use by the canids.

Eight lesser anteaters Tamandua tetradactyla rescued from the rising waters of a dam at Serra da Mesa, Minaçu, Goiás, Brazil, were tranlocated to other areas and tracked using radio telemetry for periods of up to 10 months, from December 1996 through February 1998. With the exception of one, or perhaps two, female(s) that left the area while the radio collars were in place, the anteaters stayed within 2.17 km of their release sites and appeared to thrive. The results suggest that it is feasible to translocate small numbers of anteaters into new areas of suitable habitats without adverse effects on resident anteaters. [ABSTRACT FROM AUTHOR]

We aimed to assess the potential impact of climate change on the geographic distribution of areas holding suitable climatic conditions for the presence of Lycalopex vetulus , and to discuss the implications of such distribution for the conservation of the species. We employed correlative modeling analyses to infer the geographic distribution of climatically suitable conditions for the species on climatic scenarios for the present and for years 2050 (average for 2041–2060) and 2070 (average for 2061–2080). The data consisted of species occurrences and 5 bioclimatic variables containing interpolated and averaged information on seasonal variation of temperature and precipitation. Models were projected onto climatic scenarios employing three different global circulation models and two representative concentration pathways. For each of these scenarios, we quantified the expected changes in area (km2) holding suitable climatic conditions and how much of that area is expected to be within the current Brazilian system of protected areas. Our results reveal that climate change represents a major threat for the survival of L. vetulus by drastically reducing its habitat availability in a period of time no longer than five decades from now. Experimental physiological and behavioral studies are necessary to assess whether L. vetulus is able to adequately tolerate under climatic conditions different to those under which the species is currently present. [ABSTRACT FROM AUTHOR]

We report two new localities for the rodent species Wiedomys cerradensis Gonçalves, Almeida and Bonvicino, 2005, previously known only from its type locality, in southwestern Bahia state, and one neighbor locality. Three new specimens were collected along the Paranã River Valley, in the Goiás and Tocantins states, central Brazil. These records extend the range of this species to the northwest, approximately 190 km. We provide external and cranial measurements of these specimens and comment on their morphology. [ABSTRACT FROM AUTHOR]

Abstract: The planning of protected areas take into consideration the current distributions of target species, disregarding possible future range shifts under climate change. This study tested potential shifts in the distribution of three xenarthran species (the giant anteater, Myrmecophaga tridactyla; the giant armadillo, Priodontes maximus; and the three-banded armadillo, Tolypeutes tricinctus) due to the effects of climate change under different dispersal scenarios. In addition, we tested the adequacy of the current Brazilian protected areas in preserving these species under future climate changes (future distribution for the year 2050), under full and null dispersal scenarios. The final occurrence maps were then confronted with two Brazilian reserve systems for the year 2010: one consisting of reserves for integral protection only (IPCU), and one that included also reserves for sustainable use and indigenous reserves (SUCU). In the IPCU system, none of the species have or will have ⩾10% of their distributions protected, under neither dispersal scenario. Including SUCU, however, M. tridactyla and P. maximus already are, and will still be, adequately protected in the future. T. tricinctus, which is endemic to the Brazilian semi-arid, will not reach the 10% goal under neither dispersal scenario, even under the SUCU system. We stress the need for management actions in the northeastern and central parts of Brazil. Opportunities for the creation of more reserves are highlighted, considering the potential range shifts and the natural habitats still present in these regions. [Copyright &y& Elsevier]

Abstract: We analysed microhabitat use by the rodents Calomys tener, Necromys lasiurus and Thalpomys lasiotis and the factors that may influence their abundances in “murundu” grasslands (open fields with termite mounds) at Aguas Emendadas Ecological Station, Planaltina, Federal District, Brazil. Two grids with 100 sampling points were established and traps were placed at each intersection of the grid, where five microhabitat variables were also measured. Rodents were trapped from June through October 2008. Microhabitat explained 21% of the variation in community structure, with grass density and the number of termite mounds explaining most of the variation. Necromys lasiurus was most often captured in areas with dense grasses, whereas T. lasiotis and C. tener were most often in areas less dense with grasses. [Copyright &y& Elsevier]

Maned wolves are large canids currently considered vulnerable to extinction due to habitat loss. They are still commonly found within the urban mesh inside the Brazilian Federal District (Distrito Federal--DF), in nearby Protected Areas (PAs), and in surrounding farms. We evaluated the genetic diversity of maned wolves in three PAs of the DF, using both invasive and noninvasive techniques to obtain DNA that was later amplified for five microsatellite markers. We sampled 23 wolves: 10 with the noninvasive method, three captured in traps, six road-killed, and four rescued in urban areas. In Águas Emendadas Ecological Station (ESECAE) we also used samples from six specimens captured between 1997 and 1998 for a temporal comparison. For maned wolves, non-invasive techniques are affordable and easier to conduct in the field, while laboratory costs are much lower for invasive samples. Hence, a sampling strategy combining both techniques may provide an interesting approach for molecular ecology studies requiring comprehensive coverage of local individuals. On the basis of such integrated sampling scheme, our analyses indicated that none of the investigated populations currently present deviations from Hardy-Weinberg expectations or indication of inbreeding. Furthermore, in ESECAE there was no reduction in genetic diversity during the last 9 years. Overall, maned wolves did not present evidence of genetic structuring among the three sampled PAs. These results thus indicate that individual exchange among PAs is still occurring at sufficient rates to avoid differentiation, and/or that the recent fragmentation in the region has not yet produced measurable effects in the genetic diversity of maned wolves.

Conserving animals beyond protected areas is critical because even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of landscape features that will promote persistence of a diverse array of species is a high priority, particularly, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado, the world's most biologically diverse savanna. Emas Park is a large-mammal global conservation priority area but is too small to protect wide-ranging mammals for the long-term and conserving these populations will depend on the landscape surrounding the park. We employed novel, noninvasive methods to determine the relative importance of resources found within the park, as well as identify landscape features that promote persistence of wide-ranging mammals outside reserve borders. We used scat detection dogs to survey for five large mammals of conservation concern: giant armadillo (Priodontes maximus), giant anteater (Myrmecophaga tridactyla), maned wolf (Chrysocyon brachyurus), jaguar (Panthera onca), and puma (Puma concolor). We estimated resource selection probability functions for each species from 1,572 scat locations and 434 giant armadillo burrow locations. Results indicate that giant armadillos and jaguars are highly selective of natural habitats, which makes both species sensitive to landscape change from agricultural development. Due to the high amount of such development outside of the Emas Park boundary, the park provides rare resource conditions that are particularly important for these two species. We also reveal that both woodland and forest vegetation remnants enable use of the agricultural landscape as a whole for maned wolves, pumas, and giant anteaters. We identify those features and their landscape compositions that should be prioritized for conservation, arguing that a multi-faceted approach is required to protect these species.

Tick species parasitizing yellow armadillo, Euphractus sexcinctus, were recorded from October 2006 to October 2007 in Pantanal. A total of 89 ticks were collected from 23 yellow armadillos. Most ticks (n=50) were identified as Amblyomma cajennense (Fabricius) (32 males and 18 females). The only other species found was Amblyomma parvum (Aragão) (three females and two males). The remaining ticks were immatures of Amblyomma (29 nymphs and five larvae). The prevalence of A. cajennense was 55%, the mean intensity was 2.7±0.5 (SE) (n=17) and the mean abundance was 1.5±0.4 (n=31).