Time filter

Source Type

Raboy B.E.,Smithsonian Conservation Biology Institute | Raboy B.E.,Institute Estudos Socioambientais Do sul da Bahia | Raboy B.E.,Center for Research and Conservation | Neves L.G.,Institute Estudos Socioambientais Do sul da Bahia | And 7 more authors.
Primate Conservation | Year: 2013

The golden-headed lion tamarin, Leontopithecus chrysomelas, was formerly thought to range below 300-400 m above sea level, because of changes in forest physiognomy and lack of resources at higher elevations. We document four cases (from two studies) of L. chrysomelas ranging above 500 m, and investigate the behavior of two groups that ranged from 100 to 700 m. We discuss the possibilities that 1) resources may be more abundant at higher elevations than previously thought, 2) a shift may have occurred in the species elevation-use patterns in response to forest loss and degradation at lower elevations, and that 3) golden-headed lion tamarins require low elevations for access to resources but use higher altitudes to travel between lower lying areas. Understanding exactly how L. chrysomelas uses higher elevations and the limits of its upper ranging patterns has significant conservation implications for this endangered species. Even without being able to definitively ascertain that golden-headed lion tamarins are able to settle in stable home ranges at higher elevations with adequate resources for breeding and survival, they certainly move through these habitats. We suggest, therefore, that slopes and ridge-tops should be taken into account as corridors to be preserved for gene flow in the otherwise highly fragmented L. chrysomelas metapopulation.


Raboy B.E.,Smithsonian Institution | Raboy B.E.,Institute Estudos Socioambientais do Sul da Bahia | Neves L.G.,Institute Estudos Socioambientais do Sul da Bahia | Neves L.G.,University Estadual Of Santa Cruz | And 7 more authors.
Biotropica | Year: 2010

We investigated the effects of forest fragmentation on golden-headed lion tamarins (Leontopithecus chrysomelas) by qualitatively and quantitatively characterizing the landscape throughout the species range, conducting surveys, and exploring predictive models of presence and absence. We identified 784 forest patches that varied in size, shape, core area, habitat composition, elevation, and distance to neighboring patches and towns. We conducted 284 interviews with local residents and 133 playback experiments in 98 patches. Results indicated a reduction in the western portions of the former species range. We tested whether L. chrysomelas presence or absence was related to the aforementioned fragmentation indices using Monte Carlo logistic regression techniques. The analysis yielded a majority of iterations with a one-term final model of which Core Area Index (percent of total area that is core) was the only significant type. Model concordance ranged between 65 and 90 percent. Area was highlighted for its potential predictive ability. Although final models for area lacked significance, their failure to reach significance was marginal and we discuss potential confounding factors weakening the term's predictive ability. We conclude that lower Core Area Index scores are useful indicators of forest patches at risk for not supporting L. chrysomelas. Taken together, our analyses of the landscape, survey results, and logistic regression modeling indicated that the L. chrysomelas metapopulation is facing substantial threat. The limited vagility of lion tamarins in nonforest matrix may lead to increasingly smaller and inbred populations subject to significant impact from edge effects and small population size. Local extinction is imminent in many forest patches in the L. chrysomelas range. © 2009 The Author(s). Journal compilation © 2010 by The Association for Tropical Biology and Conservation.


De Almeida Rocha J.M.,Federal University of Rio de Janeiro | De Almeida Rocha J.M.,Institute Estudos Socioambientais do Sul da Bahia | De Almeida Rocha J.M.,University Estadual Of Santa Cruz | Dos Reis P.P.,Institute Estudos Socioambientais do Sul da Bahia | And 5 more authors.
Folia Primatologica | Year: 2014

During play, primates may become more vulnerable to predation. Our goal was to examine the potential role of predation risk on the play behavior of 3 groups of goldenheaded lion tamarin, Leontopithecus chrysomelas , in shaded cocoa agroforest (cabruca) of Southern Bahia, Brazil. We identified the preferred (and safer) locations on vertical strata during playtime and investigated if frequency and duration of play differed according to group size. All groups preferred to play on the lower levels of vertical strata, which may be perceived as either a safer environment or as a more suitable location for play due to the vegetation structure. The smallest group played less than the others, while the largest group played more and for longer periods. Our data suggest that predation risk can influence where play takes place as well as its frequency and length. © 2014 S. Karger AG, Basel.


Cassano C.R.,University of Sao Paulo | Cassano C.R.,Institute Estudos Socioambientais do Sul da Bahia | Barlow J.,Lancaster University | Pardini R.,University of Sao Paulo
Biotropica | Year: 2012

The forest-like characteristics of agroforestry systems create a unique opportunity to combine agricultural production with biodiversity conservation in human-modified tropical landscapes. The cacao-growing region in southern Bahia, Brazil, encompasses Atlantic forest remnants and large extensions of agroforests, locally known as cabrucas, and harbors several endemic large mammals. Based on the differences between cabrucas and forests, we hypothesized that: (1) non-native and non-arboreal mammals are more frequent, whereas exclusively arboreal and hunted mammals are less frequent in cabrucas than forests; (2) the two systems differ in mammal assemblage structure, but not in species richness; and (3) mammal assemblage structure is more variable among cabrucas than forests. We used camera-traps to sample mammals in nine pairs of cabruca-forest sites. The high conservation value of agroforests was supported by the presence of species of conservation concern in cabrucas, and similar species richness and composition between forests and cabrucas. Arboreal species were less frequently recorded, however, and a non-native and a terrestrial species adapted to open environments (Cerdocyon thous) were more frequently recorded in cabrucas. Factors that may overestimate the conservation value of cabrucas are: the high proportion of total forest cover in the study landscape, the impoverishment of large mammal fauna in forest, and uncertainty about the long-term maintenance of agroforestry systems. Our results highlight the importance of agroforests and forest remnants for providing connectivity in human-modified tropical forest landscapes, and the importance of controlling hunting and dogs to increase the value of agroforestry mosaics. © 2012 by The Association for Tropical Biology and Conservation.


Cassano C.R.,University Estadual Of Santa Cruz | Cassano C.R.,University of Sao Paulo | Cassano C.R.,Institute Estudos Socioambientais do Sul da Bahia | Barlow J.,Lancaster University | Pardini R.,University of Sao Paulo
Biological Conservation | Year: 2014

Changes in biodiversity and ecosystem services in terrestrial systems are being driven by the synergistic interactions between the loss of native vegetation and land-use intensification. Disentangling the influence of these two processes on species persistence is an important step towards reconciling conservation and agriculture production. We investigated how forest cover and management intensification affect the conservation value of cacao agroforests for mammals in an Atlantic forest landscape in southern Bahia, the most extensive area of diverse shaded cacao plantations in Brazil. Although both factors affected the distribution of mammal species, management intensification had a stronger effect, negatively affecting a larger number of species. Frequency of domestic dogs, an indirect aspect of management intensification, negatively affected four species and lower connectivity of shading trees decreased the use of cacao agroforests by three species of conservation concern. In comparison, the reduced forest cover negatively affected two species of conservation concern. Our results suggest that controlling domestic dog populations is particularly valuable for large mammal conservation in agroforestry mosaics, since it does not affect crop productivity. Improving shade cover within agroforests, on the other hand, should be implemented carefully, maintaining acceptable yield while promoting canopy connectivity and the recruitment of tree species used by forest dependent mammals. However, the importance of both local management intensification and local forest cover are likely to be context dependent, and changes in their relative importance are likely to occur with different levels of deforestation at the landscape scale. © 2013 Elsevier Ltd.


Oliveira L.C.,University of Maryland University College | Oliveira L.C.,Institute Estudos Socioambientais do Sul da Bahia | Hankerson S.J.,University of Maryland University College | Dietz J.M.,University of Maryland University College | Raboy B.E.,Institute Estudos Socioambientais do Sul da Bahia
Animal Conservation | Year: 2010

The golden-headed lion tamarin Leontopithecus chrysomelas occurs in the Atlantic forest of southern Bahia, Brazil, where shade-cocoa agroforestry (known as cabruca) predominates. The economic decline of the cocoa industry has caused many landowners to convert cabruca into cattle pasture or diversify their plantations with other crops. These and prior anthropogenic disturbances such as habitat fragmentation are threatening lion tamarin persistence. For some lion tamarin groups, cabruca comprises a large part of their home range. Considering these factors, the maintenance of the biological diversity in cabruca favorable to golden-headed lion tamarins is of considerable interest to their long-term survival. Here we identify plant species that provide food and sleeping sites for the lion tamarins and examine their occurrence in cabruca plantations, in order to investigate alternatives for conservation management practices that benefit both lion tamarins and cabruca. We determined the total number of trees and the frequency of individuals and species used for food and sleeping sites by lion tamarins in Una Biological Reserve, Bahia, from 1998 to 2006. We used this information to compare the richness and frequency of use across habitats (cabruca, mature and secondary) and to create a ranking index considering various components of a tree species' utility to the lion tamarins. Lion tamarins used 155 tree species, 93 for food and 93 for sleeping sites. Fifty-five species were ranked as 'Extremely Valuable,' eight as 'Valuable' and 92 as 'Of Interest.' Of 48 families, Myrtaceae and Sapotaceae were used the most. Cabruca contained fewer individual trees used by lion tamarins, but the highest frequency of use per tree compared with other habitats, indicating the large influence of single trees in these plantations. Using the key tree species identified in our study in the management of cabruca would be of considerable benefit to the long-term survival of lion tamarins. © 2009 The Authors. Journal compilation © 2009 The Zoological Society of London.


Zeigler S.L.,University of Maryland University College | Fagan W.F.,University of Maryland University College | DeFries R.,Columbia University | Raboy B.E.,Smithsonian Conservation Biology Institute | Raboy B.E.,Institute Estudos Socioambientais do Sul da Bahia
Tropical Conservation Science | Year: 2010

As habitat for the golden-headed lion tamarin (GHLT; Leontopithecus chrysomelas) in Brazil's Atlantic forest becomes smaller and more fragmented, remaining large forest patches may be critical to the persistence of the species. The objectives of our study were to identify the forest patch size that could support a viable population of GHLTs under a range of risk scenarios and to locate patches meeting these size requirements. We found the self-sustaining minimum viable population (MVP) size of GHLTs using the simulation program Vortex under a baseline model and under several anthropogenic disturbance models. We multiplied the MVP size determined in each model scenario by low, medium, and high GHLT population densities to estimate a minimum area requirement. We then used a forest cover map derived through a supervised classification of 2004-2008 Landsat 5TM imagery to locate forest patches meeting the range of minimum area requirements. We found that the MVP size of GHLTs is 70-960 individuals, requiring a forest patch size of 700-18,113 ha depending on the risk level or scenario considered. We found one forest patch that could support a genetically viable, self-sustaining population of GHLTs under the highest level of risk. However, only one federally protected reserve known to currently support GHLTs exists within the range of the species while continuing deforestation, land conversion, and construction projects are real and major threats to the remaining GHLT habitat. Research into the quality and occupancy of the largest patches highlighted here as well as additional protection of habitat needs to be a priority for GHLT conservation. © Zeigler, Sara L., William F. Fagan, Ruth DeFries, and Becky E. Raboy.


Zeigler S.L.,University of Maryland University College | De Vleeschouwer K.M.,Center for Research and Conservation | De Vleeschouwer K.M.,Institute Estudos Socioambientais do Sul da Bahia | Raboy B.E.,Center for Research and Conservation | And 2 more authors.
Biotropica | Year: 2013

Golden-headed lion tamarins (GHLTs; Leontopithecus chrysomelas) are endangered primates endemic to the Brazilian Atlantic Forest, where loss of forest and its connectivity threaten species survival. Understanding the role of habitat availability and configuration on population declines is critical for guiding proactive conservation for this, and other, endangered species. We conducted population viability analysis to assess vulnerability of ten GHLT metapopulations to habitat loss and small population size. Seven metapopulations had a low risk of extirpation (or local extinction) over the next 100 years assuming no further forest loss, and even small populations could persist with immediate protection. Three metapopulations had a moderate/high risk of extirpation, suggesting extinction debt may be evident in parts of the species' range. When deforestation was assumed to continue at current rates, extirpation risk significantly increased while abundance and genetic diversity decreased for all metapopulations. Extirpation risk was significantly negatively correlated with the size of the largest patch available to metapopulations, underscoring the importance of large habitat patches for species persistence. Finally, we conducted sensitivity analysis using logistic regression, and our results showed that local extinction risk was sensitive to percentage of females breeding, adult female mortality, and dispersal rate and survival; conservation or research programs that target these aspects of the species' biology/ecology could have a disproportionately important impact on species survival. We stress that efforts to protect populations and tracts of habitat of sufficient size throughout the species' distribution will be important in the near-term to protect the species from continuing decline and extinction. © 2013 by The Association for Tropical Biology and Conservation.

Loading Institute Estudos Socioambientais do Sul da Bahia collaborators
Loading Institute Estudos Socioambientais do Sul da Bahia collaborators