Can landscape and species characteristics predict primate presence in forest fragments in the Brazilian Amazon? (original) (raw)
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Habitat partitioning among primates in Maraca island, Roraima, northern Brazilian Amazonia
International Journal of Primatology, 1997
I studied a primate community on a tropical rainforest island, in the northernmost area of the Brazilian Amazonia. While walking through six distinct habitats along a 12-km trail, running toward the center of the island-a remote undisturbed area-I collected data on the use of the different forest types and forest strata by the primate community and the formation of either mixed groups or species assemblages. Five species are present: Cebus olivaceus, C. apella, Saimiri sciureus, Ateles belzubuth, and Alouatta seniculus. They seemed to be habitat generalists, using most habitat types. The five species used the higher strata more significantly, probably because Maraca does not present well-defined forest floors, which could be a result of being located in the transition between the great areas of savannah and the Amazonian seasonally dry forests. The five species all formed some polyspecific associations, which involved sharing the available food resource. Mixed groups were significantly more frequent and therefore possibly more important to Saimiri, which was not the case in relation to the other four species. Assemblages, defined as the presence in the same clumped resource, without coordinated activity, of < 3 primate species, were recorded primarily in fruiting fig trees. I suggest that assemblages are impelled by food constraints, forcing cofeeding in large seasonal resources, highlighting the ecological importance of figs to these primates. Linear regression models show that the number of 132 Mendes Pontes feeding bouts in each habitat type is positively related to the number of fruiting trees exploited, but the density of these fruit trees, diversity of plant species, tree height, and total basal area of each habitat type have no relationship to feeding.
Primate species richness in relation to habitat structure in Amazonian rainforest fragments
Biological Conservation, 1989
Factors affecting species richness in fragmented habitat are often of interest to conservation programs. Groups o fred howler monkeys Alouatta seniculus, white-faced sakis Pithecia pithecia and golden-handed tamarins Saguinus midas occurred in five small (approx. lOha)i fragments of Amazonian rainforest. However, not all of these species occurred in every fragment. The purpose of this study was to identify some of the factors affecting the number and distribution of primate species among these areas. To determine whether habitat structural diversity influenced primate species richness, height, diameter at breast height (DBH) and number of trees, DBH and number of lianas (woody vines) as well as height and number of palms in 15 20 × 20 m quadrats in each fragment were recorded. Also, height and number of secondary growth plants surrounding reserves were sampled. Structurally 'complex' reserves had high mean number of trees, high mean number of lianas, low mean percentage large trees (> 10 cm DBH) per quadrat, and streams. These characteristics were correlated with high species richness. P. pithecia occurred in the most structurally 'complex'fragments, S. midas in fragments surrounded by relatively tall secondary growth and A. seniculus in all five fragments. The relationships between the habitat requirements of the three species and their occurrence in these fragments are discussed.
Primate populations in continuous forest and forest fragments in Central Amazonia
Acta Amazonica, 1988
Population densities of six primate species (Saguinus midas, Pithecia pithecia, Cebus apella, Chiropotes satanas, Alouatta seniculus and Ateles paniscus) were estimated in continuous forest and in isolated reserves (one of 100 ha and four of 10 ha). Saguinusdensities in the continuous forest were found to be low, probably due to the lack of edge habitat and second growth favoured by them; Pithecia, Cebus and Ateles populations are also low, possibly because of more widely distributed and/or less abundant food sources than is true for other Amazonian regions, although hunting in the past, particularly of Ateles may also be a contributing factor; and Chiropotes and Alouatta densities were found to be similar to those observed in other areas of Amazonas forests. Ateles and Chiropotes, which occupy ranges on the order of three km2 were excluded from the 100-ka reserve at the time of its isolation. Unfortunately populations were not known prior to isolation of this reserve but during iso...
Biological Conservation, 2005
Habitat fragmentation has been shown to influence the abundance, movements and persistence of many species. Here, we examine the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of local extinction of five primate and 14 carnivore species within 129 forest patches in a highly fragmented forest landscape of southern Brazilian Amazonia. Classic habitat area effects were the strongest predictors of species persistence, explaining between 42% and 55% of the overall variation in primate and carnivore species richness. Logistic regression models showed that anthropogenic disturbance, including surface wildfires, timber extraction and hunting pressure, had detrimental effects on the persistence of some species over and above those of fragment size. Different species ranged in their responses from highly sensitive to highly tolerant to forest fragmentation. Patterns of local extinction documented here were by no means chance events, and the nestedness of the overall species-by-site matrix was highly nonrandom in terms of the sets of species extirpated from the most to the least species-rich forest patches.
International Journal of Primatology, 2010
Habitat structure and anthropogenic disturbance are known to affect primate diversity and abundance. However, researchers have focused on lowland rain forests, whereas endangered deciduous forests have been neglected. We aimed to investigate the relationships between primate diversity and abundance and habitat parameters in 10 deciduous forest fragments southeast of Santa Cruz, Bolivia. We obtained primate data via line-transect surveys and visual and acoustic observations. In addition, we assessed the vegetation structure (canopy height, understory density), size, isolation time, and surrounding forest area of the fragments. We interpreted our results in the context of the historical distribution data for primates in the area before fragmentation and interviews with local people. We detected 5 of the 8 historically observed primate species: Alouatta caraya, Aotus azarae boliviensis, Callithrix melanura, Callicebus donacophilus, and Cebus libidinosus juruanus. Total species number and detection rates decreased with understory density. Detection rates also negatively correlated with forest areas in the surroundings of a fragment, which may be due to variables Int J Primatol not assessed, i.e., fragment shape, distance to nearest town. Observations for Alouatta and Aotus were too few to conduct further statistics. Cebus and Callicebus were present in 90% and 70% of the sites, respectively, and their density did not correlate with any of the habitat variables assessed, signaling high ecological plasticity and adaptability to anthropogenic impact in these species. Detections of Callithrix were higher in areas with low forest strata. Our study provides baseline data for future fragmentation studies in Neotropical dry deciduous forests and sets a base for specific conservation measures.
Population density of primates in a large fragment of the Brazilian atlantic rainforest
2001
We performed a line transect survey (352.4 km) of primates in the Serra de Paranapiacaba, at one of the largest relatively undisturbed fragments of the Atlantic rainforest of Southeastern Brazil (ca. 1400 km 2 ), in August 1998. The brown capuchin, Cebus apella nigritus, was the most common species found in the area (20 groups, density estimate: 5.31 ± 2.05 individuals per km 2 , mean ± SE). Nine groups of the brown howler monkey, Alouatta guariba clamitans, and eight of the woolly spider monkey, Brachyteles arachnoides arachnoides, were also recorded, with preliminary density estimates of 0.79 ± 0.40 and 2.33 ± 1.37 individuals per km 2 , respectively. Density estimates for these species in other fragments of Atlantic rainforest are reviewed, showing that densities in Paranapiacaba are among the lowest reported. It is suggested that the higher densities reported for isolated populations in small forest patches (<50 km 2 ) is related to the absence of main primate predators, the density compensation phenomenon and the ecological plasticity of some primate species. In contrast, local extinction in many small patches is probably related to hunting pressure. Given the important primate populations found in the Paranapiacaba fragment, conservation strategies for the studied species should give priority to effective protection of the largest remnant fragments from illegal hunting and deforestation, rather than translocation of individuals or captive breeding programs to introduce monkeys in small forest fragments vulnerable to hunting and of uncertain future.
Acta Scientiarum. Biological Sciences, 2020
Human activities result in the formation of a mosaic of forest patches within a non-habitat matrix. The response of the local biodiversity to changes in land-use may occur at different scales. It is important to evaluate the effects of the attributes of both the patches and the surrounding landscape on the occupancy of forest patches by animal populations. Here, we assessed the predictive potential of local (basal area, tree density), patch (size, shape) and landscape scale (total area of forest, number of patches, matrix permeability, patch proximity) variables on the occupancy of forest patches by the syntopic primates Alouatta caraya, Sapajus libidinosus and Callithrix penicillata in the city of Goiânia in the Cerrado region of central Brazil. We used playback to survey primate populations in 22 focal patches and assessed the landscape within a 1000 m buffer zone around each site. In A. caraya, occupancy was influenced by the shape of the focal patches, the amount of forest and f...
Oryx, 1995
Reduced to a tiny fraction of its original area, much of the Atlantic Forest habitat remaining in eastern Brazil is distributed in small, isolated patches on private land. The potential role of these fragments in the conservation of the region's primate fauna is poorly understood. As part of a study of buffy-headed marmosets Callithrix flavicepsin Minas Gerais, forest remnants were visited in order to evaluate this potential. Marmosets were observed in one-third of the sites and may exist in up to 60 per cent of forest patches in the region. A second threatened primate, the brown howler monkeyAlouatta fusca,may occur in one-quarter of the sites visited. The muriquiBrachyteles arachnoideswas not encountered. Overall, the survey suggests that, with appropriate management, privately owned forest fragments may play an increasingly important role in the conservation of the Atlantic Forest's fauna in this and other regions.