Antonio Rossano Mendes Pontes

Sleeping sites of common marmosets (Callithrix jacchus) in defaunated urban forest fragments: a strategy to maximize food intake

The purpose of this study was to investigate if there was any species-specific type and structure of sleeping sites of common marmosets Callithrix jacchus and their key determinant. The study was conducted in an urban fragment of the Atlantic forest of north-eastern Brazil, where a group of common marmosets was followed for 488 h. For this purpose we used ad lib observations, performed twice a week, when the animals were entering and leaving the sleeping sites, identified potential predators of the common marmosets through interviews with local people, and identified the trees that provided them with fruit and/or exudate during the study. Five sleeping sites were identified, all invariably in the border of the native forest and the orchard. No predators of common marmosets were seen by local people or recorded during this study, and the sleeping trees were located invariably in the place where there was the highest concentration of feeding trees, regardless of its structure. There was no species-specific type and structure of sleeping places of common marmosets. The key variable defining the choice of a sleeping place was the availability and location of immediate sources of food.

Polygyny and Infanticide in Common Marmosets in a Fragment of the Atlantic Forest of Brazil

Common marmosets (Callithrix jacchus) had been regarded as a monogamous species [1, 2], since reproductive activity in subordinate animals was suppressed in the presence of the alpha pair [3]. Studies in the wild, however, have shown that more than one female [4–8] or more than one male [9] could mate, in some cases, conceive and, in some other cases, rear litters. This flexibility has also been shown in captivity [10], and among other species of Callitrichidae, suggesting that polygyny [11], polyandry [12] or polygynandry [13] is widespread. Hrdy [14] shows that infanticide is present in different classes of animals and that the ways in which infanticidal individuals benefit varies widely. Resource competition, which can vary from food resources to physical characteristics of the environment [14] to having potential helpers within the group [15], is discussed.

The small mammals of the highly impacted North-eastern Atlantic Forest of Brazil, Pernambuco Endemism Center

The Atlantic forest of Brazil is nowadays reduced to less than 8% of its total original area and yet many species remain to be described. The Atlantic Forest north to the Sao Francisco river - The Pernambuco Endemism Center (CEPE) - has less than 2% of its original forest cover and yet the knowledge on small mammals is scarce. Aiming to assess the small mammal community of this region surveys were carried out in 12 forest fragments of different sizes in distinct geographic areas of the CEPE. The capture-mark-recapture technique was used with live-traps set along linear transects. We recorded 15 species, two of which are in the IUCN Red List, but not in the Brazilian List of Threatened Species. The highest richness and abundance indices were recorded in medium- sized fragments and in the rainy season. More marsupial species were recorded compared to rodents. Our results suggest that fragmentation caused the extinction of those most specialized species, currently remaining only those most tolerant to fragmentation and urbanization. It is recommended that urgent measures should be taken to reconnect and restore these fragments to allow recolonization and reestablishment of the gene flow among the populations.

Mass Extinction and the Disappearance of Unknown Mammal Species: Scenario and Perspectives of a Biodiversity Hotspot's Hotspot.

We aimed to determine the conservation status of medium- and large-sized mammals and evaluate the impact of 500 years of forest fragmentation on this group of animals in the Pernambuco Endemism Center, in the biogeographical zone of the Atlantic forest north of the São Francisco River in northeastern Brazil. Line transect surveys were performed in 21 forest fragments, resulting in a checklist of the mammals of the entire Pernambuco Endemism Center area. We ran a generalized linear model (Factorial ANCOVA) to analyze to what extent the vegetation type, fragment area, isolation, sampling effort (as total kilometers walked), or higher-order interactions predicted (a) richness and (b) sighting rates. To determine if the distribution of the species within the forest fragments exhibited a nested pattern, we used the NODF metric. Subsequently, we performed a Binomial Logistic Regression to predict the probability of encountering each species according to fragment size. Out of 38 medium- and large-sized mammal species formerly occurring in the study area, only 53.8% (n = 21) were sighted. No fragment hosted the entire remaining mammal community, and only four species (19%) occurred in very small fragments (73.3% of the remaining forest fragments, with a mean size of 2.8 ha). The mammalian community was highly simplified, with all large mammals being regionally extinct. Neither the species richness nor sighting rate was controlled by the vegetation type, the area of the forest fragments, isolation or any higher-order interaction. Although a highly significant nested subset pattern was detected, it was not related to the ranking of the area of forest fragments or isolation. The probability of the occurrence of a mammal species in a given forest patch varied unpredictably, and the probability of detecting larger species was even observed to decrease with increasing patch size. In an ongoing process of mass extinction, half of the studied mammals have gone extinct. The remaining medium-sized mammal community is highly simplified and homogenized. The persistence of these species in a forest patch is determined by their ability to adapt to a novel simplified diet, the efficient use of the surrounding matrix without being engulfed by the sink effect, and escaping hunting. Our results suggest that the 21st century medium-sized mammalian fauna of this region will comprise only four species unless strict conservation measures are implemented immediately and every forest fragment is effectively protected.

Diversity, abundance and the impact of hunting on large mammals in two contrasting forest sites in northern amazon

A variety of Amazonian mammals serve as sources of food for its human inhabitants, but hunting can have a strong negative impact on them. Diversity, abundance, biomass, and average group size of medium-sized and large mammals are compared across two forest areas of the northern Amazon: the Viruá National Park (protected) and the Novo Paraíso settlement (a human settlement where hunting is permitted). Hunting pressure was also characterized in Novo Paraíso. A total of 33 mammal species were recorded. There were no significant differences in the sighting rates, relative abundance and biomass, and mammal group sizes between the two areas, although the totals of all these variables were higher in Viruá due to the higher abundance of Tayassu pecari, which was not recorded at Novo Paraíso. It is suggested that T. pecari may be on the verge of local extinction, as it was the most hunted species in the settlement area. Through interviews with 50 hunters, we estimate that 541 mammals of 20 species were hunted during the study year, resulting in an estimated biomass take of 8517 kg. While the hunting intensity in Novo Paraíso may be sustainable in the short term, the reported decline of hunting efficiency, combined with the extirpation of T. pecari, suggests that mammal abundance may decline there in the near future. In the study year, 849 hunts were carried out in a hunting effort of 4575 hours, with a maximum distance travelled of 5.4 km. There was an average of 4.82 consumers for each hunt, and a per capita harvest rate of 2.24 individuals/consumer year. Hunting was not only for subsistence, but also for retaliation, although some species may not be hunted due to cultural taboos. The need for quantification of harvesting rates to maintain hunting at sustainable levels is highlighted.

The Simplified Novel Diet of the Highly Threatened Blond Capuchin in the Vanishing Pernambuco Endemism Center

Observations of a group of blond capuchins, isolated in three small forest fragments of the Pernambuco Endemism Center, located in the Atlantic Forest of North-eastern Brazil, revealed that the two most exploited food sources (ca. 50 %) were both introduced to the area, and were available throughout the study period. Out of 33 food sources observed, six introduced plant species were responsible for the bulk of the capuchins’ diet (ca. 60 %). These capuchins exploited a highly restricted diet, the majority of which were introduced resources. They may have only been able to survive in these isolated forest fragments via the exploitation of novel foods, which in the long term may not assure their survival.