José de Sousa e Silva Júnior

Morphology and mitochondrial phylogenetics reveal that the Amazon River separates two eastern squirrel monkey species: Saimiri sciureus and S. collinsi

Saimiri has a complicated taxonomic history, and there is continuing disagreement about the number of valid taxa. Despite these controversies, one point of consensus among morphologists has been that the eastern Amazonian populations of squirrel monkeys form a single terminal taxon, Saimiri sciureus sciureus (Linnaeus, 1758). This group is distributed to both the north and south of the middle to lower Amazon River and in the Marajó Archipelago. However, a recent molecular study by Lavergne and colleagues suggested that the Saimiri sciureus complex (comprised of S. s. sciureus sensu lato, S. s. albigena, S. s. macrodon, and S. s. cassiquiarensis) was paraphyletic. The discordance between morphological and molecular studies prompted us to conduct a new multidisciplinary analysis, employing a combination of morphological, morphometric, and molecular markers. Our results suggest the currently recognized taxon S. s. sciureus contains two distinct species, recognized by the Phylogenetic Species Concept: Saimiri sciureus (Linnaeus, 1758) and Saimiri collinsi Osgood, 1916. East Amazonian squirrel monkeys north of the Amazon have a gray crown (S. sciureus), and south of the Amazon, the crown is yellow (S. collinsi). Morphometric measurements also clearly distinguish between the two species, with the most important contributing factors including width across upper canines for both sexes. For males, the mean zygomatic breadth was significantly wider in S. sciureus compared to S. collinsi, and for females, the width across the upper molars was wider in S. sciureus compared to S. collinsi. Mitochondrial phylogenetic analyses support this separation of the eastern Amazonian squirrel monkeys into two distinct taxa, recovering one clade (S. sciureus) distributed to the north of the Amazon River, from the Negro River and Branco River to the Guiana coast and the Brazilian state of Amapá, and another clade (S. collinsi) south of the Amazon River, from the region of the Tapajós River to the state of Maranhão, as well as within the Marajó Archipelago. The revalidation of the species S. collinsi was corroborated by all of the methods in the study, as the clades recovered in our molecular study are congruent with the pattern of morphological variation. We confirm both the paraphyly of the Saimiri sciureus complex and the paraphyly of the subspecies S. s. sciureus as defined in the current literature.

Diversity, Geographic Distribution and Conservation of Squirrel Monkeys, Saimiri (Primates, Cebidae), in the Floodplain Forests of Central Amazon

Eleven taxa of primates are found in the floodplains of the western portion of the central Brazilian Amazon, protected in part by the Mamirauá Sustainable Development Reserve. The taxonomy of the squirrel monkeys, the number of taxa, and their geographic distributions are still poorly understood. Here we investigate differentiation among the taxa of this genus in Mamirauá, examining their morphology and geographic distribution. We registered 333 points of occurrence of squirrel monkeys and examined 117 specimens deposited in scientific collections. The results of the morphological analyses were generally in good agreement with field observations. Together they indicate the existence of three taxa: Saimiri vanzolinii, Saimiri sciureus macrodon, and S. s. cassiquiarensis. The restricted range of Saimiri vanzolinii in the southeastern portion of the reserve covers an area of 870 km2, and it is among the smallest of the distribution areas for any Neotropical primate species. Saimiri sciureus cassiquiarensis has a disjunct distribution, crossing the Japurá River to the right bank into the reserve in two places, and S. s. macrodon is the squirrel monkey ranging widely in the northwest of Mamirauá. There are three areas of parapatry: one between Saimiri vanzolinii and Saimiri sciureus macrodon and two between S. vanzolinii and S. s. cassiquiarensis. We recommend that anthropogenic changes in the region be monitored, and conservation measures be taken to protect these primates, especially considering the endemism and very restricted range of Saimiri vanzolinii and its consequent vulnerability to extinction.

Non-volant mammalian diversity in fragments in extreme eastern Amazonia

Current deforestation practices are likely to result in fragmentation of much of Amazonia. Extreme eastern Amazonia (here referring to the region east of the Tocantins River) is the most populated area of the Brazilian Amazon and, unfortunately, represents the likely future scenario for remaining Amazonia. Although data are available on mammals in central Amazon fragments (the BDFFP project, http://pdbff.inpa.gov.br/), surprisingly little is known about mammalian distribution and responses to fragmentation in eastern Amazonia. As an initial step towards understanding these responses, we compiled available data on mammalian assemblage composition in four fragments east of the Tocantins River, in northeastern Pará, Brazil, between 2002 and 2006. These fragments are privately owned and embedded within a matrix of secondary forest, pasture, slash-and-burn agriculture, and roads. Survey methods included diurnal line transect censusing, nocturnal censusing, live trapping of small mammals, opportunistic observations, and interviews with local informants. Despite environmental stresses, nearly all of the expected large mammalian fauna was recorded at least once, providing reason for optimism. We documented 58 species of mammals in nine orders, and most species we failed to encounter were small nocturnal taxa for which our sampling effort likely was inadequate. Although preliminary in nature, this study highlights the need for comprehensive faunal surveys and complementary ecological research on the fauna of extreme eastern Amazonia. It also indicates that the terrestrial fauna of the region shows indications of resilience in spite of a long history of exploitation.

New species of titi monkey, genus Callicebus Thomas, 1903 (Primates, Pitheciidae), from Southern Amazonia, Brazil

The genus Callicebus is one of the most diverse Neotropical primate groups, with 31 recognized species. However, large knowledge gaps still exist regarding the diversity of this genus. Such gaps are gradually being filled due to recent intensification of sampling efforts. Several geographic distributions have been better delimited, and six new species have been described in the last 15 years. The goal of the present study is to describe a new species of Callicebus belonging to the Callicebus moloch species group, recently discovered in an area previously considered to be part of the geographic distribution of C. cinerascens. Data collection was conducted through direct observations, specimen collection and interviews with local residents during four expeditions. Specimens were deposited in the mammalian collection of the Museu Paraense Emilio Goeldi.. For a comparative evaluation, we examined specimens of the other species of the Callicebus moloch species group, especially the geographically neighboring forms, C. bernhardi and C. cinerascens. We examined 10 chromatic characters of the fur. In addition to body mass, we verified the conventional external variables and 26 craniometric variables. The new species differs from all other Amazonian Callicebus by an exclusive combination of characters, being easily distinguished by the light gray line of the forehead, dark ocher sideburns and throat, dark gray portions of the torso and flanks, and uniformly orange tail. The geographic distribution of the new species is limited by the Roosevelt and Aripuana rivers, in the states of Mato Grosso and Amazonas, Brazil. Approximately 25% (1,246.382 ha) of this area falls within conservation areas, with five areas of sustainable use (746,818 ha) and three of integral protection (499,564 ha). Furthermore, a considerable portion of the distribution area is located within indigenous lands (1,555.116 ha - 32%). Therefore, 57% (2,801.498 ha) of the occurrence area of the new species falls within protected areas.

A novel method for capturing and monitoring a small neotropical primate, the squirrel monkey (Saimiri collinsi).

Squirrel monkeys (genus Saimiri) are agile, arboreal primates that are seldom captured in the wild due to their small body size (<1 kg) and large, non‐cohesive social groups (40–50 individuals). However, long‐term studies on these primates often require captures and permanent identification of individuals, in order to monitor their behavior and health. Here we report on a novel trapping method successfully used to capture Saimiri collinsi, in Eastern Amazonia, Brazil. Our objective was to capture as many individuals as possible from one social group of approximately 50 individuals, ranging over 150 ha of terra firme forest. Captures occurred in November and December 2013. We habituated animals to feed on a large platform located in a 123.5 m2 area enclosed by a green net (3 m high). Multiple individuals could freely enter and exit the area via four ropes affixed from surrounding trees to the platform. Once individuals were feeding inside the netted area on selected trapping days, the ropes were dropped remotely, eliminating their escape routes. We successfully trapped 21 different individuals of the social group (14 adults and 7 immatures) with this method. We conclude that this is a conceptually simple, effective method for trapping squirrel monkeys in most habitats, and possibly other small arboreal primates that live in large social groups. The present method was more effective than previous methods utilized to capture squirrel monkeys in the field, and has the advantages of: allowing for safe capture of several individuals simultaneously; enabling re‐captures; releasing of animals as a group at the site of capture; use of soft netting which facilitates safe capture of the monkeys. Am. J. Primatol. 77:239–245, 2015.

Primatas da Reserva Particular do Patrimônio Natural Água Boa, Cacoal, Rondônia, Brasil

O conhecimento da fauna de primatas do Estado de Rondônia, o qual está inserido no “arco do desmatamento” (Ferreira et al., 2005), é escasso (Ferrari et al, 1996; van Roosmalen et al., 2002). Segundo van Roosmalen et al. (2002), os fragmentos florestais da região podem abrigar até nove espécies. Neste estudo realizamos um levantamento dos primatas habitantes de um fragmento de floresta de terra firme, a Reserva Particular do Patrimônio Natural Água Boa.

New records of Saimiri collinsi Osgood, 1916 (Cebidae, Primates), with comments on habitat use and conservation

Saimiri collinsi is a primate that occurs in the Amazon biome and recently was elevated to species status. Despite being an abundant and widespread species, S. collinsi distributional limits are still unknown in the transitional region between Amazon and Cerrado biomes. Here we provide 25 new records for the species, obtained through field observation and analysis of museum specimens. Twenty-one records are from Maranhāo state, three from Tocantins where the species had not yet been registered and one in Pará state. These records expand its known distribution, which now includes the area of transition between the Amazon and Cerrado, as well as one record in the Cerrado biome. We registered the species in areas with intense forest fragmentation and within different habitat types, including primary and secondary forest, babassu palm forest and capoeira forest. This indicates that S. collinsi is a species that can survive in locations with extreme anthropogenic alterations. Nevertheless, out of these new records only the ones in Maranhāo are within protected areas. Even these protected areas are undergoing pressures from deforestation, agriculture, livestock and mining, suggesting that these squirrel monkey populations might be threatened in this region.