Introduction
The first records of the primate fauna in the Tapajós-Xingu interfluvium date from the beginning of the 20th century. Snethlage (1912) listed Chiropotes albinasus and Ateles marginatus as the most conspicuous species of the region, and also cited the presence of Saimiri sciureus, Cebus sp., Callicebus sp. and Alouatta sp. Almost a century later, this region remains poorly studied, and our knowledge of the local primate species and their distribution is still incomplete. This paper updates the list of primate species in the Tapajós-Xingu interfluvium, and adds new records for the southern part of this region. We emphasize the need to conserve the primate fauna of this region, as this portion of Amazonia is a target for development projects and is subject to strong pressures from logging and ranching activities.
Methods
We compiled data on the occurrence of primates in the Tapajós-Xingu interfluvium by literature review (Appendix 1), as well as from field observations and by the examination of specimens deposited at the Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ), the Museu Paraense Emílio Goeldi (MPEG) and the Museu de Zoologia da Universidade de São Paulo (MZUSP). We calculated geographic coordinates based on information in catalogues, systematic revisions, faunistic surveys, maps (IBGE, 1972) and gazetteers available on the Internet such as Species Link – Geoloc (CRIA, 2005) and Global Gazetteer 2.1 (FRG, 2004). We plotted the points corresponding to these coordinates (Fig. 1) using the program ArcView 3.3 (ESRI, 2002). The species nomenclature follows Rylands et al. (2000).
Our fieldwork was carried out during two excursions to the region of Serra do Cachimbo, southern Pará State, Brazil. The first excursion was during the rainy season (1–28 March 2004) and the second in the dry season (29 August–17 September 2004). Serra do Cachimbo is located in a transitional zone between the biomes of Amazonia and the Cerrado; from this complex arise several tributaries of the Rios Xingu and Tapajós. The landscape is dominated by a mosaic of vegetation types, including cerrado formations, white sand vegetation, and typical Amazonian forest formations such as terra firme forests and igapó (Lleras and Kirkbride Jr., 1978).
FEP made direct observations of six primate species at Serra do Cachimbo, following existing trails through all the vegetation types in the study area. Those species directly observed included Mico emiliae, Callicebus moloch, Cebus apella, Chiropotes albinasus, Alouatta belzebul discolor and Ateles marginatus. FEP also collected specimens which were later deposited in the MPEG mammal collection (MPEG 37806–37811). We identified the species we collected and observed using illustrations and diagnostic characters described in the literature (Kellogg and Goldman, 1944; Hershkovitz, 1977, 1985, 1990; Jones and Anderson, 1978; Vivo, 1991; Auricchio, 1995; Gregorin, 1996; Emmons and Feer, 1997; Van Roosmalen et al., 1998, 2002; Silva Júnior, 2001), as well as by direct comparison with museum specimens.
Results and Discussion
The majority of the records for primates in the Tapajós-Xingu interfluvium are restricted to the regions close to the lower Rio Tapajós and to the Rio Amazonas. By contrast, there is virtually no information available on the primate fauna in the central regions of the interfluvium.
We compiled a total of 45 localities in the Tapajós-Xingu interfluvium where primates have been recorded, confirming the presence of 13 taxa in this region (Table 1). Five of these taxa (Cebus apella, Callicebus moloch, Chiropotes albinasus, Ateles marginatus and Alouatta belzebul discolor) have wide distributions in this region. Of the others, Cebus albifrons and Mico leucippe have been recorded only from the east bank of the Rio Tapajós; Aotus azarae infulatus and Mico argentatus from the north of the interfluvium, Saimiri ustus from the north-central portion, Saimiri sciureus from the central region, Mico emiliae only from the southern portion and Alouatta seniculus from the south-central area.
Table 1.
Species recorded from the Tapajós-Xingu interfluvium with their known localities of occurrence. The numbers follow the localities in Fig. 1.
Species distribution in the Tapajós-Xingu interfluvium
The distribution of A. marginatus, as defined by Kellogg and Goldman (1944), includes the forests of the south bank of the Amazon River between the Rios Tapajós and Tocantins, in the Brazilian state of Pará. However, although Kellogg and Goldman (1944) designated its type locality as Cametá — on the west bank of the lower Rio Tocantins — no specimen has been observed in the Tocantins-Xingu interfluvium since then, despite many surveys of the mammals of the region. Its historical occurrence in this region is doubtful at best, and the given type locality is almost certainly incorrect (Martins et al., 1988). Thus, this species is effectively known only from the Tapajós-Xingu interfluvium. The southernmost records are restricted to Snethlage's observations from 1912. Our observations in Serra do Cachimbo agree with the hypothesis of Martins et al. (1988), who gave the Rio Teles Pires as the southern limit of A. marginatus.
The distribution of Chiropotes albinasus is restricted to the south of the Amazon River, from the west bank of the Rio Xingu-Irirí to the Rio Madeira (Hershkovitz, 1985). In the Tapajós-Xingu interfluvium, the most southerly records for this species are given by Hershkovitz (1985) and in this paper.
According to Gregorin (1996), A. belzebul discolor (sensu Rylands et al., 2000) is distributed to the south of the Amazon River, from the east bank of the Rio Tapajós to the lower Rio Tocantins and the island of Mexiana. The southernmost records of this species' distribution include our observations (Fig. 1, loc. 36) and those given by Pinto and Setz (2000) for the west bank of the Rio Santa Helena, a tributary of the Rio Teles Pires (Fig. 1, loc. 33). Pinto and Setz (2000) also recorded A. seniculus in the same locality — the only record for this species in the Tapajós-Xingu interfluvium.
Callicebus moloch is distributed between the Rios Araguaia-Tocantins and Tapajós (Hershkovitz, 1990; Van Roosmalen et al., 2002), limited in the south to the region between the headwaters of the Rios Xingu and Juruena (Fig. 1, loc. 32 and loc. 35).
The three species of Mico found in the interfluvium have distributions which are restricted or poorly understood. Mico leucippe seems to be endemic, with records only in the Tapajós-Cupari interfluvium (Ávila-Pires, 1969, 1986; Napier, 1976; Hershkovitz, 1977; Branch, 1983; Vivo, 1985; George et al., 1988; Alperin, 1993). Mico argentatus is recorded from the north (Fig. 1, Table 1), restricted to the lower courses of the Rios Tapajós and Tocantins (Ferrari and Lopes, 1990). Hershkovitz (1977) extended its distribution to include the Curuá-Irirí interfluvium, as he considered Mico emiliae to be a synonym of M. argentatus. M. emiliae has a relatively wide distribution, apparently including the Brazilian states of Amazonas, Mato Grosso, Pará and Rondônia (Vivo, 1985, 1991; Ávila-Pires, 1986; Ferrari and Lopes, 1992; Alperin, 1993; Roosmalen et al., 2000). However, the details of this distribution are still not well understood, because of its apparent discontinuity. Rylands et al. (1993) suggest that the form of M. emiliae recorded in Rondônia (Vivo, 1985, 1991) is distinct from that described by Thomas (1904) in the Tapajós-Xingu interfluvium. This was corroborated by Sena (1998) and Ferrari et al. (1999), who demonstrated that the form of emiliae found in the Tapajós-Xingu interfluvium is more similar in every way to M. argentatus than to the form of “emiliae” found in Rondônia. Until now, M. emiliae had not been proven to occur in the region of Serra do Cachimbo. Our observation provides a significant range extension of M. emiliae to the southwest, to at least the right bank of the Rio Teles Pires.
The possible presence of Cebus albifrons in the Tapajós-Xingu interfluvium is controversial. There is only one record from the region, on the lower Tapajós (Napier, 1976), which we believe to be valid; but more observations will be required to determine whether C. albifrons is widespread in the interfluvium.
The records of Saimiri sciureus in this area are restricted to the middle and lower Tapajós (Ayres and Milton, 1981; Thorington, 1985; George et al., 1988; Silva Júnior, 1992; Vaz, 2001). The only record of this species beyond the right bank of the Rio Tapajós is that of Snethlage (1912) from the Jamanxim-Curuá interfluvium. In the area of the Rio Xingu, this species has only been recorded from the east bank (Voss and Emmons, 1996). Almost all the records of Saimiri ustus are from the middle and lower Rio Tapajós, but one record (Martins et al., 1988) is from outside of this region (Fig. 1, loc. 42).
Recorded localities for Aotus azarae infulatus extend from the Rios Tapajós and Juruena (Pieczarka et al., 1993) to the Rio Paraguai in the south of Mato Grosso (Ford, 1994), and throughout the reach of the Rio Tocantins (Schneider et al., 1989). This taxon is known only from the northern portion of the Tapajós-Xingu interfluvium (Vieira, 1955; Branch, 1983; Martins et al., 1988; Vaz, 2001).
Threats to the primates of the Tapajós-Xingu interfluvium
Ateles marginatus is listed as Endangered by the IUCN Red List (IUCN, 2003) due to hunting pressure and environmental degradation in the Tapajós-Xingu interfluvium. This is due mainly to the exploitation of the region along the Transamazônica (BR-230) and Cuiabá-Santarém (BR-163) highways, primarily from logging and ranching. Furthermore, its restricted distribution — as well as those of M. emiliae and M. leucippe — is a contributing factor to threats to these species.
Acknowledgments
Part of this research was financed by grants from the Ministério do Meio Ambiente through the PROBIO project. The authors wish to thank the staff of the Museu Paraense Emílio Goeldi (MPEG), the Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ), and the Museu de Zoologia da Universidade de São Paulo (MZUSP). The authors would also like to thank Mike Hopkins for his helpful comments on this manuscript.
References
Notes
[1] Flá Eduardo Pimenta and José de Souza e Silva Júnior, Setor de Mastozoologia, Coordenação de Zoologia, Museu Paraense Emílio Goeldi, Belém, Pará, Brazil. E-mail: <flavioedupimenta@ig.com.br>.
Appendices
Appendix I.
Gazetteer of catalogs, systematic reviews and inventories from the Tapajós-Xingu interfluvium, and localities obtained from analysis of specimens deposited in scientific collections. The numbers follow those in Figure 1.