|Scientific Name:||Callicebus olallae|
|Species Authority:||Lönnberg, 1939|
|Taxonomic Notes:||Kobayashi and Langguth (1999) and van Roosmalen et al. (2002) recognize five species groups – cupreus, donacophilus, moloch, personatus and torquatus. van Roosmalen et al. (2002) place Callicebus olallae in the donacophilus group, along with: Callicebus donacophilus, Callicebus pallescens, Callicebus oenanthe and Callicebus modestus. Tarifa (1996), Anderson (1997) and Felton et al. (2006) suggest that the taxonomic distinctiveness between C. olallae and Callicebus modestus requires further investigation. However, more recent field observations (Martinez and Wallace 2007) and opportunistically collected specimens (R. Wallace pers. comm.) support the taxonomic separation of C. olallae and C. modestus. Preliminary results from a scat-based genetic study show that both are clearly distinct from C. donacophilus, and from each other (Barreta pers. comm. to R. Wallace).|
|Red List Category & Criteria:||Endangered B1ab(ii,iii,v) ver 3.1|
|Assessor(s):||Veiga, L.M., Wallace, R.B. & Martinez, J.|
|Reviewer(s):||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
This species is listed as Endangered because of its extremely restricted range (400 km²) in a region subject to ongoing forest loss, fragmentation and hunting pressure, all of which are likely to increase with the improvement of a regional highway. The species does not occur in any protected areas.
|Previously published Red List assessments:||
|Range Description:||This species is endemic to Bolivia with very restricted range estimated to be 400 km² (Martinez and Wallace 2007). Recent surveys have revealed that C. olallae is apparently confined to gallery forest and adjacent forest islands of the Yacuma River, with just one other locality in gallery forest of the Manique River (Martinez and Wallace 2007), both in south-western Beni Department. In contrast to the geographic distribution proposed by van Roosmalen et al. (2002), Felton et al. (2006) argue that the species only occurs to the east of the Río Beni. Extensive surveys in the region have since confirmed this to be the case (Martinez and Wallace 2007). The geographical range of Callicebus olallae overlaps with Callicebus modestus, although transitional zones between the two taxa have yet to be confirmed and each seems to specialize on different habitat types (Felton et al. 2006; Martinez and Wallace 2007). Found below 400 m a.s.l.|
Native:Bolivia, Plurinational States of
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The species was formerly only known from the type locality (La Laguna, 5 km from Santa Rosa, [upper río] Beni, Bolivia, altitude about 200 m; Patterson 1992, Tarifa 1996; Anderson 1997). In 2002, Felton et al. (2006) conducted titi monkey surveys and interviewed local residents at four locations: Puerto Santa Cruz on the Río Yacuma; the type locality of La Laguna; Petaca; and Naranjal. Titis were relatively abundant in Naranjal, not encountered in Petaca (although local residents claim they occur there), and are no longer present in La Laguna (probably exterminated through hunting). Examination of holotypes indicates that groups encountered in Rio Yacuma were C. olallae, while two of three groups found in Naranjal were Callicebus modestus (the third appeared to combine characters from both species).
Lopez-Strauss (2007) estimated density for both C. olallae and C. modestuss using calling behavior and an adapted point-count methodology. C. olallae presented conservative density estimates of between 1.8 and 11.5 groups per km² (Lopez-Strauss 2007).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This taxon occurs in relatively dry forest patches within a forest-savanna mosaic, apparently restricted to gallery forest and immediately adjacent forest islands (Lonnberg 1939; Anderson 1997; Felton et al. 2006; Martinez and Wallace 2007).
Titis are frugivores, monogamous primates that generally live in small family groups. Three groups, each with two members, were encountered at Puerto Santa Cruz, to the north of the Rio Yacuma. Aggressive displays were directed towards the researchers. Martinez and Wallace (2007) and Lopez-Strauss (2007) details average group sizes of 2.7 and 2 individuals respectively.
There is some forest loss and habitat fragmentation within its range. Groups surveyed by Felton et al. (2006) occurred in fragments surrounded by cattle ranches. A farmer in Naranjal reported seeing groups crossing grassland gaps (300–400 m) between patches of forest (Felton et al. 2006) and this behaviour has since been confirmed (J. Martinez and Lopez pers. comm.). Uncontrolled grassland fires are also a major threat especially if they jump to forest patches (J. Martinez pers. comm.). Critically, the proposed major improvement to a regional road will exacerbate deforestation and is likely to increase hunting pressure (Felton et al. 2006).
The disappearance of the species from the type locality - La Laguna - indicates that they may be threatened locally by hunting (Felton et al. 2006). They are used as bait for fishing and cat hunting and some are captured for pets. Apparently the presence of sympatric primates such as Saimiri may also be a threat to C. olallae (J. Martinez pers. comm.).
The species does not occur in any protected areas. It is listed on CITES Appendix II.
Conservation programmes in the region include: the Greater Madidi Landscape Conservation Program in northern La Paz and south-western Beni Departments and Kaa-Iya Landscape Conservation Program in Santa Cruz Department of the Wildlife Conservation Society and the Asociación Boliviana para la Conservación and Conservation International in the south-western Beni Department.
Anderson, S. 1997. Mammals of Bolivia: Taxonomy and distribution. Bulletin of the American Museum of Natural History 231: 1–652.
Brown, A. D. and Rumiz, D. I. 1986. Distribucion de los primates en Bolivia. In: M. T. de Mello (ed.), A Primatologia no Brasil, pp. 335-363. Sociedade Brasileira de Primatologia, Brasília, Brazil.
Felton, A., Felton, A. M., Wallace, R. B. and Gómez, H. 2006. Identification, distribution and behavioural observations of the titi monkeys Callicebus modestus Lönnberg 1939, and Callicebus olallae Lönnberg 1939. Primate Conservation 20: 40-46.
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Hershkovitz, P. 1988. Origin, speciation, and distribution of South American titi monkeys, genus Callicebus (Family Cebidae, Platyrrhini). Proceedings of the Academy of Natural Sciences of Philadelphia 140(1): 240-272.
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Kobayashi, S and Langguth, A. 1999. A new species of titi monkeys, Callicebus Thomas, from north-eastern Brazil (Primates, Cebidae). Revista Brasileira de Zoologia 16(2): 531-551.
Lönnberg, E. 1939. Notes on some members of the genus Callicebus. Arkiv för Zoologi 31(A): 1-18.
Lopez, L. In prep.. Dieta y comportamiento alimenticio de dos grupos de Callicebus olallae en la estancia ganadera La Asunta, Beni, Bolivia. Undergraduate Thesis, Universidad Mayor de San Andrés.
Lopez-Strauss, H. In prep.. Estimación de Densidad y Composición de Grupos de dos primates, Callicebus olallae y Callicebus modestus, especies endémicas del sud-oeste del Departamento del Beni – Bolivia. Undergraduate Thesis, Universidad Mayor de San Andrés.
Martinez, J. and Wallace R. B. 2007. Further Notes on the Distribution of the Bolivian Endemic Titi Monkeys, Callicebus modestus and Callicebus olallae. Neotropical Primates 14(2): 47-54.
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Salazar-Bravo, J. A., Tarifa, T., Aguirre, L. F., Yensen, E. and Yates, T. L. 2003. Revised Checklist of Bolivian Mammals. Occasional Papers, Museum of Texas Tech University 220: 1-28.
Tarifa, T. 1996. Mamiferos. In: P. Ergueta and C. de Morales (eds), Libro rojo de los vertebrados de Bolivia, pp. 165-262. Centro de Datos para la conservacion-Bolivia, La Paz, Bolivia.
Van Roosmalen, M. G. M., Van Roosmalen, T. and Mittermeier, R.A. 2002. A taxonomic review of the titi monkeys, genus Callicebus Thomas, 1903, with the description of two new species, Callicebus bernhardi and Callicebus stephennashi, from Brazilian Amazonia. Neotropical Primates 10: 1-52.
Wallace, R. B. and Mercado, N. 2007. La diversidad, distribución y abundancia de primates en Bolivia: Recomendaciones preliminares para su conservación. Abstract and Presentation at the V National Biology Congress. Santa Cruz, Bolivia.
Young, B. E. 2007. Endemic species distributions on the east slope of the Andes in Peru and Bolivia. NatureServe, Arlington, Virginia, USA.
|Citation:||Veiga, L.M., Wallace, R.B. & Martinez, J. 2008. Callicebus olallae. The IUCN Red List of Threatened Species 2008: e.T3554A9939925. . Downloaded on 06 May 2016.|