Marilyn A. Norconk, PhD

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Research

• Brownsberg Nature Park, Suriname
• Lago Guri, Venezuela
• Graduate Students

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• Education & Academic Positions

Courses Taught

• Human Evolution
• Human Evolution Lab
• Human Behavioral Ecology
• Primate Ecology & Conservation
• Primate Ethology
• Principles of Biological Anthropology

Research Data

• Saki Feeding Ecology
• Saki Nutritional Analysis
• Sexual Dichromatism in White-Faced Sakis
• Brownsberg Nature Park

Kent State University Links

• Department of Anthropology
• Kent State University

Marilyn A. Norconk

Lago Guri, Venezuela

 

The late Warren Kinzey (CUNY) and I surveyed and then developed a field site in Lago Guri, Venezuela for long-term research of saki monkeys (Chiropotes satanas and Pithecia pithecia).  Beginning in 1987, one year after the completion of the Raúl Leoni dam and hydroelectric plant, we established trail systems and began vegetation sampling and primate habituation on three islands. Bearded saki research was conducted on a large island in the southern portion of the lake, on Danto Manchado from 1989-1995. White-faced sakis were encountered on two islands in the northern Las Carolinas region of the lake. A very small island (c. 3 ha) called “Pithecia” island was used initially, but abandoned after 2 years. A long-term study of white-faced sakis continued on Isla Redondo (Round Island) until 2002. During this period, 4 undergraduate students from the US and Venezuela, 10 graduate students from the US, one from Venezuela, and four from the UK or Europe conducted research on plants, sakis, bearded sakis, and howler monkeys. Four undergraduate students from the US and three from Venezuela contributed to saki and howler research.  In all, research at this site resulted in four PhDs, six MA theses, two bachelor theses (Venezuelan students) and two Research Experience for Undergraduate awards (for US students).  Research support was provided by two NSF awards: BNS 87-19800 (to W.G. Kinzey and M.A. Norconk) and SBE 98-07516 (to Norconk), the Wenner Gren Foundation for Anthropology Research (#6138: 1997) (to Norconk), City University of New York Graduate School, and Kent State University, Research and Graduate Studies.

 

Over a period of 13 years, research at Lago Guri provided the longest study of habituated white-faced and bearded sakis to date, with data on intra- and inter-group social behavior, territoriality, feeding strategies, and hormonal correlates of reproductive behavior. With this research, we confirmed that white-faced sakis are not monogamous, but may have two or more breeding females in a social group (now confirmed in free-ranging sakis in Suriname). First age at reproduction is about 5 years for females and interbirth intervals range from 12-36 months. Using fecal samples collected from wild white-faced sakis we confirmed (from captive data) that female reproductive cycles are 17 days in duration and we collected the first data on testosterone and cortisol on wild white-faced sakis. Data collected from sakis on three islands resulted in the first comparative data set on nutrient and deterrent properties of fruit and seeds ingested by bearded sakis and white-faced sakis. I am very grateful to Dr. Mary Ann Raghanti and the late Dr. Susan Shideler for their participation in the hormonal studies.

 

 

Publications

Kinzey, W.G., Norconk, M.A., and Alvarez-Cordero, E. 1988. Primate survey of eastern Bolivar, Venezuela. Primate Conservation 9:66-70. [PDF 2.2MB]

 

Peetz, A., Norconk, M.A., and Kinzey, W.G. 1992. Predation by jaguar on howler monkeys (Alouatta seniculus) in Venezuela. American Journal of Primatology 28:233-228. [PDF 1.7MB]

 

Kinzey, W.G. and Norconk, M.A. 1993. Physical and chemical properties of fruit and seeds eaten by Pithecia and Chiropotes in Surinam and Venezuela. International Journal of Primatology 14(2):207-227. [PDF 3.42MB]

 

Norconk, M.A. 1996. Seasonal variation in the diets of white-faced and bearded sakis (Pithecia pithecia and Chiropotes satanas) in Guri Lake, Venezuela. In Adaptive Radiations of Neotropical Primates. M.A. Norconk, A.L.Rosenberger, P.A. Garber (eds.). New York: Plenum. Pp. 403-423. [PDF 4.69MB]

 

Rosenberger, A.L., Norconk, M.A., Garber, P.A. 1996. New Perspectives on the Pitheciines. In Adaptive Radiations of Neotropical Primates. M.A. Norconk, A.L.Rosenberger, P.A. Garber (eds.). New York: Plenum. Pp. 403-423. [PDF 1.3MB]

 

Aymard, G., Norconk, M., Kinzey, W. 1997. Composición florística de comunidades vegetales en islas en el Embalse de Guri, Río Caroní, Estado Bolívar, Venezuela. BioLlania Esp. 6:195-233. [PDF Scan 15.8MB; OCR 409KB]

 

Norconk, M.A., Wertis, C.A., Kinzey, W.G. 1997. Seed predation by monkeys and macaws in eastern Venezuela: preliminary findings. Primates 38(2):177-184. [PDF 2.3MB]

 

Norconk, M.A., Grafton, B.W., and Conklin-Brittain, N.L. 1998. Seed dispersal by neotropical seed predators. American Journal of Primatology 45:103-126. [PDF 269 KB]

 

Gleason, T.M., Norconk, M.A. 2002. Predation risk and anti-predator adaptations in white-faced sakis, Pithecia pithecia. In Eat or Be Eaten: Predation-Sensitive Foraging in Primates. L. Miller (ed). Cambridge University Press. Pp. 169-184. [PDF 2.6MB]

 

Norconk, M.A., Grafton, B.W. 2003. Changes in forest composition and potential feeding tree availability on a small land-bridge island in Lago Guri, Venezuela. In Primates in Fragments: Ecology and Conservation. L.K. Marsh (ed). Kluwer/Plenum Press. Pp: 211-228. [PDF 441KB]

 

Norconk, M.A. Conklin-Brittain, N.L. 2004. Variation on frugivory: the diet of venezuelan white-faced sakis (Pithecia pithecia). International Journal of Primatology 25(1):1-25. [PDF 385KB]

 

Norconk, M.A. 2006. Long-term study of group dynamics and female reproduction in Venezuelan Pithecia pithecia. International Journal of Primatology 27:653-674. [PDF: print 2.23MB | web 667KB]

 

 

Research by undergraduate students:  [Also see graduate student page]

Natalia Ceballos – Comportamiento social de una tropa de mono viudo Pithecia pithecia (Cebidae: Primates) en una isla del Embase de Guri (Estado Bolívar). (Licenciado en Biología, Universidad Central de Caracas, Venezuela – 1996)

 

Karla M. Funk (KSU) The spatial and contextual nature of saki trills (Pithecia pithecia) in Lago Guri, Venezuela. (REU recipient – 1999)

 

Terrence M. Gleason (KSU) 2002. Predation risk and anti-predator adaptations in white-faced sakis, Pithecia pithecia. In Eat or Be Eaten: Predation-Sensitive Foraging in Primates. L. Miller (ed). Cambridge University Press. Pp. 169-184. (REU recipient 1993)

 

Ricardo D. Lopez (UCSD) Preliminary vocal repertoire of wild bearded sakis (Chiropotes satanas) in eastern Venezuela. (REU recipient 1991)

 

Mailén Ramirez C. – Dieta y comportamiento alimentario de una tropa de Pithecia pithecia (mono saki cara blanca), en una isla del Embalse de Guri, Edo. Bolivar. (Licenciado en Biología, Universidad Central de Caracas, Venezuela – 1996)

 

Bernardo Urbani (Universidad Central de Caracas) 2002. A field observation on color selection by New World sympatric primates, Pithecia pithecia and Alouatta seniculus. Primates 43(2):95-101. [PDF 420KB]

 

Catherine Wertis (UCSD) 1997. Seed predation by monkeys and macaws in eastern Venezuela: preliminary findings. Primates 38(2):177-184. (REU recipient 1991)