Nga Nguyen

Dr. Nga NguyenI am a behavioral biologist whose work focuses on the behavior and ecology of wild non-human primates. My research combines behavioral observations of wild non-human primates with non-invasive sampling for information on their genetics, endocrinology, and disease and microbiome ecology to better understand the sources and consequences of variability in primate social behavior across individuals and groups in natural populations. Much of my past and present research focuses on wild populations of monkeys in East Africa, including in Kenya, Rwanda and Ethiopia. By studying primates in natural settings, I can monitor the interactions between behavior, ecology and various biological processes within the selective environment in which these interactions evolved. In addition, non-invasive sampling allows me to both assess potential determinants of behavior and to evaluate potential consequences of behavior without disruptions to the animals’ daily lives. My research aims to shed light on and provide new insights into the processes that underlie social behavior in humans and nonhuman primates.


About Me

Yellow baboon mother and infant at Ambroseli, KenyaI was born in Saigon, Viet Nam in 1976 and immigrated with my family to the US in 1982. I grew up in Brooklyn, NY, attended Midwood High School, and in 2000 earned my Bachelor’s degree at Barnard CollegeOpens in new window , majoring in both Anthropology and Biology. In 2006, I earned my Ph.D. in Ecology and Evolutionary BiologyOpens in new window from Princeton UniversityOpens in new window where I studied under the supervision of Dr. Jeanne AltmannOpens in new window . For my Ph.D., I lived in a tented camp at the base of Mount Kilimanjaro for a year and a half, studying the causes and consequences of variation in mothering behavior in the wild yellow baboons (Papio cynocephalus) at Amboseli, Kenya. The Amboseli population of baboonsOpens in new window has been the subject of intensive research by Dr. Jeanne Altmann and her colleagues for over four decades and much is known about their behavior, ecology, physiology, and population genetics. Before joining the faculty at CSUF, I served as the Director of Cleveland Metroparks Zoo'sOpens in new window Wildlife Endocrinology Laboratory where I oversaw a research program that examined hormone-behavior relationships as a means of enhancing the reproduction and welfare of wildlife living in zoos and in the wild.


Research Interests

Males fightingCurrently, I am investigating the behavior, ecology, and conservation biology of gelada monkeys (Theropithecus gelada) at Guassa, Ethiopia in collaboration with Dr. Peter FashingOpens in new window . Geladas are unique among primates yet surprisingly little is known about them relative to other terrestrial primates like baboons, vervets, and macaques. In addition, my study site – Guassa – is an unusually ecologically pristine alpine grassland in north-central Ethiopia that has been conserved by one of the few surviving ancient indigenous conservation initiatives on the African continent. My current research on geladas at Guassa focuses on (a) female reproductive ecology, (b) intersexual conflict, (c) disease ecology, and (d) gut microbiome health. For more information about my research on geladas visit the Guassa Gelada Research ProjectOpens in new window website and see the recent photoessay on geladas and Guassa in the April 2017 issue of National Geographic magazine. I welcome undergraduate and graduate student participation and collaboration on my research in primate behavioral ecology. 


Teaching Interests

I teach a variety of courses in Evolutionary Anthropology, including Introduction to Biological Anthropology (ANTH 101), Primate Behavior (ANTH 301), and Hormones and Behavior (ANTH/BIOL 456). In addition, as a faculty member in the graduate program in Environmental StudiesOpens in new window , I teach a graduate core course, Environmental Issues and Approaches (ENST 500).



  • Lin, B., Foxfoot, I.R., Miller, C.M., Venkataraman, V.V., Kerby, J.T., Bechtold, E.K., Kellogg, B.S., Nguyen, N., and Fashing, P.J. (2020). Leopard predation on gelada monkeys at Guassa, Ethiopia. American Journal of Primatology 82: e23098. DOI: 10.1002/ajp.23098
  • Tamrat, M., Atickem, A., Tsegaye, D., Nguyen, N., Bekele, A., Evangelista, P., Fashing, P.J., and Stenseth, N.C. (2020). Human-wildlife conflict and coexistence: A case study from Senkele Swayne’s Hartebeest Sanctuary in Ethiopia. Wildlife Biology DOI: 10.2981/wlb.00712
  • Trede, F., Lemkul, A., Atickem, A., Beehner, J., Bergman, T.J., Burke, R., Fashing, P.J., Knauf, S., Mekonnen, A., Moges, A., Nguyen, N., Roos, C., and Zinner, D. (2020). Geographic distribution of microsatellite alleles in geladas (Primates, Cercopithecidae): Evidence for three evolutionary units. Zoologica Scripta DOI: 10.1111/zsc.12451
  • Atickem, A., Stenseth, N.C., Fashing, P.J., Nguyen, N., Chapman, C.A., Bekele, A., Mekonnen, A., Omeja, P., and Kalbitzer, U. (2019). Build science in Africa. Nature 570: 297-300. DOI: 10.1038/d41586-019-01885-1
  • Fashing, P.J., Nguyen, N., Burke, R., Mekonnen, A. & Gippoliti, S. 2019. Theropithecus gelada ssp. gelada. The IUCN Red List of Threatened Species 2019: e.T136849A17982784
  • Fashing, P.J., Nguyen, N., Burke, R., Mekonnen, A. & Gippoliti, S. 2019. Theropithecus gelada ssp. obscurus. The IUCN Red List of Threatened Species 2019: e.T40010A17982810
  • Gippoliti, S., Mekonnen, A., Burke, R., Nguyen, N. & Fashing, P.J. 2019. Theropithecus gelada. The IUCN Red List of Threatened Species 2019: e.T21744A17941908
  • Trosvik P., de Muinck E.J., Rueness E.K., Fashing P.J., Beierschmitt E.C., Callingham K.R., Kraus J.B., Trew T.H., Moges A., Mekonnen A., Venkataraman V.V., Nguyen N. 2018. Multilevel social structure and diet shape the gut microbiota of the gelada monkey, the only grazing primate. Microbiome 6: 84. DOI 10.1186/s40168-018-0468-6
  • Zinner, D., Atickem, A., Beehner, J.C., Bekele, A., Bergman, T.J., Burke, R., Dolotovskaya, S., Fashing, P.J., Gippoliti, Knauf, S., Knauf, Y., Mekonnen, A., Moges, A., Nguyen, N., Stenseth, N.C., and Roos, C. (2018). Phylogeography, mitochondrial DNA diversity, and demographic history of geladas (Theropithecus gelada). PLoS ONE 13(8): e0202303. DOI: 10.1371/journal.pone.0202303
  • Nguyen, N., Lee, L.M., Fashing, P.J., Nurmi, N.O., Stewart, K.M., Turner, T.J., Barry, T.S., Callingham, K.R., Goodale, C.B., Kellogg, B.S., Burke, R.J., Bechtold, E.K., Claase, M.J., Eriksen, G.A., Jones, S.C.Z., Kerby, J.T., Kraus, J.B., Miller, C.M., Trew, T.H., Zhao, Y., Beierschmitt, E.C., Ramsay, M.S., Reynolds, J.D., and Venkataraman, V.V. (2017). Comparative primate obstetrics: Observations of 15 diurnal births in wild gelada monkeys (Theropithecus gelada) and their implications for understanding human and nonhuman primate birth evolution. American Journal of Physical Anthropology 163: 14-29. (NPR)
  • Mekonnen, A., Fashing, P.J., Bekele, A., Hernandez-Aguilar, R.A., Rueness, E.K., Nguyen, N., and Stenseth, N.C. (2017). Impacts of habitat loss and fragmentation on the activity budget, ranging ecology and habitat use of Bale monkeys (Chlorocebus djamdjamensis) in the southern Ethiopian Highlands.  American Journal of Primatology DOI: 10.1002/ajp.22644.
  • Fashing, N.J., Ueckermann, E.A., Fashing, P.J., Nguyen, N., Back, A.M., and Allison, L.A. (2016). Bryobia abyssiniae (Prostigmata: Tetranychidae), a new species from the highlands of Ethiopia. International Journal of Acarology 42: 366-376.
  • Fashing, P.J. and Nguyen, N. (2016). Theropithecus gelada. In: N. Rowe (ed.). All the World’s Primates . East Hampton, NY: Pogonias Press, pp. 447-449.
  • Shapiro, A.E., Venkataraman, V.V., Nguyen, N., and Fashing, P.J. (2016). Dietary ecology of fossil Theropithecus: Inferences from dental microwear textures of extant geladas from ecologically diverse sites. Journal of Human Evolution 99: 1-9.
  • Nguyen, N., Fashing, P.J., Boyd, D.A., Barry, T.S., Burke, R.J., Goodale, C.B., Jones, S.C.Z., Kerby, J.T., Kellogg, B.S., Lee, L.M., Miller, C.M., Nurmi, N.O., Ramsay, M.S., Reynolds, J.D., Stewart, K.M., Turner, T.J., Venkataraman, V.V., Knauf, Y., Roos, C. and Knauf, S. (2015). Fitness impacts of tapeworm parasitism on wild gelada monkeys at Guassa, Ethiopia. American Journal of Primatology 77: 579-594.
  • Venkataraman, V.V., Kerby, J.T., Nguyen, N. Ashenafi, Z., and Fashing, P.J. (2015). Solitary Ethiopian wolves increase predation success on rodents when among grazing gelada monkey herds. Journal of Mammalogy 96: 129-137. (New Scientist)
  • Fashing, P.J., Nguyen, N., Venkataraman, V.V., and Kerby, J.T. (2014). Gelada feeding ecology in an intact ecosystem at Guassa, Ethiopia: Variability over time and implications for theropith and hominin dietary evolution. American Journal of Physical Anthropology 155(1): 1-16.
  • Venkataraman, V.V., Glowacka, H., Fritz, J., Clauss, M., Seyoum, C., Nguyen, N., and Fashing, P.J. (2014). Effects of dietary fracture toughness and dental wear on chewing efficiency in geladas (Theropithecus gelada). American Journal of Physical Anthropology 155(1): 17-32.
  • Nguyen, N. 2013. Primate behavioral endocrinology. In: Sterling, E.J., Bynum, N., and Blair M.E, editors.  Primate ecology and conservation: A handbook of techniques . Oxford, U.K.: Oxford University Press, pp. 224-237.
  • Fashing, P.J., Nguyen, N., Luteshi, P., Opondo, W., Cash, J.F., and Cords, M. 2012. Evaluating the suitability of planted forests for African forest monkeys: A case study from Kakamega Forest, Kenya. American Journal of Primatology 74: 77-90. (PDFPDF File )
  • Nguyen N., Gesquiere L., Alberts S.C., Altmann J. 2012. Sex differences in the mother-neonate relationship in wild baboons: social, experiential and hormonal correlates. Animal Behaviour 83:891-903. (PDFPDF File )
  • Fashing, P.J. and Nguyen, N. 2011. Behavior towards the dying, diseased, and disabled among animals and its relevance to paleopathology. International Journal of Paleopathology 1: 128-129. (PDFPDF File )
  • Fashing, P.J., Nguyen, N., Barry, T.S., Goodale, C.B., Burke, R.J., Jones, S.C.Z., Kerby, J.T., Lee, L.M., Nurmi, N.O., Venkataraman, V.V. (2011). Death among geladas (Theropithecus gelada): A broader perspective on mummified infants and primate thanatology. American Journal of Primatology 73: 405-409. (PDFPDF File ) (New ScientistOpens in new window ) (Wired MagazineOpens in new window )
  • Fashing, P.J., Nguyen, N., and Fashing, N.J. (2010). Behavior of geladas and other endemic wildlife during a desert locust outbreak at Guassa, Ethiopia: Ecological and conservation implications. Primates 51: 193-197. (PDFPDF File ) (CBC Quirks & QuarksOpens in new window ) (BBC Earth NewsOpens in new window )
  • Nguyen, N., Van Horn, R.C., Alberts S.C., Altmann J. (2009) “Friendships” between new mothers and adult males: adaptive benefits and determinants in wild baboons (Papio cynocephalus). Behavioral Ecology & Sociobiology. 63(9):1331-1344. (PDFPDF File ) (BBC Earth NewsOpens in new window )
  • Nguyen, N., Gesquiere, L.R, Wango, E.O., Alberts, S.C., Altmann, J. 2008. Late pregnancy glucocorticoid levels predict responsiveness in wild baboon mothers (Papio cynocephalusAnimal Behaviour 75:1747-1756. (PDFPDF File )
  • Fashing, P.J.; Mulindahabi, F.; Gakima, J.-B.; Masozera, M.; Mununura, I.; Plumptre, A.J.; Nguyen, N. 2007.  Activity and ranging patterns of Angolan colobus (Colobus angolensis ruwenzorii) in Nyungwe Forest, Rwanda: Possible costs of large group size. International Journal of Primatology 28: 529-550. (PDFPDF File )
  • Beehner, J. Nguyen, N., Alberts, S.C., Altmann, J. 2006. The endocrinology of pregnancy and fetal loss in wild baboons. Hormones and Behavior 49:688-699. (PDFPDF File )
  • Altmann, J.; Lynch, J.W.; Nguyen, N.; Alberts, S.C.; Gesquiere, L.R.  2004.  Life-history correlates of steroid concentrations in wild peripartum baboons. American Journal of Primatology 64: 95 – 106. (PDFPDF File )
  • Sterling, E.J.; Nguyen, N.; Fashing, PJ.  2000.  Spatial patterning in nocturnal prosimians: a review of methods and relevance to studies of sociality. American Journal of Primatology 51:3-19. (PDFPDF File )
  • Nguyen, N. 2000. A survey of Tonkin snub-nosed monkeys (Rhinopithecus avunculus) in northern Viet Nam. Folia Primatologica 71:157-160. (PDFPDF File )


Media Coverage of My Research

Welch, C. 2017. “Where the world's only grass-eating monkeys thrive.” National Geographic, April 2017, pages 72-95.

King, B.J. 2017. “A new view into the primate birthing process.” National Public Radio 2 February 2017. 

Holmes, B. 2015. “Monkeys’ cosy alliance with wolves looks like domestication.” New Scientist 5 June 2015. 

Platt, J.R. 2015. “Wolves and monkeys: unusual hunting buddies.” Scientific American 8 July 2015. 

Switek, B. 2011. “What death means to primates”. Wired 18 April 2011.Opens in new window

Marshall, M. 2010. “Bereaved animals grieve – if their lifestyle allows it”. New Scientist, issue 2791, December 2010.Opens in new window

Quirks & Quarks. 2010. “Monkeys munch on locust lunch”. Canadian Broadcasting Corporation science news radio program featured story and on-air interview with Dr. Peter J. Fashing. 22 May 2010.Opens in new window

Bourton, J. 2010. “Monkeys filmed feasting on locust swarm in Ethiopia”. BBC EARTH NEWSOpens in new window
30 April 2010.Opens in new window

Landis, B. Y. 2009. "Baboon moms pick up 'boys toys". Orange County Register 14 August 2009.

Matt, W. 2009. “Female baboons exploit chaperones”. BBC EARTH NEWS 16 July 2009.Opens in new window

PH.D. Thesis

Nguyen, N. 2006. Endocrine Correlates and Fitness Consequences of Variation in Mothering Behavior in Wild Baboons (Papio cynocephalus). Ph.D. in Ecology and Evolutionary Biology, Princeton University (PDFPDF File )


Division of Anthropology
California State University, Fullerton
800 N. State College Blvd.
Fullerton, CA 92834
Office: McCarthy Hall 059
Phone: (657) 278-7144

 Yellow baboons at water hole in Ambroseli, Kenya