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Professor Samuel Wasser

Professor Samuel Wasser

Academic Visitor

Room 3.07, David Attenborough Building


Visiting professor on sabbatical from the University of Washington, where I am a Professor in the Department of Biology, Director of the Center for Conservation Biology and hold the endowed chair in Conservation Biology. 

Research Interests

Monitoring human impacts on wildlife communities over large spatial scales. My lab pioneered highly accessible noninvasive tools to measure DNA, hormones and toxins in feces, often located by detection dogs with very low collection bias. This allows us to assess human impacts on population abundance, resource selection, physiological stress and community level interactions across a wide variety of vertebrates. Examples of my most recent work include: examining how prey abundance, ecotourism and toxins impacts health and reproductive success of fish eating killer whales; impacts of wolf recovery on medium to large carnivores and their prey in high human use landscapes; and use of DNA forensics to examine illegal trade in elephant ivory and pangolins. 

Key Publications

Wasser, S.K. 1982.  Reciprocity and the trade-off between associate quality and relatedness.  American Naturalist  117: 911-920.

Wasser, S.K. (Ed.). 1983. Social Behavior of Female Vertebrates, New York, Academic Press.

Wasser, S.K., and D.P. Barash. 1983. Reproductive suppression among female mammals:  Implications for biomedicine and sexual selection theory. Quarterly  Review of Biology 56: 513-538.

Wasser, S.K. 1990. Infertility, abortion, and biotechnology: When its not nice to fool mother nature.  Human Nature  1: 3-25.

Wasser, S.K., R. Thomas, P.P. Nair, C. Guidry, J. Southers, J. Lucas, D.E. Wildt and S.L. Monfort. 1993. Effects of dietary fiber on faecal steroid measurements.  Journal of Reproduction and Fertility 97: 569-574.

Wasser, S.K. and G.W. Norton. 1993. Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival.  Behavior Ecology and Sociobiology 32: 273-281.

Lovett, J. and S.K. Wasser (Eds.).  1993.  Biogeography and Ecology of the Forests of Eastern Africa.  Cambridge, Cambridge University Press.

Wasser, S.K. 1996.  Reproductive control in wild baboons measured by fecal steroids.  Biology of Reproduction 55: 393-399.

Wasser, S.K., K. Bevis, G. King, E. Hanson. 1997. Noninvasive physiological measures of disturbance in the Northern Spotted Owl.  Conservation Biology 11: 1019-1022.

Wasser, SK, KE Hunt, JL Brown, K Cooper, CM Crockett, U Bechert, JJ Millspaugh, S Larson, SL Monfort.  2000.  A generalized fecal glucocorticoid assay for use in a diverse array of non-domestic mammalian and avian species.  General and Comparative Endocrinology 120: 260-275.

Foley, CAH, S Papageorge, SK Wasser. 2001.  Non-invasive stress and reproductive measures of social and ecological pressures in free-ranging African elephants (Loxodonta africana).  Conservation Biology 15: 1134-1142.

Wasser, SK and N. Place.  2001.  Reproductive filtering and the social environment.  In:  Ellison, P. (ed.) Reproductive Ecology and Human Evolution, Aldine  DE Gruyter, Hawthorne, NY, pp. 137-158.

Comstock, KE, N Georgiadis, J Pecon-Slattery, AL Rocca, SJ O’Brien, SK Wasser.  2002.  Patterns of molecular genetic variation among African elephant populations.  Molecular Ecology  11:2489-2498.

Wasser, SK, B. Davenport, ER Ramage, KE Hunt, M Parker, C Clarke, G Stenhouse.  2004.  Scat detection dogs in wildlife research and management:  Applications to grizzly and black bears in the Yellowhead Ecosystem, Alberta, Canada.  Canadian Journal of Zoology 82: 475-492.

Wasser, SK,  GW Norton, S Kleindorfer, RJ Rhine.  2004.  Population trend alters the effects of maternal dominance rank on lifetime reproductive success in yellow baboons (Papio cynocephalus).  Behavioral Ecology and Sociobiology 56: 338-345.

Wasser SK,  A. Shedlock, K. Comstock, E. Ostrander, B. Mutayoba, M. Stephens.  (2004).  Assigning African elephant DNA to geographic region of origin.  Applications to the ivory trade.  Proceedings National Academy of Sciences 101: 14847-1485.

Wasser, SK, C Mailand, R. Booth, B Mutayoba,  ES Kisamo, B Clark, M Stephens. 2007. Using DNA to track the origin of the largest ivory seizure since the 1989 trade ban.  Proceedings of the National Academy of Sciences 104(10): 4228-4236.

Mailand, C., SK. Wasser. 2007.  Isolation of DNA from small amounts of elephant ivory.  Nature Protocols 2: 2228-2232.

Wasser, SK, WJ Clark, O Drori, ES Kisamo, C Mailand, B Mutayoba, M Stephens.  2008.  Combating the illegal trade in African elephant ivory with DNA forensics.  Conservation Biology 22: 1065-1071.

Gobush, KS, BM Mutayoba, SK Wasser.  2008. Long-term impacts of poaching on relatedness, stress physiology, and reproductive output of adult female African elephants.  Conservation Biology 22: 1590-1599.

Gobush, KS, B Kerr, SK Wasser. 2009. Genetic relatedness and disrupted social structure in a poached population of African elephants.  Molecular Ecology 18: 722–734.

Gobush, KS and SK Wasser. 2009. Behavioural correlates of low relatedness in African elephant core groups of a poached population.  Animal Behaviour 78: 1079-1086.

Wasser, SK, B Clark, C Laurie.  2009. The Ivory Trail.  Scientific American July, 2009.

Wasser, SK et al. 2010.  Elephants, ivory and trade.  Science 327: 1331-1332.

Wasser, SK, J Cristòbal-Azkarate, RK Booth, L Hayward, K Hunt, K Ayres, C Vynne, K Gobush, D Canales-Espinosa, E. Rodríguez-Luna. 2010. Non-invasive measurement of thyroid hormone in feces of a diverse array of avian and mammalian species. General and Comparative Endocrinology 168: 1-7. Doi: 10.1016/j.ygcen.2010.04.004

Wasser, SK et al. 2010. Consequences of legal ivory trade. Science 328: 1633-1635.

Hayward, LS, AE Bowles, JC Ha, SK Wasser. 2011.  Impacts of acute and long-term vehicle exposure on physiology and reproductive success of northern spotted owls. Ecosphere 26: Article 65.

Wasser, SK, JL Keim, ML Taper, SR Lele. 2011. The influences of wolf predation, habitat loss and human activity on caribou and moose in the Alberta oil sands. Frontiers in Ecology and the Environment 9: 546-551.

Vynne, C., JL Keim, RB Macahado, J Marinho-Filho, L Silvera, MJ Groom, SK Wasser. 2011.  Resource selection and its implications for wide-ranging mammals of the Brazilian Cerrado. PloS ONE 6(12): e28939.

Rolland, RM, SE Parks, KE Hunt, M Castellote, PJ Corkeron, DP Nowacek, SK Wasser and SD Kraus. 2012. Evidence that ship noise increases stress in right whales. Proceedings of the Royal Society B, Biological Sciences 279: 2363-2368.

Ayres KL RK Booth, JA Hempelmann, KL Koski, CK Emmons, RW Baird, K Balcomb-Bartok, MB Hanson, MJ Ford, SK Wasser. 2012. Distinguishing the impacts of inadequate prey and vessel traffic on an endangered killer whale (Orcinus orca) population. PLoS One 7(6): e36842.

Wasser SK, LS Hayward, J Hartman, RK Booth, K Broms, J Berg, E Seely, L Lewis, H Smith. 2012. Using detection dogs to conduct simultaneous surveys of northern spotted (Strix occidentalis caurina) and barred owls (Strix varia). PLoS One 7(8): e42892.

Stetz J, K Hunt, KC Kendall, SK Wasser. 2013. Effects of exposure, diet, and thermoregulation on fecal glucocorticoid measures in wild bears. PLoS One 8(2): e55967.

Epps CW, SK Wasser, JL Keim, BK Mutayoba, JS Brashares. 2013. Quantifying past and present connectivity illuminates a rapidly changing landscape for the African elephant. Molecular Ecology 22: 1574-1588.

Vynne C, RK Booth, SK Wasser 2014. Physiological implications of landscape use by free-ranging maned wolves (Chrysocyon brachyurus) in Brazil. Journal of Mammology 95(4): in press.

Wasser SK, L Brown, C Mailand, S Mondol, W Clark, C Laurie, BS Weir. 2015. Genetic assignment of large seizures of elephant ivory reveals Africa’s major poaching hotspots. Science 349: 84-87.

Lundin JI, JA Riffell, SK Wasser. 2015. Polycyclic aromatic hydrocarbons in caribou, moose, and wolf scat samples from three areas of the Alberta oil sands. Environmental Pollution 206: 527-534.

Lundin JI, RL Dills, GM Ylitalo, MB Hanson, CK Emmons, GS Schorr, JA Hempelmann, KM Parsons, SK Wasser. 2015. Persistent organic pollutant determination in killer whale scat samples: Optimization of a gas chromatography/mass spectrometry method and application to field samples. Arch Environ Contam Toxicol DOI 10.1007/s00244-015-0218-8.

Mondol S, I Moltke, J Hart, M Keigwin, L Brown, M Stephens, SK Wasser. 2015. New evidence for hybrid zones of forest and savanna elephants in Central and West Africa.  Molecular Ecology 24: 6134-6147.

Lundin JI, GM Ylitalo, RK Booth, B Anulacion, JA Hempelmann, KM Parsons, DA Giles, EA Seely, MB Hanson, CK Emmons, SK Wasser. 2016. Modulation in persistent organic pollutant concentration and profile by prey availability and reproductive status in southern resident killer whale scat samples. Environ. Sci Technol DOI: 10.1021/acs.est.6b00825

Cerling, TE, JE Barnette, LA Chesson, I Douglas-Hamilton, KS Gobush, KT Uno, SK Wasser, X Xu. 2016. Radiocarbon dating of seized ivory confirms rapid decline in African elephant populations and provides insight into illegal trade. Proceedings National Academy of Sciences, in press.

Wasser, SK, JL Lundin, K Ayres, E Seely, D Giles, K Balcomb, J Hempelmann, K Parsons, R Booth. Population growth is limited by nutritional impacts on pregnancy success in endangered southern resident killer whales (Orcinus orca). PLOS One 12(6): e0179824.