Center for Conservation Biology


2018 Science Advances, published Sept 19

Combating transnational organized crime by linking multiple large ivory seizures to the same dealer” Samuel K. Wasser, Amy Torkelson, Misa Winters, Yves Horeaux, Sean Tucker, Moses Y. Otiende, Frankie A.T. Sitam, John Buckleton and Bruce S. Weir

2018 Science Direct, published July 

Isolation of DNA from small amounts of elephant ivory: Sampling the cementum with total demineralization extraction”   M.Winters, A.Torkelson, R.Booth, C.Mailand, Y.Hoareau, S.Tucker, S.K.Wasser

2017 PLoS One, published June 29

Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca)   Samuel K. Wasser, Jessica I. Lundin, Katherine Ayres, Elizabeth Seely, Deborah Giles, Kenneth Balcomb, Jennifer Hempelmann, Kim Parsons, and Rebecca Booth

2016 Environmental Science and Technology

Modulation in Persistent Organic Pollutant Concentration and Profile by Prey Availability and Reproductive Status in Southern Resident Killer Whale Scat Samples” Jessica K Lundin, G Ylitalo, R Booth, B Anulacion, J Hempelmann, K Parsons, D Giles, E Seely, B Hanson, C Emmons, and S Wasser

2015 Science Express, published July 3rd

Genetic assignment of large ivory seizures of elephant ivory reveals Africa’s major poaching hotspots Samuel K Wasser, L Brown, C Mailand, S Mondo, W Clark, C Laurie, BS Weir

2015 Archives of Environmental Contamination and Toxicology, published 23 Aug

Persistent Organic Pollutant Determination in Killer Whale Scat Samples: Optimization of a Gas Chromatography/Mass Spectrometry Method and Application to Field Samples”  Jessica Lundin, R Dills, GM Ylitalo, M Bradley Hanson, CK Emmoms, G Schorr, J Ahmad, JA Hempelmann, KM Parsons, SK Wasser

2015 Environmental Pollution, 206  527e534

Polycyclic aromatic hydrocarbons in caribou, moose, and wolf scat samples from three areas of the Alberta oil sands”  Jessica Lundin, J Riffell, Samuel K Wasser

2012 PLoS ONE, 7(8): e42892

Using Detection Dogs to Conduct Simultaneous Surveys of Northern Spotted (Strix occidentalis caurina) and Barred Owls (Strix varia) Samuel K Wasser, Lisa S. Hayward, Jennifer Hartman, Rebecca K. Booth, Kristin Broms, Jodi Berg, Elizabeth Seely, Lyle Lewis, Heath Smith

2012 PLoS ONE, 7(6): e36842

Distinguishing the Impacts of Inadequate Prey and Vessel Traffic on an Endangered Killer Whale (Orcinus orca) Population Katherine L. Ayres, Rebecca K. Booth, Jennifer A. Hempelmann, Kari L. Koski, Candice K. Emmons, Robin W. Baird, Kelley Balcomb-Bartok, M. Bradley Hanson, Michael J. Ford, Samuel K. Wasser

2011 Proceedings of the Royal Society, Biological Sciences

Evidence that ship noise increases stress in right whales Rosalind M. Rolland, SE Parks, KE Hunt, M Castellote, PJ Corkeron, DP Nowacek, SK Wasser and SD Kraus

2011 Frontiers in Ecology and the Environment

The influences of wolf predation, habitat loss, and human activity on caribou and moose in the Alberta oil sands SK Wasser, JL Keim, ML Taper, SR Lele

2011 General and Comparative Endocrinology, 172: 382-391  

Glucocoticosteroid concentrations in feces and hair of captive caribou and reindeer following adrenocorticotropic hormone challenge NT Ashley, PS Barboza, BJ Macbeth, DM Janz, MRL Cattet, RK Booth, SK Wasser

2011 Ecosphere, 2(6): 1-20

Impacts of acute and long-term vehicle exposure on physiology and reproductive success of the northern spotted owl  LS Hayward, AE Bowles, JC Ha, SK Wasser

2011 PLoS One, 6(12): e28939

Resource Selection and Its Implications for Wide-Ranging Mammals of the Brazilian Cerrado C Vynne, J Keim, R Machado, J Marinho-Filho, L Silveira, M Groom, SK Wasser

2010 General and Comparative Endocrinology, 168(1): 1-7

Non-invasive measurement of thyroid hormone in feces of a diverse array of avian and mammalian species SK Wasser, JC Azkarate, RK Booth, L Hayward, K Hunt, K Ayers, C Vynne, K Gobush, D Canales-Espinosa, E Rodriguez-Luna

2010 General and Comparative Endocrinology, 169: 117-122

Eliminating the artificial effect of sample mass on avian fecal hormone metabolite concentration LS Hayward, RK Booth, SK Wasser

2010 Endangered Species Research, 11: 69-82

Species and stock identification of prey consumed by endangered southern resident killer whales in their summer range MB Hanson, RW Baird, JKB Ford, J Hempelmann-Halos, DM Van Doornik, JR Candy, CK Emmons, GS Schorr, B Gisborne, KL Ayers, SK Wasser, KC Balcomb, K Balcomb-Bartok, JG Sneva, MJ Ford

2010 Conservation Biology, 25(1): 154-162

Effectiveness of scat-detection dogs in determining species presence in a tropical savanna landscape C Vynne, JR Skalski, RB Machado, MJ Groom, ATA Jacomo, J Marinho-Filho, MB Ramos Neto, C Pomilla, L Silveira, H Smith, SK Wasser

2010 Science, 328: 1633-1635

Response — Consequences of Legal Ivory Trade SK Wasser, K Nowak, J Poole, J Hart, R Beyers, P Lee, K Lindsay, G Brown, P Granli, A Dobson

2010 Science, 327: 1331-1332

Elephants, Ivory, and Trade SK Wasser, J Poole, P Lee, K Lindsay, A Dobson, J Hart, I Douglas-Hamilton, G Wittemeyer, P Granli, B Morgan, J Gunn, S Alberts, R Beyers, P Chiyo, H Croze, R Estes, K Gobush, P Joram, A Kikoti, J Kingdon, L King, D Macdonald, C Moss, B Mutayoba, S Njumbi, P Omondi, K Nowak

2009 Scientific American, 68-76

The Ivory Trail SK Wasser, B Clark, C Laurie

2009 Journal of Zoo and Wildlife Medicine, 40(2): 382-384

First record of entodiniomorph ciliates in a carnivore, the maned wolf (Chrysocyon brachyurus) from Brazil” C Vynne and JM Kinsella

2009 Animal Behaviour, 78: 1079-1086

Behavioural correlates of low relatedness in African elephant core groups of a poached population KS Gobush and SK Wasser

2009 Journal of Wildlife Management, 73(7): 1233-1240

“Scent Matching Dogs Determine Number of Unique Individuals from Scat” SK Wasser, H Smith, L Madden, N Marks, C Vynne

2009 Molecular Ecology, 18: 722-734

“Genetic Relatedness and Disrupted Social Structure in a Poached Population of African Elephants” KS Gobush, B Kerr, SK Wasser

2009 Conservation Biology, 22: 1590-1599.

“Long-Term Impacts of Poaching on Relatedness, Stress Physiology, and Reproductive Output of Adult Female African Elephants” KS Gobush, BM Mutayoba, SK Wasser

2008 Natural History, pp.48-53

“Lucky dogs: Dogs sniff out scat from endangered animals, trumping more technical tracking methods” SK Wasser

2008 Conservation Biology, 22: 1065-1071

Combating the illegal trade in African elephant ivory with DNA forensics SK Wasser, WJ Clark, O Drori, ES Kisamo, C Mailand, B Mutayoba, M Stephens

2007 Nature Protocols, 2: 2228-2232

“Isolation of DNA from small amounts of elephant ivory”  C. Mailand, SK. Wasser

2007 Proceedings National Academy of Sciences, 104: 4228-4233

“Using DNA to track the origin of the largest ivory seizure since the 1989 trade ban” S Wasser,  C Mailand, R Booth, B Mutayoba, E Kisamo, B Clark, M Stevens

2006 Journal of Cetacean Research and Management, 8(2):121-125

“Faecal sampling using detection dogs to study reproduction and health in North Atlantic right whales (Eubalaena glacialis)” R Rolland, P Hamilton, S Kraus, B Davenport, R Gillett, S Wasser

2006 African Journal of Biotechnology, 5: 1588-1593

“The potential of mitochondrial DNA markers and polymerase chain-reaction fragment length polymorphism for domestic and wild species identification” A Malisa, P Gwakisa, S Balthazary,   S Wasser, B Mutayoba

2006 General and Comparative Endocrinology, 148: 260-272

Analysis of fecal glucocortocoids in the North Atlantic right whale (Eubalaena glacialis)          KE Hunt, RM Rolland, SD Kraus, SK Wasser

2005 African Journal of Biotechnology, 4: 1269-1274

Species and gender differentiation among domestic and wild animals using mitochondrial and sex-linked DNA markers  A Malisa, P Gwakisa, S Balthazary, S Wasser, B Mutayoba

2005 Zoo Biology, 24: 403-417

“Longitudinal monitoring of fecal testosterone in male Malayan sun bears (Ursus malaynus)”      H Hesterman, SK Wasser, JF Cockrem

2005 Annals of the New York Academy of Sciences, 1046: 109-137

“Noninvasive measures of reproductive function and disturbance in the barred owl, great horned owl, and northern spotted owl” SK Wasser, KE Hunt

2005 General and Comparative Endocrinology, 142: 308-317

“Assessing reproductive status of right whales (Eubalaena glacialis) using fecal hormone metabolites” RM Rolland, KE Hunt, SD Kraus, SK Wasser

2004 Proceedings National Academy of Sciences, 101: 14847-14852

“Assigning African elephant DNA to geographic region of origin. Applications to the ivory trade”  SK Wasser, A. Shedlock, K. Comstock, E. Ostrander, B. Mutayoba, M. Stephens.

2004 Behavioral Ecology and Sociobiology, 56: 328-337

“Infant handling and mortality in yellow baboons (Papio cynocephalus): evidence for female reproductive competition?”  S Kleindorfer, SK Wasser

2004 Behavioral Ecology and Sociobiology, 56: 338-345.

“Population trend alters the effects of maternal dominance rank on lifetime reproductive success in yellow baboons (Papio cynocephalus)” SK Wasser, GW Norton, S Kleindorfer, RJ Rhine

2004 Canadian Journal of Zoology, 82: 475-492

Scat detection dogs in wildlife research and management: Applications to grizzly and black bears in the Yellowhead Ecosystem, Alberta, Canada SK Wasser, B. Davenport, ER Ramage, KE Hunt, M Parker, C Clarke, G Stenhouse

2004 Physiological and Biochemical Zoology, (in press)

“Factors Associated With Fecal Glucocorticoids In Alaskan Brown Bears (Ursus arctos horribilis)” CG van der Ohe, SK Wasser, K. Hunt, C Servheen

2004 Physiology and Behavior, 80: 595-601

“Validation of a fecal glucocorticoid assay for Steller sea lions (Eumetopias jubatus)” KE Hunt,   A Trites, SK Wasser

2003 Physiological and Biochemical Zoology, 76: 918-928

“Effect of long-term preservation methods on fecal glucocorticoid concentrations of grizzly bear and African elephant” KE Hunt, SK Wasser

2003 General and Comparative Endocrinology, 134: 18-25

“Noninvasive reproductive steroid hormone estimates from fecal samples of captive female sea otters (Enhydra lutris)” S Larson, CJ Casson, SK Wasser

2003 Conservation Biology, 17: 1-4

“Amplifying nuclear and mitochondrial DNA from African Elephant Ivory: A tool for monitoring the ivory trade” KE Comstock, EA Ostrander, SK Wasser

2002 Molecular Ecology, 11:2489-2498

“Patterns of molecular genetic variation among African elephant populations” KE Comstock,      N Georgiadis, J Pecon-Slattery, AL Rocca, SJ O’Brien, SK Wasser

2002 Conservation Genetics, 3: 435-440

“An evaluation of long-term preservation methods for brown bear (Ursus arctos) faecal DNA samples” MA Murphy, LP Waits, KC Kendall, SK Wasser, JA Higbee, R Bogden

2002 Conservation Medicine: Ecological Health in Practice, pp 130-144

“Assessing stress and population genetics through non-invasive means”  Aguire, AA., RS Ostfeld, GM Taber, C House, MC Pearl (eds.) SK Wasser, KE Hunt, CM Clarke

2001 Wildlife Society Bulletin, 29: 899-907

“Fecal glucocorticoid assays and the physiological stress response in elk” JJ Millspaugh, RJ Woods, KE Hunt, KJ Raedeke, GC Brundige, BE Washburn, SK Wasser

2001 Reproductive Ecology and Human Evolution, pp. 137-158

“Reproductive filtering and the social environment” SK Wasser and N. Place

2001 Western Black Bear Workshop, 7: 24-29

“Technical considerations for hair genotyping methods in black bears” CM Clarke, DA Immell,   SK Wasser

2001 Ursus, 12: 237-240

“Fecal DNA methods for differentiating grizzly bears from black bears” CM Clarke, JA Fangman, SK Wasser

2001 Conservation Biology, 15: 1134-1142

“Non-invasive stress and reproductive measures of social and ecological pressures in free-ranging African elephants (Loxodonta africana)” CAH Foley, S Papageorge, SK Wasser

2000 General and Comparative Endocrinology, 120: 260-275

“A generalized fecal glucocorticoid assay for use in a diverse array of non-domestic mammalian and avian species” SK Wasser, KE Hunt, JL Brown, K Cooper, CM Crockett, U Bechert,            JJ Millspaugh, S Larson, SL Monfort

2000 Molecualr Ecology, 9: 993-1011

“Polymorphic microsatellite DNA loci identified in the African elephant (Loxodona africana)”     KE Comstock, SK Wasser, EA Ostrander

2000 American Journal of Primatology, 51: 229-241

“Lifetime reproductive success, longevity, and reproductive life history of yellow baboons (Papio cynocephalus) of Mikumi National Park, Tanzania”  RJ Rhine, G Norton, SK Wasser

1999 General and Comparative Endocrinology, 114: 269-278

“Serum prolactin concentrations in the captive female African elephant (Loxodonta africana): Potential effects of season and steroid hormone interactions” U.S. Bechert, L. Swanson,          SK Wasser, D.L. Hess, F. Strormshak

1999 American Journal of Obstetrics and Gynecology, 180: S272-274

“Stress and Reproductive Failure: An Evolutionary Approach with Applications to Premature Labor” SK Wasser

1998 Human Reproduction Update, 4: 430-438

“Ageing and Social Rank Effects on the Reproductive System of Free-Ranging Yellow Baboons (Papio cynocephalus) at Mikumi National Park, Tanzania”  S.K. Wasser, G.W. Norton, R.J. Rhine, S. Kleindorfer

1998 General and Comparative Endocrinology, 112: 96-107

“Longitudinal fecal steroid excretion in the maned wolves (Chrysocyon brachyurus)” A.L. Velloso, S.K. Wasser, S.L. Monfort, J.M. Dietz

1998 American Journal of Primatology, 44: 137-146

“Validity of an estimator of reproductive success” R.J. Rhine, G.W. Norton, D.M Hawkins, S.K. Wasser

1997 Zoo Biology, 6: 533-548

“Steroid metabolism and validation of noninvasive endocrine monitoring in the African wild dog (Lycaon pictus)” S.L. Monfort, S.K. Wasser, K.L. Mashburn, M. Burke, B.A. Brewer, S.R. Creel

1997 Zeitschrift fur Saugetierkunde, 62 Supplement 2: 27-31

“Faecal steroid analysis for monitoring ovarian and testicular function in diverse wild carnivore, primate and ungulate species” J.L. Brown, S.K. Wasser, D.E. Wildt, L.H. Graham, S.L. Monfort

1997 Molecular Ecology, 6: 1091-1097

“Techniques for application of fecal DNA studies of Ursids” S.K. Wasser, C.S. Houston, G.M. Koehler, G.G. Cadd, S.R. Fain

1997 Human Reproduction, 12: 1152-1155

“Utility of FSH, LH, estradiol and FSH:LH ratio in predicting reproductive age in normal women” Y.K. Kim, S.K. Wasser, V.Y. Fujimoto, N.A. Klein, D.E. Moore, M.R. Soules

1997 Conservation Biology, 11: 1019-1022

“Noninvasive physiological measures of disturbance in the Northern Spotted Owl” S.K. Wasser, K. Bevis, G. King, E. Hanson

1996 Endangered Species Update, 13: 57-60

“Safeguarding diversity: Challenges in developing a genome resource bank for California sea otters” J.A. Long, S.E. Larson and S.K. Wasser

1996 Proceedings of the 1st International Symposium on Physiologie and Ethology of Wild and Zoo Animal, Berlin, Germany, pp. 27-31

“Fecal steroid analysis for monitoring ovarian and testicular function in wild carnivore, primate and ungulate species” J.L. Brown, S.K. Wasser, D.E. Wildt. L.H. Graham, S.L. Monfort

1996 Biology of Reproduction, 55: 393-399

“Reproductive control in wild baboons measured by fecal steroids” S.K. Wasser

1996 General and Comparative Endocrinology, 102: 255-262

Excretory fate of estradiol and progesterone in the African elephant (Loxodonta africana) and patterns of fecal steroid concentrations throughout the estrous cycle S.K. Wasser,                    S. Papageorge, C. Foley, J.L. Brown

1995 Journal of Zoo and Wildlife Medicine, 26: 32-42

“In-vitro fertilization of Bornean orangutan (Pongo pygmaeus pygmaeus) gametes followed by embryo transfer into a surrogate hybrid orangutan (Pongo pygmaeus)” J.O. Joslin, W.D. Weissman, K. Johnson, M. Foster, S.K. Wasser and D. Collins

1995 Journal of Wildlife Management, 59: 889-894

“Using fecal steroids to evaluate reproductive function in female maned wolves” S.K. Wasser, A.D.L. Vellosa, M. Rodden

1995 Nature, 376: 219-220

“Costs of conception in baboons” S.K. Wasser

1995 American Journal of Primatology, 35: 15-30

“Environmental variation and developmental rate among free ranging yellow baboons (Papio cynocephalus)” L.M. Wasser and S.K. Wasser

1994 Biology of Reproduction, 51: 776-786

“Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured non-invasively in feces” J.L. Brown, S.K. Wasser, D.E. Wildt and L.H. Graham

1994 Journal of Reproduction and Fertility, 101: 213-220

“Excretion rates and metabolites of oestradiol and progesterone in baboon (Papio cynocephalus) faeces” S.K. Wasser, S.L. Monfort, J. Southers and D.E. Wildt

1994 Human Nature, 5: 293-206

“Psychosocial stress and infertility: Cause or effect?” S.K. Wasser

1993 Journal of Wildlife Management, 57: 400-407

“Monitoring reproduction in moose using urinary and fecal steroid metabolites” S.L. Monfort,  C.C. Schwartz and S.K. Wasser

1993 Biogeography and Ecology of the Forests of Eastern Africa, Cambridge, Cambridge University Press 1993

“The socioecology of interspecific associations among the forest monkeys of the Eastern Arc Mountains, Tanzania” J. Lovett and S.K. Wasser (Eds.)

“Introduction to the Biogeography and Ecology of the Forests of Eastern Africa” Lovett, J., and S.K. Wasser (Eds.)

1993 Behavior Ecology and Sociobiology, 32: 273-281

“Baboons adjust secondary sex ratio in response to predictors of sex-specific offspring survival” S.K. Wasser and G.W. Norton

1993 Journal of Reproduction and Fertility, 97: 569-574

“Effects of dietary fiber on faecal steroid measurements” S.K. Wasser, R. Thomas, P.P. Nair,     C. Guidry, J. Southers, J. Lucas, D.E. Wildt and S.L. Monfort

1993 Fertility and Sterility, 59: 685-689

“Psychosocial stress as a cause of infertility” S.K. Wasser, G. Sewall and M.R. Soules

1992 American Journal of Primatology, 27:261-274

“Secondary sex ratio and maternal dominance rank among wild yellow baboons (Papio cynocephalus) of Mikumi National Park, Tanzania” R.J. Rhine, G.W. Norton, J. Rogers and S.K. Wasser

1991 Journal of Reproduction and Fertility, 92: 415-423

“Rapid extraction of faecal steroids for measurement of reproductive cyclicity and early pregnancy in free-ranging yellow baboons” S.K. Wasser, S.L. Monfort, S.L. and D.E. Wildt

1990 Human Nature, 1: 3-25

“Infertility, abortion, and biotechnology: When its not nice to fool mother nature” S.K. Wasser

1988 Biology of Reproduction, 39: 862-872

“Excreted steroids in primate feces over the menstrual cycle and pregnancy” S.K. Wasser,         L. Risler, and R.A. Steiner

1988 American Journal of Primatology, 16(3): 199-212

“An eight year study of social and ecological correlates of mortality among immature baboons of Mikumi National Park, Tanzania” R.J. Rhine, S.K. Wasser, and G.W. Norton

1988 American Journal of Primatology, 16(2): 97-122

“Proximate and ultimate causation of reproductive suppression among female yellow baboons at Mikumi National Park, Tanzania” S.K. Wasser, and A.K. Starling

1987 American Journal of Primatology, 12: 91-100

“Measurement of excreted steroids in Macaca nemestrina” L. Risler, S.K. Wasser, G.P. Sackett

1987 Primate Conservation, 8: 167-168

“The value and problem of wildlife conservation in Tanzania” S.K. Wasser

1986 Ontogeny, Cognition, and Social Behaviour of Primates, Cambridge University Press, pp. 343-354

“Reproductive competition among female yellow baboons” J.G. Else and P.C. Lee (Eds.), S.K. Wasser, and A.K. Starling

1986 Primate Report, 14: 194-195

“Use of techniques to extract steroid hormones from primate feces” S.K. Wasser, L. Risler,    L.M. Wasser

1986 Journal of Psychosomatic Obstetrics and Gynecology, 5: 153-175

“Reproductive failure among women: Pathology or adaptation?” S.K. Wasser, and D.Y. Isenberg

1986 Animal Behaviour, 34: 623-624

“Review of Infanticide: Comparative and Evolutionary Perspectives”  G. Hausfater and S.B. Hrdy (Eds.), Aldine , NY (1984). S.K. Wasser. 1986

1985  Primate Conservation, 6: 34

“Current conservation status of the Mwanihana Rain Forest, Uzungwa Mountains, Sanje, Tanzania” S.K. Wasser

1984 Animal Behaviour, 32(4): 953

“Review of Harems and Other Horrors. By A.I. Dagg, Otter Press, Montreal (1983)” S.K. Wasser

1983 The Quarterly Review of Biology, 58(4): 513-538

Reproductive suppression among female mammals: implications for biomedicine and sexual selection theory S.K. Wasser, and Barash, D.P.

1983 Social Behavior of Female Vertebrates, NY, Academic Press.  

“The establishment and maintenance of sex biases” S.K. Wasser, and M.L. Waterhouse

1983 Social Behavior of Female Vertebrates, New York , Academic Press

“Reproductive competition and cooperation among female yellow baboons” S.K. Wasser (Ed.)

1982 Human Ecology, 13: 281-2

“Review of Beyond Sociobiology. By: J.D. Baldwin and J.O. Baldwin, New York, Elsevier (1981)” S.K. Wasser

1982 American Naturalist, 117: 911-920

“Reciprocity and the trade-off between associate quality and relatedness” S.K. Wasser

1981 Ethology and Sociobiology, 2: 91-93.

“The “selfish” allomother” S.K. Wasser, and D.P. Barash

1978 Carnivore, 1(3): 27-40

“Structure and function of play in the tiger” S.K. Wasser