Ernest H. Williams, Jr.

William R. Kenan Professor of Biology

Hamilton College Contacts


2037 Science Center


PhD, 1976, Princeton University

MA, 1970, Princeton University

BS, 1968, Trinity College (CT)

    (1970-73 USAF)


the population biology, chemical ecology, and conservation of butterflies, esp. the monarch Danaus plexippus, the checkerspot Euphydryas gillettii, and the frosted elfin Callophrys irus

Courses Taught

Bio 101 (fall, team-taught)

General Biology: Genetics and Evolution

Env St 150 (occasionally)

Society and the Environment

The Nature Handbook For more information about my recent book

Bio 237 (fall, team-taught)


Bio 441 (spring)

Seminar in Evolutionary Biology

Env St 220 (occasionally)

Forever Wild: The Cultural and Natural Histories of the Adirondack Park

Link to the annual trips of the Ecology class to Whiteface Mtn

Bio 550-551 (fall and spring)

Biology Senior Thesis

Utica Marsh For information about the Utica Marsh and the Utica Marsh Council

Cemetery Demography For background information and data sets for the cemetery demography data-sharing project of the Ecological Society of America. Newly updated Jan 2011.

Faculty affiliate to the men's cross-country and indoor and outdoor track teams


running, biotrivia, Wyoming, family






Williams, E.H., Jr. (ed.) 2012. Pathways to Excellence in Teaching. Couper Press, Clinton. NY. 81 pp. (softcover) ISBN 978-1-937370-06-0

Williams, E.H., Jr. 2005. The Nature Handbook: A Guide to Observing the Great Outdoors. Oxford Univ. Press, NY. 263 pp. (softcover) ISBN 0-19-517194-2

Stokes, D., L. Stokes, & E. Williams. 1991. Stokes Butterfly Book. Little, Brown & Co., Boston. 96 pp. ISBN 0-316-81780-5

Williams, E.H. (ed.). 1990. A Marsh for All Seasons: Information and Teacher's Guide for Utica Marsh. Utica Marsh Council, Utica, NY

Selected Articles and Chapters (click on pdf to download a copy)

Williams, E.H., S.B. Stichter, C. Hitchcock, C.A. Polgar, & R.B. Primack. 2014. Phenological advancement of Lycaenid butterflies in Massachusetts. Journal of the Lepidopterists' Society, in press.

Williams, E.H., & L.P. Brower. 2014. Microclimatic protection of overwintering monarch butterflies provided by Mexico's high elevation Oyamel fir forests: a review. Chap. 9 In: K. Oberhauser,S. Altizer, & K. Nail, eds., Monarchs in a Changing World: Biology and Conservation of an Iconic Insect, Cornell Univ. Press, Ithaca, NY. in press.

Polgar, C.A., R.B. Primack, E.H. Williams, S. Stichter, & C. Hitchcock. 2013. Climate effects on the flight period of Lycaenid butterflies in Massachusetts. Biological Conservation 160:25-31. pdf

Williams, E.H. 2012. Population loss and gain in the rare butterfly Euphydryas gillettii (Nymphalidae). Journal of the Lepidopterists' Society 66:147-155. pdf

Williams, E.H. 2012. Epilogue: what students tell us. pp. 77-81 in E.H. Williams (ed.), Pathways to Excellence in Teaching, Couper Press, Clinton, NY. pdf

Van Hook, T., E.H. Williams, L.P. Brower, S. Borkin, & J. Hein. 2012. A standardized protocol for ruler-based measurement of wing length in monarch butterflies, Danaus plexippus L. (Nymphalidae, Danainae). Tropical Lepidoptera Research 22(1):42-52. pdf

Brower, L.P., O.R. Taylor, & E.H. Williams. 2012. Response to Davis: choosing relevant evidence to assess monarch population trends. Insect Conservation and Diversity 5:327-329. (published on-line October, 2011; doi: 10.1111/j.1752-4598.2011.00176.x). pdf [The definitive version is available at]

Williams, E.H. 2012. Long term effects of climate on two pond predators. American Midland Naturalist 167:336-343. pdf

Brower, L.P., O.R. Taylor, E.H. Williams, D.A. Slayback, R.R. Zubieta, & M.I. Ramirez. 2012. Decline of monarch butterflies overwintering in Mexico: Is the migratory phenomenon at risk? Insect Conservation and Diversity 5(2):95-100. (published on-line March, 2011; doi: 10.1111/j.1752-4598.2011.00142.x). pdf [The definitive version is available at]

Brower, L.P., E.H. Williams, L.S. Fink, D.A. Slayback, M.I. Ramirez, M.I. Limon Garcia, R.R. Zubieta, S.B. Weiss, W.H. Calvert, & W. Zuchowski. 2011. Overwintering clusters of the monarch butterfly coincide with the least hazardous vertical temperatures in the oyamel forest. Journal of the Lepidopterists' Society 65(1):27-46. pdf

Williams, E.H., P.D. Reynolds, & O. Oerlemans. 2010. Interdisciplinary teaching about the Adirondacks. In: P. Cenkl (ed.), Nature and Culture in the Northern Forest, Univ. Iowa Press. pdf

Brower, L.P., E.H. Williams, D.A. Slayback, L.S. Fink, M.I. Ramirez, R.R. Zubieta, M.I. Limon Garcia, P. Gier, J.A. Lear, & T. van Hook. 2009. Oyamel fir forest trunks provide thermal advantages for overwintering monarch butterflies in Mexico. Insect Conservation and Diversity 2:163-175. pdf

Pfitsch, W.A., & E.H. Williams. 2009. Habitat restoration for lupine and specialist butterflies. Restoration Ecology 17(2):226-233. pdf

Brower, L.P., E.H. Williams, L.S. Fink, R.R. Zubieta Hernandez, & M.I. Ramirez. 2008. Monarch butterfly clusters provide microclimatic advantages during the overwintering season in Mexico. Journal of the Lepidopterists' Society 62:177-188. pdf

Boggs, C.L., C.E. Holdren, I.G. Kulahci, T.C. Bonebrake, B.D. Inouye, J.P. Fay, A. MacMillan, E.H. Williams, & P.R. Ehrlich. 2006. Delayed population explosion of an introduced butterfly. Journal of Animal Ecology 75:466-475. pdf

Kocher, S.D., & E.H. Williams. 2000. The diversity and abundance of North American butterflies vary with habitat disturbance and geography. Journal of Biogeography 27(4):785-794. pdf

Brooks, J.S., E.H. Williams, & P. Feeny. 1996. Quantification of contact oviposition stimulants for Black Swallowtail butterfly, Papilio polyxenes, on the leaf surfaces of wild carrot, Daucus carota. Journal of Chemical Ecology 22(12):2341-2357. pdf

Williams, E.H. 1995. Fire-burned habitat and reintroductions of the butterfly Euphydryas gillettii (Nymphalidae). Journal of the Lepidopterists' Society 49:183-191. pdf

Bowers, M.D., & E.H. Williams. 1995. Variable chemical defence in the checkerspot butterfly Euphydryas gillettii (Lepid.: Nymphalidae). Ecological Entomology 20:208-212.


Selected Non-technical Publications

Williams, E.H. 2012. Microclimates and the survival of overwintering monarchs. American Butterflies 20(2):8-13. pdf

Williams, E.H. 2009. Lifestyles of the scaled and beautiful: Pearl and Northern Crescents. American Butterflies 17(2):4-13. pdf

Williams, E.H. 2006. Baltimore Checkerspots: Butterflies of privilege. American Butterflies 14(2):4-13. pdf

Williams, E.H. 2002. Harris' Checkerspot: A very particular butterfly. American Butterflies 10(2):18-25. pdf

Willaims, E.H. 2001. Gillett's Checkerspot: Life in a mountain meadow. American Butterflies 9(2):6-13 pdf

modified by
Ernest H. Williams, Jr.
February 27, 2014