Ernest H. Williams, Jr.

William R. Kenan Professor of Biology Emeritus

Contact Information




PhD, 1976, Princeton University

MA, 1970, Princeton University

BS, 1968, Trinity College (CT)

    (1970-73 USAF)


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

Courses I Have Taught

Bio 101

General Biology: Genetics and Evolution

Env St 150

Society and the Environment

The Nature Handbook For more information about my book on observing nature

Bio 237


Bio 441

Seminar in Evolutionary Biology

Env St 220

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

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

Bio 550-551

Biology Senior Thesis

Cemetery Demography For background information and data sets for the cemetery demography data-sharing project of the Ecological Society of America. From Jan 2011 (not being updated)

Monarch Butterfly Fund For an organization working to support the migration of monarch butterflies


career summary

** I have developed a new website for my nature photography. Please visit it at

After 41 years of college teaching, I am now officially retired. I will continue with research and writing projects. Some career highlights are these: Teaching - assigned 4760 final grades; taught Ecology 38 times, Introductory Biology 40 times, and Evolution 30 times (other courses, too). Scholarship - produced 4 books; published 64 articles (37 peer reviewed); gave 116 formal presentations. Service - chaired the Biology Dept 3 times, chaired the Environmental Studies Program (founding chair); chaired the college's Committee on Appointments, Committee on Academic Policy, and the Writing Advisory Committee. Held three endowed professorships.




PUBLICATIONS (ORCID number = 000-0002-9438-103X)


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)

Brower, L.P., E.H. Williams, et al. 2018. A long-term survey of spring monarch butterflies in north-central Florida. Journal of Natural History 52:2025-2046. Please email me for a copy.

Brower, L.P., E.H. Williams, P Jaramillo-Lopez, D.R. Kust, D.A. Slayback, & M.I. Ramirez. 2017. Butterfly mortality and salvage logging from the March 2016 storm in the Monarch Butterfly Biosphere Reserve in Mexico. American Entomologist 63(3):151-164. pdf

Zipf, L., E.H. Williams, R.B. Primack, & S. Stichter. 2017. Climate effects on late-season flight times of Massachusetts butterflies. International Journal of Biometeorology DOI 10.1007/s00484-017-1347-8. Email me for a copy or available at

Alcock, J., L.P. Brower, & E.H. Williams. 2016. Monarch butterflies use regenerating milkweeds for reproduction in mowed hayfields in northern Virginia. Journal of the Lepidopterists' Society 70:177-181. pdf

Pleasants, J.M., E.H. Williams, L.P. Brower, K.S. Oberhauser, & O.R. Taylor. 2016. Conclusion of no decline in summer monarch population not supported. Annals of the Entomological Society of America, on-line doi: 10.1093/aesa/sav115. pdf

Brower, L.P., D.A. Slayback, P. Jaramillo-Lopez, I. Ramirez, K.S. Oberhauser, E.H. Williams, & L.S. Fink. 2016. Illegal logging of ten hectares of forest in the Sierra Chincua monarch butterfly overwintering arera in Mexico. American Entomologist (summer, 2016):92-97. pdf

Williams, E.H., & L.P. Brower. 2016.A conservation concern: how many monarchs are there? News of the Lepidopterists' Society 58:90-93. pdf

Williams, E.H., & L.P. Brower. 2015. 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. ISBN 978-0-8014-5315-1. pdf

Fischer, S.J., E.H. Williams, L.P. Brower, & P.A. Palmiotto. 2015. Enhancing monarch butterfly reproduction by mowing fields of common milkweed. American Midland Naturalist 173(2):229-240. pdf

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 68:167-174. pdf.

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. Please email me for a copy.

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.
October, 2018