Thor Hanson  Biologist & Author



Thor's research interests include birds, plants, primates, insects, endangered species, and the interface between human and natural systems. He has studied the effects of habitat fragmentation on rare plant communities, avian nest predation, and the reproductive ecology and genetic diversity of rainforest trees.

He is currently pursuing projects on Tufted Puffins, feathers, native bees, seeds, and an endangered butterfly, and is involved in an international effort to assess the ecological impacts of warfare.  His work on the occurrence of warfare in biodiversity hotspots was covered by news outlets around the world, including Reuters, Scientific American, The New York Times, and The Times of India.

Selected Publications:
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Hanson, T., and G. Wiles. in review. Washington State Status Report for the Tufted Puffin. Washington Department of Fish and Wildlife, Olympia, WA, 71 pp.

Hanson, T. in press.  The Unfeathered Bird (book review). Washington Birds 20.

Pfeifer, M., V. Lefabvre, L. Baeten, . . . T. Hanson, et al. in press. BIOFRAG - A new database for analysing biodiversity response to forest fragmentation. Ecology and Evolution.

Hanson, T., and G. Machlis. 2014. The broad view of warfare ecology: response to Marler. Environmental Conservation. 

Hanson, T. 2011. Macrolichens of the Pacific Northwest (book review). Western North American Naturalist 71: 570-571.

Hanson, T., 2011. War & biodiversity conservation:  the role of warfare ecology., in Machlis, G., Hanson, T., Spiric, Z., and J. McKendry., (eds). Warfare Ecology: Synthesis, Priorities, and Implications for Peace and Security. Springer, Dordrecht, Netherlands.

Machlis, G.E. and T. Hanson. 2009. Sobre la ecologia de los conflictos armados. Papeles 105: 11-23.

Hanson, T., Brooks, T.M., da Fonseca, G.A.B., Hoffman, M., Lamoreaux, J.F., Machlis, G., Mittermeier, C.G., Mittermeier, R.A., Pilgrim, J.D. 2009.  Warfare in biodiversity hotspots. Conservation Biology: 23: 578-587.

Donovan, S., Looney, C., Hanson, T., Sanchez-deLeon, Y., Wulfhorst, J. D., Eigenbrode, S., Jennings, M., Johnson-Maynard, J. and Bosque-Perez, N. 2009. Linking social and biophysical conservation perspectives in an endangered ecosystem: the Palouse as a model for bioregional planning. Ecology and Society: 14: 9. (URL:

Machlis, G., and T. Hanson. 2008. Warfare ecology. Bioscience 58: 729-736.

Hanson, T., Sanchez-deLeon, Y., Johnson-Maynard, J., and Brunsfeld, S. 2008.  The influence of soil and site characteristics on Palouse prairie plant communities. Western North American Naturalist 68: 231-240.

Hanson, T.R., Brunsfeld, S.J, Finegan, B. and L.P. Waits. 2008. Pollen dispersal and genetic structure of the tropical tree Dipteryx panamensis in a fragmented landscape. Molecular Ecology 17: 2060-2073.

Hanson, T. 2008. First observation of duetting in the Olive-backed Euphonia (Euphonia gouldi). Wilson Journal of Ornithology 120: 200-201.

Hanson, T.R., Brunsfeld, S.J, Finegan, B. and L.P. Waits. 2008. Characterization of microsatellite primers for the tetraploid tropical tree Dipteryx panamensis. Molecular Ecology Resources 8: 425-427.

Hanson, T. 2007. Consumption of Carapa guianensis bark by Cebus capucinus in La Reserva Biologica Indio-Maiz, Nicaragua. Neotropical Primates 14: 85-87.

Hanson, T., Brunsfeld, S., Finegan, B. and L. Waits. 2007. Conventional and genetic measures of seed dispersal for Dipteryx panamensis (Fabaceae) in continuous and fragmented Costa Rican rainforest. Journal of Tropical Ecology 23: 635-642.

Hanson, T., Newmark, W. and W. Stanley. 2007. Forest fragmentation and predation on artificial nests in the Usambara Mountains, Tanzania. African Journal of Ecology 45: 499-507. 

Hanson, T. 2006.  Effects of habitat fragmentation on the reproductive ecology and conservation genetics of the almendro (Dipteryx panamensis), a keystone rainforest tree.  Ph.D. Dissertation, University of Idaho, Moscow, Idaho.

Hanson, T., Brunsfeld, S., and B. Finegan. 2006. Variation in seedling density and seed predation indicators for the emergent tree Dipteryx panamensis in continuous and fragmented rainforest. Biotropica 38: 770-774.

Hanson, T.  2006.  To predate or depredate: what’s the word? Bulletin of the Ecological Society of America 87: 128-131.

Hanson, T. 2006. First observations of incubation behavior for the Stripe-breasted wren (Thryothorous thoracius). Ornitologia Neotropical 17: 453-456.

Hanson, T. 2000. Effects of Forest Disturbance and Fragmentation on Nest Predation in the Usambara Mountains, Tanzania. M.S. Thesis, University of Vermont, Burlington, Vermont.


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