Postal Address:

Robert Colwell
University of Connecticut
75 N. Eagleville Road, Unit 3043
Storrs, CT 06269-3043, U.S.A.

Research

Biogeography theory and models. Biodiversity inventory, biodiversity informatics, and biodiversity statistics. Species interactions and coevolution, especially between plants and animals (arthropods, hummingbirds). Evolution in structured populations. Biology and public policy.

Click here to download a recent CV.

Software Tools & Documentation

Colwell, R. K. 2011. Biota 2: The biodiversity database manager. Software and 880 p. Manual. As of September 15, 2011, Biota is open-source software, distributed under a BSD-3 Open Source License. You may now freely download, use, and distribute fully-enabled copies of the standalone desktop versions of Biota 2.04 (BiotaAppWin and BiotaAppMac) at zero cost. More than 1000 users in 40 countries and 48 U.S. states.

Colwell, R. K. 2011. EstimateS, Version 8.2: Statistical Estimation of Species Richness and Shared Species from Samples (Software and User's Guide). Freeware for Windows and Mac OS. (EstimateS has been downloaded more than 40,000 times by users in more than 100 countries. It has been cited in more than 3500 publications.)

Colwell, R. K. 2011. RangeModel, Version 5: a Monte Carlo simulation tool for assessing geometric constraints on species richness. (Simulation and analysis software.) Freeware for Windows and Mac OS.

Recent and Selected Publications

Reverse chronological order, alphabetical by author within years.

Click here to go to Colwell's GoogleScholar Profile.

Click here to download a recent CV with a complete list of publications.

References marked "Download pdf" are available here for downloading for one-time personal use, in compliance with copyright law. When asked for Name and Password, enter guest for Name and ref for Password.

Colwell, R. K., R. R. Dunn, and N. C. Harris. In press. Coextinction and persistence of dependent species in a changing world. Annual Review of Ecology, Evolution and Systematics 43.

Eren, M. I., A. Chao, W. H. Hwang, and R. K. Colwell. In press. Estimating the richness of a population when the maximum number of classes is fixed: a nonparametric solution to an archaeological problem. PLoS One.

Levin, S., R. K. Colwell, G. Daily, S. Diaz, P. Kareiva, D. Karl, G. M. Mace, C. Perrings, D. Tilman, and M. G. Turner, editors. In press. Encyclopedia of biodiversity. Academic Press, NY.

Colwell, R. K., A. Chao, N. J. Gotelli, S.-Y. Lin, C. X. Mao, R. L. Chazdon, and J. T. Longino. 2012. Models and estimators linking individual-based and sample-based rarefaction, extrapolation, and comparison of assemblages. Journal of Plant Ecology 5:3-21. Online open, click here. Download pdf.

Gotelli, N. J., A. Chao, R. K. Colwell, W. H. Hwang, and G. R. Graves. 2012. Specimen-based modeling, stopping rules, and the extinction of the Ivory-billed Woodpecker Conservation Biology 26:47-56. Download pdf.

Colwell, R. K. 2011. Biogeographical gradient theory. Pages 309-330 in S. M. Scheiner and M. R. Willig, editors. The theory of ecology. University of Chicago Press, Chicago.

Chazdon, R. L., A. Chao, R. K. Colwell, S.-Y. Lin, N. Norden, S. G. Letcher, D. B. Clark, B. Finegan, and J. P. Arroyo. 2011. A novel statistical method for classifying habitat generalists and specialists. Ecology 92:1332–1343. Download pdf.

Gotelli, N. J. and R. K. Colwell. 2011. Estimating species richness. Pages 39-54 in A. E. Magurran and B. J. McGill, editors. Frontiers in measuring biodiversity. Oxford University Press, New York. Download pdf.

Longino, J. T. and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3):art29, doi:10.1890/ES10-00200.1. Online open, click here. Download pdf.

McCain, C. and R. K. Colwell. 2011. Assessing the threat to montane biodiversity from discordant shifts in temperature and precipitation in a changing climate. Ecology Letters 14:1236-1245. Download pdf.

Rahbek, C. and R. K. Colwell. 2011. News and Views: Species loss revisited. Nature 473:288-289. Download pdf.

Colwell, R. K. and T. F. Rangel. 2010. A stochastic, evolutionary model for range shifts and richness on tropical elevational gradients under Quaternary glacial cycles. Philosophical Transactions of the Royal Society B 365: 3695–3707. Download pdf.

Chao, A., R. K. Colwell, C.-W. Lin, and N. Gotelli. 2009. Sufficient sampling for asymptotic minimum species richness estimators. Ecology 90:1125-1133. Download pdf.

Colwell, R. K., N. J. Gotelli, C. Rahbek, G. L. Entsminger, C. Farrell, and G. R. Graves. 2009. Peaks, plateaus, canyons, and craters:   The complex geometry of simple mid-domain effect models. Evolutionary Ecology Research 11:355-370. Download pdf.

Colwell, R. K. and T. F. Rangel. 2009. Hutchinson's duality: the once and future niche. PNAS (Early Edition), cgi doi 10.1073 pnas.0901650106. Download pdf.

Dunn, R. R., N. C. Harris, R. K. Colwell, L. P. Koh, and N. S. Sodhi. 2009. The sixth mass coextinction: are most endangered species parasites and mutualists? Proceedings of the Royal Society B: Biological Sciences 276:3037-3045. Download pdf.

Gotelli, N., M. J. Anderson, H. T. Arita, A. Chao, R. K. Colwell, S. R. Connolly, D. J. Currie, R. R. Dunn, G. R. Graves, J. L. Green, J. A. Grytnes, Y.-H. Jiang, W. Jetz, S. K. Lyons, C. M. McCain, A. E. Magurran, C. Rahbek, T. F. L. V. B. Rangel, J. Soberon, C. O. Webb, and M. R. Willig. 2009. Patterns and causes of species richness: a general simulation model for macroecology. Ecology Letters 12:873-886. Download pdf.

Kumar, A., J. T. Longino, R. K. Colwell, and S. O'Donnell. 2009. Elevational patterns of diversity and abundance of eusocial paper wasps (Vespidae) in Costa Rica. Biotropica 41:338-346.

Carranza, A., R. K. Colwell, and T. F. L. V. B. Rangel. 2008. Distribution of megabenthic gastropods along environmental gradients: the mid-domain effect and beyond. Marine Ecology Progress Series 367:193-202.

Colwell, R. K. 2008. RangeModel: Tools for exploring and assessing geometric constraints on species richness (the mid-domain effect) along transects. Ecography 31:4-7. Download pdf.

Colwell, R. K., G. Brehm, C. Cardelús, A. C. Gilman, and J. T. Longino. 2008. Global warming, elevational range shifts, and lowland biotic attrition in the wet tropics. Science 322:258-261. Download pdf.

Sodhi, N. S., L. P. Koh, K. S.-H. Peh, H. T. W. Tan, R. L. Chazdon, R. T. Corlett, T. Lee, M., R. K. Colwell, B. W. Brook, C. H. Sekercioglu, and C. J. A. Bradshaw. 2008. Correlates of extinction proneness in tropical angiosperms. Diversity and Distributions 14:1-10. Download pdf.

Brehm, G., R. K. Colwell, and J. Kluge. 2007. The role of environment and mid-domain effect on moth species richness along a tropical elevational gradient. Global Ecology & Biogeography 16:205-219. Download pdf.

Horner-Devine, M. C., J. M. Silver, L. M. A, B. J. M. Bohannan, R. K. Colwell, J. A. Fuhrman, J. L. Green, C. R. Kuske, J. B. H. Martiny, L. Øvreås, A.-L. Reysenbach, and G. Muyzer. 2007. A comparison of taxon co-occurrence patterns for macro- and microorganisms. Ecology 88: 1345-1353.

Lees, D. C., and R. K. Colwell. 2007. A strong Madagascan rainforest MDE and no equatorward increase in species richness: Re-analysis of "The missing Madagascan mid-domain effect," by Kerr J.T., Perring M. & Currie D.J (Ecology Letters 9:149-159, 2006). Ecology Letters 10:E4-E8. Download pdf.

Rahbek, C., N. Gotelli, R. K. Colwell, G. L. Entsminger, T. F. L. V. B. Rangel, and G. R. Graves. 2007. Predicting continental-scale patterns of bird species richness with spatially explicit models. Proceedings of the Royal Society of London Series B 274:165-174 . Download pdf or read online.

Rangel, T. F. L. V. B., J. A. F. Diniz-Filho, and R. K. Colwell. 2007. Species richness and evolutionary niche dynamics: a spatial pattern-oriented simulation experiment. American Naturalist. 274: 165-174. Download pdf.

Cardelús, C., R. K. Colwell, and J. E. Watkins, Jr. 2006. Vascular epiphyte distribution patterns: explaining the mid-elevation richness peak. J. Ecology 94: 144-156. Download pdf.

Chao, A., R. L. Chazdon, R. K. Colwell, and T.-J. Shen. 2006. Abundance-based similarity indices and their estimation when there are unseen species in samples. Biometrics 62:361-371. Download pdf.

Dunn, R. R., R. K. Colwell, and C. Nilsson. 2006. The river domain: why are there more species halfway up the river? Ecography 29:251-259. Download pdf.

Watkins, J. E., Jr., C. Cardelús, R. C. Moran, and R. K. Colwell. 2006. Diversity and distribution of ferns along an elevational gradient in Costa Rica. American Journal of Botany 93:73-83. Download pdf.

Colwell, R. K., C. Rahbek, and N. Gotelli. 2005. The mid-domain effect: there's a baby in the bathwater. American Naturalist 166:E149–E154. Download pdf or read online.

Bunker, D. E., F. DeClerck, J. C. Bradford, R. K. Colwell, I. Perfecto, O. L. Phillips, M. Sankaran, and S. Naeem. 2005 (20 October). Species loss and aboveground carbon storage in a tropical forest. Science (Express Reports) 10.1126/science.1117682:1-5. Download pdf.

Chao, A., R. L. Chazdon, R. K. Colwell, and T.-J. Shen. 2005. A new statistical approach for assessing compositional similarity based on incidence and abundance data. Ecology Letters 8:148-159. Download pdf.

Mao, C. X., and R. K. Colwell. 2005. Estimation of species richness: mixture models, the role of rare species, and inferential challenges. Ecology 86:1143-1153. Download pdf.

Mao, C. X., R. K. Colwell, and J. Chang. 2005. Estimating species accumulation curves using mixtures. Biometrics 61:433-441. Download pdf.

Romdal, T. S., R. K. Colwell, and C. Rahbek. 2005. The influence of band sum area, domain extent and range sizes on the latitudinal mid-domain effect. Ecology 86:235-244. Download pdf.

Jetz, W., C. Rahbek, and R. K. Colwell. 2004. The coincidence of rarity and richness and the potential signature of history in centres of endemism. Ecology Letters 7:1180-1191. Download pdf.

Colwell, R. K. 2004. Biota 2: The biodiversity database manager. Sinauer Associates, Sunderland, MA. (Software and 880 p. Manual. Predecessor Biota 1 has more than 1000 users in 40 countries and 48 U.S. states.)

Colwell, R. K. 2004. EstimateS, Version 7: Statistical Estimation of Species Richness and Shared Species from Samples (Software and User's Guide). Freeware for Windows and Mac OS. (EstimateS has been downloaded more than 10,000 times by users in more than 100 countries. It is cited in nearly 250 publications.)

Colwell, R. K., C. X. Mao, and J. Chang. 2004. Interpolating, extrapolating, and comparing incidence-based species accumulation curves. Ecology 85 :2717-2727. Download pdf.

Koh, L. P., R. R. Dunn, N. S. Sodhi, R. K. Colwell, H. C. Proctor, and V. S. Smith. 2004. Species coextinctions and the biodiversity crisis. Science 305:1632-1634. Online Abstract. Online full text.

Longino, J., Coddington, J. A., and Colwell, R. K. 2002. The ant fauna of a tropical rainforest: estimating species richness three different ways. Ecology 83:689-702. Download pdf.

Gotelli, N., and Colwell, R. K. 2001. Quantifying biodiversity: Procedures and pitfalls in the measurement and comparison of species richness. Ecology Letters 4:379-391. Download pdf.

Colwell, R. K. 2000. Rensch's Rule crosses the line: Convergent allometry of sexual size dimorphism in hummingbirds and flower mites. American Naturalist 156:495-510. Download pdf.

Colwell, R, K. 2000. A barrier runs through it...or maybe just a river (Commentary). PNAS 97:13470-13472. Download pdf.

Colwell, R. K., and Lees, D. C. 2000. The mid-domain effect: geometric constraints on the geography of species richness. Trends in Ecology and Evolution 15:70-76. Download pdf. (Related software: RangeModel.)

Oliver, I., Pik, A., Britton, D., Dangerfield, J. M., Colwell, R. K., and Beattie, A. J. 2000. Virtual biodiversity assessment systems: the application of bioinformatics technologies to the accelerated accumulation of biodiversity information. BioScience 50:441-450.

Colwell, R. K., and Naeem, S. 1999. Sexual sorting in hummingbird flower mites. Annals of Entomological Society of America 92:652-659.

Chazdon, R. L., Colwell, R. K., and Denslow, J. S. 1999. Tropical tree richness and resource-based niches. Science 285:1459a. Download pdf.

Longino, J. T. and Colwell, R. K. 1998. Biodiversity assessment using structured inventory: Capturing the ant fauna of a lowland tropical rainforest. Ecological Applications 7:1263-1277. Download low resolution pdf. Download high resolution pdf.

Chazdon, R. L., R. K. Colwell, J. S. Denslow, & M. R. Guariguata. 1998. Statistical methods for estimating species richness of woody regeneration in primary and secondary rain forests of NE Costa Rica. Pp. 285-309 in F. Dallmeier and J. A. Comiskey, eds. Forest biodiversity research, monitoring and modeling: Conceptual background and Old World case studies. Parthenon Publishing, Paris. Download pdf.

Naskrecki, P., and R. K. Colwell. 1998. Systematics and host plant affiliations of hummingbird flower mites of the genera Tropicoseius Baker and Yunker and Rhinoseius Baker and Yunker (Acari: Mesostigmata: Ascidae). Thomas Say Publications in Entomology: Monographs. Entomological Society of America. 185 pp.

Colwell, R. K. 1995. Effects of nectar consumption by the hummingbird flower mite Proctolaelaps kirmsei on nectar availability in Hamelia patens. Biotropica 27: 206-217. Download pdf.

Colwell, R. K., and Coddington, J. A. 1994. Estimating terrestrial biodiversity through extrapolation. Philosophical Transactions of the Royal Society (Series B) 345:101-118. Download low resolution pdf. Download high resolution pdf. [Reprinted in D. L. Hawksworth, ed. Bio-diversity: Measurement and estimation. Chapman and Hall, London.] (Related software: EstimateS.)

Colwell, R. K., and Hurtt, G. C. 1994. Nonbiological gradients in species richness and a spurious Rapoport effect. American Naturalist 144:570-595. Download pdf. (Related software: RangeModel.)

Colwell, R. K. 1989. Hummingbirds of the Juan Fernandez Islands: natural history, evolution and population status. Ibis 131: 548-566. Download pdf.

Courses Taught

General Ecology (EEB 2244): A lecture and laboratory course principally for third and fourth year undergraduate majors in Biology, EEB, and related fields. Offered every Fall and Spring Semester. (I teach in the Fall Semester of even-numbered years.)

General Ecology (EEB 2244W): The writing component of EEB2244, offering students the opportunity to work one-on-one with an instructor to learn how to write effectively about scientific topics. (I teach in the Fall Semester of odd-numbered years.)

Population and Community Ecology (EEB 5301): An intensive graduate course in quantitative ecology, with lectures, discussions, and computer-based laboratory excercises. Offered in the Spring Semester of odd-numbered years.

Evolution and Ecology of Communities (EEB 5375): A topical course that focuses each time it is offered on a current growing point in quantitative and theoretical ecology or biogeography. Offered in the Spring Semester of even-numbered years.

Seminar in Biodiversity (EEB 5481): This weekly graduate research and presentation workshop, known for more than a decade for its supportive and constructive atmosphere, offers the opportunity for graduate students to present research plans, reports of work in progress, and full-length seminars on completed research projects to a friendly but critical audience of their peers. Offered every Fall Semester.

Current Graduate Students

Kellie M. Kuhn (USA), PhD Program: Spatio-temporal variation in an ant-plant interaction.

Johanna Elsensohn (USA): BS-MS Program in Conservation Biology

Previous Graduate Students

Alphabetical by surname, with current employment in parentheses

Institution awarding the degree:
UCB = University of California, Berkeley
UConn = University of Connecticut

Carol Baird, Ph.D., UCB (Executive Director, California Institute for Biodiversity, Moraga, California)

Rudi Berkelhamer, Ph.D., UCB (Associate Dean of Undergraduate Education, University of California, Irvine)

Elizabeth Braker, Ph.D., UCB (Associate Professor, Occidental College, Los Angeles, California)

Saul Cunningham, Ph.D., UConn (Team Leader, CSIRO, Canberra, Australia)

David S. Dobkin, Ph.D., UCB (Executive Director, High Desert Ecological Research Institute, and Executive Director, Greater Hart-Sheldon Conservation FundBend Oregon)

Robert R. Dunn, Ph.D., UConn (Associate Professor, North Carolina State University, Raleigh, North Carolina)

Eduardo R. Fuentes, Ph.D., UCB (Consultor Biodiversidad y Desarrollo, Chile; formerly United Nations Development Program, New York)

Lloyd Goldwasser, Ph.D., UCB (Visiting Associate Researcher,
Graduate School of Education and Department of Integrative Biology
University of California, Berkeley, and Senior Scientist, California Institute for Biodiversity, Moraga, California)

William Glanz, Ph.D., UCB (Associate Professor, Department of Biological Sciences, University of Maine, Orono)

Matthew Greenstone, Ph.D., UCB (Senior Research Entomologist, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Maryland)

Leon Hallacher, Ph.D., UCB (Professor, Department of Biology, University of Hawaii, Hilo)

Amy Jo Heyneman, Ph.D., UCB (Bainbridge Island College Advisory Service, Washington)

James H. Hunt, Ph.D., UCB (Professor Emeritus and former Chair, Department of Biology, University of Missouri-St. Louis; Visiting Professor of Biology and of Entomology and Faculty Associate of the Keck Center for Behavioral Biology, North Carolina State University)

Fabian Jaksic, Ph.D., UCB (Profesor Titular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile)

Anna Lovrien, M.S., UConn (Biology Teacher, John Marshall High School, Minneapolis, Minnesota) St Charles Secondary School
St. Charles, Minnesota

Tsitsi McPherson, M.S., Ph. D., UConn

Shahid Naeem, Ph.D., UCB (Professor and Chair, Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York)

Piotr Naskrecki, Ph.D., UConn (Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts )

Ariel Power, M.S., UCB (Research Associate, Forest Products Laboratory, University of California, Berkeley)

Margaret Race, Ph.D., UCB ( SETI Institute Principal Investigator, U. S. National Aeronautics and Space Administration, NASA SETI Institute, Mountain View, California)

Thiago F. Rangel, Ph.D., UConn (Assistant Professor, Departamento de Ecologia, ICB, Universidade Federal de Goiás, Goiânia, GO, Brazil)

Carlos Robles, Ph.D., UCB (Oustanding Professor, Department of Biological Sciences, California State University, Los Angeles, California)

George R. Roderick, Ph.D., UCB (William Muriece Hoskins Chair in Chemical and Molecular Entomology, Department of Environmental Science, Policy, and Management; Chair, Division of Organisms & Environment; and Faculty Curator, Essig Museum of Entomology, University of California, Berkeley)

Sacha Spector, Ph.D., UConn ( Director of Conservation Science, Scenic Hudson, Poughkeepsie, NY, and Reseach Associate, Center for Biodiversity and Conservation, American Museum of Natural History, New York )

Martha L. Stout, Ph.D., UCB (Retired. Formerly Senior Scientist, Office of Wetlands Protection, U. S. Environmental Protection Agency, Washington, DC)

Juan A. Torres, Ph.D., UCB (Professor, Department of Biology, University of Puerto Rico, San Juan, Puerto Rico; Deceased 2004)