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Welcome to the McCain Lab

Department of Ecology & Evolutionary Biology
Museum of Natural History
University of Colorado Boulder

We use mountains as natural experiments to study biodiversity, biogeography, biotic interactions, conservation, ecological theory, global change, montane ecology, and range limits.

We love the world's biological wonders and our research encompasses many types of organisms from mammals and other vertebrates to carrion beetles and lichens.

Who are we?

PI: Dr. Christy M. McCain

Associate Professor & Curator of Vertebrates

Dept. of Ecology & Evolutionary Biology
CU Natural History Museum
Campus Box 265 UCB, University of Colorado, Boulder, CO 80309

Curriculum Vitae

Current Students & Researchers

Anna Chinn

Masters Student

Museum & Field Studies Program, CU Natural History Museum

Research Interests: Museum Collection Management, Collections Databases, Identification accuracy

Grant Vagle

PhD Student

IQBio Program, Dept. of Ecology & Evolutionary Biology

Research Interests: Montane Mammals

Ben Shipley

Undergraduate Honors Student

Dept. of Ecology & Evolutionary Biology
Dept. of Geography

Research Interests: Montane Biodiversity & Impacts of Deforestation

Tyler Streb

Undergraduate Honors Student

Dept. of Ecology & Evolutionary Biology

Research Interests: Carrion Beetle Biology & Distribution

Richard Dyer

Undergraduate Student

Dept. of Computer Science
Dept. of Applied Math

Lab Interests: Spiders & Insects of the Rockies

Andy Hicks


Dept. of Ecology & Evolutionary Biology
CU Natural History Museum

Research Interests: Beetles, Leafhoppers, & Natural History of Insects

Hazel McCain

Lab Mascot

Research interests: all smells and mammals, particularly canids, homo sapiens, and chipmunks

Past Students & Researchers

Dr. Kevin Bracy Knight

PhD in Ecology & Evolutionary Biology

Current Position: Conservation Scientist at the Environmental Defense Fund

Research Interests: Conservation Biology, Conservation Triage, Primate Conservation

Dr. Tim Szewczyk

PhD in Ecology & Evolutionary Biology

Current Position: Postdoc at the University of New Hampshire

Research Interests: Montane Ants, Computational Biology, Conservation Biology

More Previous Students & Research Assistants

Tara Menne, Museum and Field Studies Certificate Student 2010-2014
Hayden Gardner, EBIO Undergraduate Student, Honors Student (Magna Cum Laude), Research Assistant 2010-2012
John Hackemer, EBIO Undergraduate Student, Honors Student (Magna Cum Laude), Research Assistant 2010-2012
Emma Shubin, EBIO & Music Undergraduate Student, Honors Student (Magna Cum Laude), Research Assistant 2011-2013
Daniela Ramos, EBIO Undergraduate Student, Honors Student (Cum Laude), Research Assistant 2011-2013
Richard Parkhill, EBIO Undergraduate Student, Independent Research, Research Assistant 2010-2012
Holly D'Oench, EBIO Undergraduate Student, Independent Research, Research Assistant 2012-2016
Emily Monk, EBIO Undergraduate Student, Independent UROP Research 2015
Kathryn Feldmann, EBIO Undergraduate Student, Research Assistant 2016-2017
Angela Knerl, EBIO Undergraduate Student, Research Assistant 2010-2014
Will Winship, EBIO Undergraduate Student, Research Assistant 2011
Mark McGregor, EBIO Undergraduate Student, Research Assistant 2008-2009
Helen Van Damm, EBIO Undergraduate Student, Research Assistant 2008
Brian Heinold, Research Assistant 2016
Heather Taylor-Smith, Research Assistant 2011-2013
Sadie Yurista, Research Assistant 2012-2013
Mike Schmidtke, Research Assistant 2012
Jake Harris, Research Assistant 2010-2012
Justin Bondensen, Research Assistant 2012
Alisha Wainwright, Research Assistant 2011
Cullen Dembowski, Research Assistant 2010
Heather Hansen, Research Assistant 2009-2010
Justin Freeman, Research Assistant 2010

Previous Postdocs & Researchers

Dr. Sarah King, Postdoctoral Researcher 2010-2013

Dr. Kevin Hinson, Postdoctoral Researcher 2015


   The need to document and to understand the mechanisms producing distributional patterns is becoming increasingly urgent as biodiversity is being threatened at unprecedented rates due to human impacts. To develop the most effective methods to preserve species, we need a better understanding of the mechanisms involved in creating and maintaining biodiversity, setting range limits, and limiting populations. I exploit mountain systems as natural experiments with the overarching goal to contribute to the development of quantitative, testable theories applicable to both the advancement of ecology and the improvement of our conservation strategies.

   My current research program has two primary foci: (1) using trends in montane diversity to elucidate general, repeatable relationships with potential drivers (Fig. 1); and testing those general trends for the underlying mechanisms in empirical studies, including probing the strength of various climate-diversity mechanisms and biotic interactions (Fig. 2). (2) how habitat modification and climate change are and will influence montane diversity, range limits, and populations to improve our conservation strategies (Fig. 3).

Global Mountain Research

   Mountains are hotspots of biodiversity, harboring the majority of the world's rare, endangered, and endemic species. When I began studying elevational diversity in the late 1990s, the paradigm was diversity decreased as elevation increased regardless of taxa. But it has become abundantly apparent from empirical studies and meta-analyses of the best sampled elevational gradients across the world that (1) there are a variety of elevational diversity patterns; (2) maximum diversity at middle elevations is the most common pattern, which is particularly uniform in certain clades of vertebrates and insects; (3) much of this variation is best described by contemporary climate based on multivariate tests of theory; and, importantly, (4) these patterns are directly tied to the underlying and distinct physiological and ecological niches of each clade (Fig. 1). This compiled series of global elevational gradients is a wealth of information on which we continue to build quantitative theory and explore conservation strategies.

Empirical Mountain Research

Project Mammal: "Diversity and Climate Change: using elevational gradients to uncover processes underlying mammalian species distributions." (McCain: NSF DEB 0949601). This study involves trapping mammals along four elevational gradients in Colorado at 32 sites to assess current distributions and population sizes and compare these to historical distributions. The main thrusts are two fold--(1) assess the influence of anthropogenic climate change on mammal distributions in the southern Rocky Mountains, and (2) detect the direct (e.g., physiological) versus indirect (e.g.,food resources) impacts of climate variables on mammalian diversity and distributions.

Project Arthropod: Along these four elevational gradients we are also assessing the diversity, abundance and distributional patterns of ants, all beetles, carrion beetles, grasshoppers, bees & wasps, and centipedes & millipedes with collaboration from many entomologists and invertebrate biologists. For several of these groups, we are also exploring the impacts of climate change and habitat modification in the CO Rockies. (McCain: NSF DEB 0949601, McCain: NPS). For a more detailed overview of this project, see our  Poster from the Entomology Society of America 2017. FYI I love carrion beetles, they exhibit some of the coolest biology on the planet. If you are interested in the carrion beetles of Colorado, see our  KEY.

Project Lichen: Dimensions of Biodiversity: "Biodiversity gradients in obligate symbiotic organisms: A case study in lichens in a global diversity hotspot" (Tripp, Lendemer, Kane & McCain: NSF 1542639). Lichens are in their infancy of our understanding of their montane diversity patterns, and relationships to climate or other potential drivers. Since lichens are an obligate symbiotic relationship among fungi, algae, cyanobacteria, and sometimes a yeast, we are using replicated elevational gradients along the length of the Appalachians to examine the role of individual partners in setting range limits of lichen species, among many other genomic, phylogenetic, and anthropogenic influences in the Appalachians. For more detail on this project see  Erin Tripp's website.

Global Change Research

   As mentioned above, our lab is conducting various empirical research studies in the Rockies to examine how species ranges are changing with warming temperatures and variation in precipitation. We are and have been building theory about how organisms will respond to our rapidly changing climate. For example, montane precipitation changes may amplify the extinction risks tenfold compared with the effects of warming alone (Fig. 3a; McCain & Colwell 2011). More recently using population simulation models, we detected that the frequency and magnitude of population peaks and troughs greatly impact the accuracy of our climate change response measurements (both overestimating and underestimating responses; McCain et al. 2016).

   We are also interested in how traits of species (e.g., activity patterns, microhabitat use, heterothermy), influence their responses to climate change. For example, among mammals in North America both the larger-bodied species and the noctural and diurnal species are responding much more uniformly to warming temperatures than are small mammals (less than 100 g) and those that have flexibility in their activity times (Fig. 3b; McCain & King 2016). We are currently working to extend these results to studies on trait differences in the mammals and beetles in empirical heterogeneous, warming climates.


Google Scholar Profile

Beck, J., Rudlinger, C. M. and McCain, C. M. 2017. Is the ecological belt zonation of the Swiss Alps relevant for moth diversity and turnover? Acta Oecologia 80: 1-7.

Beck, J., McCain, C. M., Axmacher, J.C., Ashton, L.A., Bartschi, F., Brehm, G., Choi, S.-W., Cizek, O., Colwell, R.K., Fiedler, K., Francois, C.L., Highland, S., Holloway, J.D., Intachat, J., Kadlec, T., Kitching, R.L., Maunsell, S.C., Merckx, T., Nakamura, A., Odell, E., Sang, W., Toko, P.S., Zamecnik, J., Zou, Y. & Novotny, V. 2017. Elevational species richness gradients in a hyperdiverse insect taxon: a global meta-study on geometrid moths. Global Ecology and Biogeography 26: 412-424.

Colwell, R.K., Gotelli, N.J., Ashtone, L.A., Beck, J., Brehm, G., Fayle, T.M., Fiedler, K., Forister, M.L., Kessler, M., Kitching, R.L., Klimes, P., Kluge, J., Longino, J. T., Maunselle, S.C., McCain, C.M., Moses, J., Noben, S., Sam, K., Sam, L, Shapiro, A.M., Wang, X. and V. Novotny. 2016. Midpoint attractors and species richness: Modeling the interaction between environmental drivers and geometric constraints. Ecology Letters 19: 1009-1022. [PDF]

Szewczyk, T.* and McCain, C. M. 2016. A systematic review of global drivers of ant elevational diversity. PlosONE 10: e0155404. [PDF]

McCain, C. M., Szewczyk, T.*, K. Bracy Knight*. 2016. Population variability complicates the accurate detection of climate change responses. Global Change Biology 22: 2081-2093. [PDF]

McCain, C. M. and J. Beck. 2016. Species turnover in vertebrate communities along elevational gradients is idiosyncratic and unrelated to species richness. Global Ecology and Biogeography 25: 299-310. [PDF]

King, S. R. B. and McCain, C. M. 2015. Reithrodontomys megalotis and R. montanus can be robustly discriminated using cranial osteology and external characteristics within age classes. Proceedings of the Biological Society of Washington 128: 1-10. [PDF]

McCain, C. M. and S. R. B. King. 2014. Body size and activity times mediate mammalian responses to climate change. Global Change Biology 20: 1760-1769. [PDF]

Botero, C.A., Dor, R. McCain, C.M., and Safran, R.J. 2014. Environmental harshness is positively correlated with intraspecific divergence in mammals and birds. Molecular Ecology 23: 259-268. [PDF]

Graham, C. H., A. C. Carnaval, C. D. Cadena, K. R. Zamudio, T. E. Roberts, J. L. Parra, C. M. McCain, R. C. K. Bowie, C. Moritz, S. B. Baines, C. J. Schneider, J. VanDerWal, C. Rahbek, K. H. Kozak, and N. J. Sanders. 2014. The origin and maintenance of montane biodiversity: integrating evolutionary and ecological processes. Ecography 37: 711-719. [PDF]

Gaston, K. J., McCain, C. M., and Lyons, S. K. 2014. Abundance and Distributions. Pages 400-402 in Foundations of Macroecology (eds. Smith, F. A., Gittleman, J. L. and Brown, J. H.). University of Chicago Press.

McCain, C. M. 2014. Introduction to Geographic ranges of North American terrestrial mammals (Anderson 1977). Page 416 in Foundations of Macroecology (eds. Smith, F. A., Gittleman, J. L. and Brown, J. H.). University of Chicago Press.

McCain, C. M. 2014. Introduction to The latitudinal spans of seaweed species and their patterns of overlap (Pielou 1977). Page 465 in Foundations of Macroecology (eds. Smith, F. A., Gittleman, J. L. and Brown, J. H.). University of Chicago Press.

McCain, C. M. 2014. Introduction to On the relationship between abundance and distribution of species (Brown 1984). Page 509 in Foundations of Macroecology (eds. Smith, F. A., Gittleman, J. L. and Brown, J. H.). University of Chicago Press.

McCain, C. M. and K. Bracy Knight.* 2013. Is Rapoport's Rule pervasive on mountains? Global Ecology and Biogeography 22: 750-759. [PDF]

Hawkins, B.A. McCain, C.M., Davies, T.J., Ackerly, D.D., Anacker, B., Buckley, L.B., Cornell, H.V., Damschen, E.I., Grytnes, J.-V., Harrison, S.P., Kraft, N.J.B., and Stephens, P.R. 2012. Different evolutionary histories underlie congruent species richness gradients of birds and mammals. Journal of Biogeography 9:825-841. [PDF]

Cadena, C.D., Kozak, K.H., Gomez, J.P., Parra, J.L., McCain, C.M., Bowie, R.C.K., Carnaval, A.C., Moritz, C., Rahbek, C., Roberts, T., Sanders, N., Schneider, C., VanDerWal, J., Zamudio, K., and Graham, C.H. 2012. Latitude, elevational climatic zonation, and speciation in New World vertebrates. Proceedings of the Royal Society B-Biological Sciences 279:194-201. [PDF]

McCain, C. M. 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. [PDF]

Fierer, N., McCain, C. M., Meir, P., Zimmerman, M., Rapp, J. M., Silman, M. R., and Knight, R. 2011. Microbial elevational diversity does not follow the biogeographical trends of plants and animals. Ecology 92: 797-804. [PDF]

McCain, C. M. 2010. Global analysis of reptile elevational diversity. Global Ecology and Biogeography 19:541-553. [PDF]

McCain, C. M., and N. J. Sanders. 2010. Metabolic theory and elevational diversity of vertebrate ectotherms. Ecology 91:601-609. [PDF]

McCain, C. M. and J. A. Grytnes. 2010. Elevational gradients in species richness. Encyclopedia of Life Sciences, John Wiley & Sons, Inc.; 13 pp. [Invited & Peer-reviewed] [PDF]

Buckley, L.B., Davies, T.J., Ackerly, D.D., Kraft , N.J.B., Harrison, S.P., Anacker, B., Cornell, H.V., Damschen, E.I., Grytnes, J.-V., Hawkins, B.A. McCain, C.M., Stephens, P.R. and Wiens, J.J. 2010. Mammalian climate-diversity gradients: An inevitable product of aggregating clades with distinct evolutionary histories? Proceedings of the Royal Society of London 277:2131-2138. [PDF]

Smith, F.A., Boyer, A.G., Brown, J.H., Costa, D.P., Dayan, T., Ernest, S.K.M., Evans, A.R., Fortelius, M., Gittleman, J.L., Hamilton, M.J., Harding, L.E., Lintulaakso, K., Lyons, S.K., McCain, C.M., Okie, J.G., Saarinen, J.J., Sibly, R.M., Stephens, P.R., Theodor, J., and M.D. Uhen. 2010. The evolution of maximum body size in terrestrial mammals. Science 330:1216-1219. [PDF]

Wiens, J.J, Ackerly, D.D., Allen, A.P., Anacker, B.L., Buckley, L.B., Cornell, H.V., Damschen, E.I. Davies, T.J., Grytnes, J.-A., Harrison, S.P., Hawkins, B.A., Holt, R.D., McCain, C.M. & Stephens, P.R. 2010. Niche conservatism as an emerging principle in ecology and conservation biology. Ecology Letters 13:1310-1324. [PDF]

McCain, C. M. 2009. Vertebrate range sizes indicate that mountains may be ‘higher’ in the tropics. Ecology Letters 12:550-560. (Recommended in Faculty of 1000) [PDF]

McCain, C. M. 2009. Global analysis of bird elevational diversity. Global Ecology and Biogeography 18:346-360. [PDF]

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

McCain, C. M. 2007. Area and mammalian elevational diversity. Ecology 88:76-86. [PDF]

McCain, C. M. 2007. Could temperature and water availability drive elevational diversity? A global case study for bats. Global Ecology and Biogeography 16:1-13 & Cover. [PDF]

Dunn, R. R., C. M. McCain, and N. J. Sanders. 2007. When does diversity fit null model predictions? Scale and range size mediate the mid-domain effect. Global Ecology and Biogeography 16:305-312. [PDF]

Mittelbach, G.G., D. Schemske, H.V. Cornell, A.P. Allen, J. Brown, M. Bush, S.P. Harrison, A. Hurlbert, N. Knowlton, H.A. Lessios, C. M. McCain, A.R. McCune, L.A. McDade, M.A. McPeek, T.J. Near, T.D. Price, R.E. Ricklefs, K. Roy, D.F. Sax, D. Schluter, J. M. Sobel, and M. Turelli. 2007. Evolution and the latitudinal diversity gradient: speciation, extinction, and biogeography. Ecology Letters 10:315-331. [PDF]

Grytnes, J. A. and C. M. McCain. 2007. Elevational trends in biodiversity. Pages 1-8 in Encyclopedia of Biodiversity (S. Levin, editor), Elsevier, Inc. [Invited & Peer-reviewed]. [PDF]

McCain, C. M., R. M. Timm, and M. Weksler. 2007. Sigmodontomys aphrastus: Redescription, taxonomic comparison, and natural history. Proceedings of the Biological Society of Washington 120:117-136. [PDF]

McCain, C. M. 2006. Do elevational range size, abundance, and body size patterns mirror those documented for geographic ranges? A case study using Costa Rican rodents. Evolutionary Ecology Research 8:435-454. [PDF]

McCain, C. M. 2005. Elevational gradients in diversity of small mammals. Ecology 86:366-372. [PDF]

McCain, C. M. 2004. The mid-domain effect applied to elevational gradients: species richness of small mammals in Costa Rica. Journal of Biogeography 31:19-31. [PDF]

McCain, C. M. 2003. North American desert rodents: a test of the mid-domain effect in species richness. Journal of Mammalogy 84:967-980. [PDF]

McCain, C. M. 2001. First evidence of giant anteaters (Myrmecophaga tridactyla) in Honduras. Southwestern Naturalist 46:252-254. [PDF]


Mammalogy (EBIO 4760/5760; MUSM 5760)
Taught in Even Falls: next in Fall 2018
Syllabus & Schedule (2016)

Creative Conservation Messaging (EBIO 6100/6110)
Taught in Even Springs: next in Spring 2018
Syllabus & Schedule (2018)

Mountain Ecology & Conservation (EBIO 3170)
Taught in 2014: next in TBD
Syllabus & Schedule (2014)

Other Previous Classes: Field Methods in Zoology & Botany (MUSM 5795, EBIO 4795/5795, & ENVS 4795); Biogeography: Foundations & Frontiers (grad seminar: EBIO 6100)

Want to Join the Lab?

The McCain Lab is dedicated to including and encouraging participation of all peoples across genders, ethnicities, cultures, religions, physical abilities, ages, sexual orientations, political viewpoints, and gender identities.

Graduate Students

I am currently looking for motivated and enthusiastic graduate students to join the lab to pursue either a Masters or a Doctoral degree in the Department of Ecology and Evolutionary Biology (EBIO) or the Museum & Field Studies Program (MFS). I encourage students to pursue research ideas related to mine on any taxonomic group. Please see my research and publications for specifics on my research interests.

I think success in graduate school is dependent on both developed skills and intangibles. Some necessary skills are logical thinking, quantitative ability, intellectual creativity, hard work, and independence. Intangibles include excitement about biology, dogged determination, and taking joy from biological beauty.

Support is available in the form of fellowships and teaching, curatorial and research assistantships, but all students applying to work with me are encouraged to apply for outside funding. Two options are NSF pre-doctoral fellowships and EPA STARR fellowships.

If interested, please email me a CV including GPA and GRE precentiles, a brief statement of research interests & academic goals (~1 page), and contact information for three references. Competition for graduate positions in my lab is keen, as I usually 20-30 applicants per year. The EBIO application deadline is Dec. 1st, for more information visit our Graduate website. The MFS deadline is Jan. 15th, for more information visit the MFS website. These deadlines vary for international students and sometimes change year to year, so please check the admissions websites carefully. There is also funding for a weekend visit and graduate application training for interested applicants from underrepresented groups in the sciences, see the ColoradoAdvantage program, and the deadline for that program is Sept. 19th.

Undergraduate Students

CU offers several opportunities for undergraduate research funding, I encourage all undergraduates interested in research to apply for these grants and fellowships.

We often have opportunities helping in the lab on the elevational diversity of Rocky Mountain insects, but currently these are only volunteer positions. For our summer mammal trapping, we also take motivated volunteers as well as applicants for paid positions.

If you are looking for research experience, there are opportunities for independent projects and honors theses. I have preference for students who have taken my classes, since we have already interacted extensively. Regardless, if you have an research idea you would like to pursue, please email me and include a description of your project idea, your resume with classes, grades, and research experience. Be aware that I do not supervise honors theses for projects for which the data have already been collected (e.g., in a study abroad program).

Vertebrate Collection

CU Museum of Natural History

See our Museum website for more detailed information about collections, loans, policies, and questions.
All vertebrate data are publically available on ARCTOS and GBIF
122,787 specimens total

Amphibians & Reptiles: 65,744 specimens
Birds:                                 14,519 specimens
Fishes:                              25,518 specimens (~2272 lots)
Mammals:                        17,006 specimens

Vertebrates Staff

Christy McCain


Emily Braker
Collection Manager


Please consider helping us fund the protection, conservation, and research on the CU Vertebrates Collection! All donations are tax deductible.

We thank all of the wonderful, generous donors so far who have made our mammal cabinetry upgrade so successful!

Simulation Programs

Computer coding for testing various diversity & distribution hypotheses

Our lab uses a diversity of quantitative, simulations, and statistical methods to test our theoretical and empirical hypotheses. Some of those mini-programs we built to run in Excel using Visual Basic, and have made available for other's use. Unfortunately, we do not have the staff to continually update these for each new version of Excel. So they might not always work for every computer and set of software.

Mid-Domain Null
I developed a program for generating null model predictions for empirical diversity patterns called Mid-Domain Null, a Monte Carlo simulation procedure, which I wrote in Visual Basic for Excel (McCain 2004). This program simulates species richness curves based on empirical range sizes or range midpoints within a bounded domain based on the analytical-stochastic models of Colwell (1999) and Colwell & Hurtt (1994). Mid-Domain Null allows for sampling with or without replacement from empirical range sizes or midpoints. The program is designed to run thousands of Monte Carlo simulations in a single session and offers various outputs including species richness curves, 95% simulation prediction curves, randomized data, among others. The program and accessory files are downloadable here: Mid-Domain Null add-on, help filesample.

Beta Simulations
I developed a program for three null model simulations (hard boundaries, soft boundaries and no boundaries) for turnover simulations. This was written in Visual Basic for Excel for a paper with Jan Beck (McCain & Beck 2016). To download the program as an Excel spreadsheet with functional module button, click here. The program works very similarly to the Mid-domain Null program, so see the help file and sample above.