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  • College of Natural and Agricultural Sciences

Chris Clark


for Christopher W Clark, go here.

Assistant Professor of Biology
Office: 3344 Spieth Hall (Biology)
Office phone: 951-827-3646
Facsimile:  951-827-4286


Degree:  Ph.D., University of California, Berkeley, May 2009.

Profile in Google Scholar

Clark Lab homepage

My laboratory studies courtship displays, how feathers and wings produce sound, and bird flight biomechanics, using hummingbirds as a model system.

My PhD was on hummingbird tail morphology and how tail feathers elongated by sexual selection affect flight performance. Along the way, I started a minor side project in which I figured out that Anna's Hummingbird produces a loud sound with its tail-feathers during its courtship dive. This unexpected finding 'deflected' my research trajectory onto the mechanics of how feathers produce sound. In the 'bee' hummingbird clade, there has been rapid divergence in male tail morphology, and males produce unique sounds with their unique tail morphologies. For some examples, see my youtube channel. Studying how they produce sounds with their tail-feathers has revealed a range interesting questions. Hummingbird courtship displays are fantastic athletic feats, an example of extreme flight performance of interest to flight biomechanics.

My lab has high-speed cameras and sound recording equipment for both field and lab work. I am building an aeroacoustic wind tunnel with a 18" x 24" working section that will be capable of flying hummingbirds and other small birds.

Current and recent projects include:

  • Wind tunnel tests of feathers to determine the physical mechanisms by which they produce sound, both in Hummingbirds (Clark et al 2011, 2013a, b) and non-hummingbirds (Clark and Prum in prep)
  • Field manipulations of wild birds to determine which tail-feathers produce sound (Clark and Feo 2008, 2010, Feo and Clark 2010)
  • High-speed video of courtship displays of wild hummingbirds (see youtube channel link above).
  • Assisted Patricia Brennan in studying the explosive erections of duck penises.
  • Hovering and forward flight mask respirometry of hummingbirds in a wind tunnel.
  • Evolution of courtship displays of the 'bee' hummingbirds.
  • Field work (for recording courtship displays): Costa Rica, Bahamas, Cuba, Guatemala, Mexico, Colombia, Ecuador, Chile, Uganda, Texas, and of course, California.

I also participate in IDEA, the UCR Institute for the Development of Educational Applications.

Some Representative Publications....
  • Clark, C. J., Elias, D. O., Girard, M. B. and Prum, R. O. Forthcoming. Structural resonance and mode of flutter of hummingbird tail feathers. J Exp Biol, accepted May 2013.
  • Clark, C. J., Elias, D. O., and Prum, R. O. Forthcoming. Hummingbird feather sounds are produced by aeroelastic flutter, not vortex-induced vibration. J. Exp Biol, accepted May 2013.
  • Clark, C. J, Feo, T. J. and van Dongen, W. 2013. Sounds and courtship displays of the Peruvian Sheartail, Chilean Woodstar, Oasis Hummingbird, and a hybrid male Peruvian Sheartail x Chilean Woodstar. Condor, 115: 560-577.
  • Clark, C. J. 2012. The role of power versus energy in courtship: what is the "energetic cost" of a courtship display? Anim. Behav., 84: 269-277.
  • Clark, C. J., Elias, D., and Prum, R. O. 2011. Aeroelastic flutter produces hummingbird feather songs. Science, 333: 1430-1433.
  • Clark, C. J. 2011. Wing, tail, and vocal contributions to the complex signals of a courting Calliope Hummingbird. Curr. Zool, 57: 187-196.
  • Feo, T. J. and Clark, C. J. 2010. The displays and mechanical sounds of the Black-chinned Hummingbird (Trochilidae: Archilochus alexandri). Auk, 127: 787-796.
  • Clark, C. J. and Dudley, R. 2010. Hovering and forward flight energetics in Anna's and Allen's Hummingbirds. Physiol. Biochem. Zool. 83: 654-662. DOI: 10.1086/653477
  • Brennan, P. L. R., Clark, C. J. and Prum, R. O. 2010. Explosive eversion and functional morphology of the waterfowl penis supports sexual conflict in genitalia. Proc. R. Soc. Lond. B, 277: 1309-1314. DOI: 10.1098/rspb.2009.2139.
  • Clark, C. J. and Feo, T. J. 2010. Why do Calypte hummingbirds "sing" with both their tail and their syrinx? An apparent example of sexual sensory bias. Am. Nat., 175: 27-37.
  • Clark, C. J. 2009. Courtship dives of Anna's Hummingbird offer insights into flight performance limits. Proc. R. Soc. Lond. B. 276: 3047-3052.
  • Clark, C. J. and Dudley, R. 2009. Flight costs of long, sexually selected tails in hummingbirds. Proc. R. Soc. Lond. B. 276: 2109-2115.
  • Clark, C. J. 2008. Fluttering wing feathers produce the flight sounds of male streamertail hummingbirds. Biology Letters, 4: 341-344.
  • Clark, C. J. and Feo, T. J. 2008. The Anna's Hummingbird chirps with its tail: a new mechanism of sonation in birds. Proc. R. Soc. Lond. B. 275: 955-962.

    (click here for my CV)

    • Winter 2014: Biology 161B, Comparative Vertebrate Anatomy.