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Todd Freeberg



Animal Behavior and Animal Communication

I am interested in vocal communication, and have focused my studies thus far on bird species, using a combination of field and laboratory approaches. My research seeks to understand the development, function, and evolution of vocal signals and signaling.

Research statement

Research in the lab is aimed towards understanding relationships between social organization and systems of vocal communication. Studies have focused on the social transmission of behavioral traditions related to courtship and mating in brown-headed cowbirds, and on the possible meanings and learning of a complex vocalization in Carolina chickadees. Whereas most studies of bird song learning assess only the song, I try to focus my work on not just the song, but also on the signaler and the social context in which the signals are produced. I also seek to take comparative approaches in the research, to try to uncover genetic, ecological, and social influences on systems of vocal signals.


  • *Bartmess-LeVasseur, J., Branch, C. L., *Browning, S. A., *Owens, J. L., & Freeberg, T. M. (2010). Predator stimuli and calling behavior of Carolina chickadees (Poecile carolinensis), tufted titmice (Baeolophus bicolor), and white-breasted nuthatches (Sitta carolinensis). Behavioral Ecology & Sociobiology, 64, 1187-1198.
  • B?rzi?š, A., Krama, T., Krams, I., Freeberg, T. M., Kivleniece, I., Kullberg, C., & Rantala, M. J. (2010). Mobbing as a tradeoff between safety and reproduction in a songbird.Behavioral Ecology, 21, 1054-1060.
  • Freeberg, T. M. (2010) Cultural inheritance of signals. In M. D. Breed and J. Moore (Eds.), Encyclopedia of Animal Behavior, Volume 1, (pp. 435-439). Oxford: Academic Press.
  • Lucas, J. R., & Freeberg T. M. (2010) Communication: an overview. In M. D. Breed and J. Moore (Eds.), Encyclopedia of Animal Behavior, Volume 1, (pp. 337-339). Oxford: Academic Press.
  • Mahurin, E. J., & Freeberg, T. M. (2009). Chick-a-dee call variation in Carolina chickadees and recruiting flockmates to food. Behavioral Ecology, 20, 111-116.
  • Freeberg, T. M., & Lucas, J. R. (2009). Pseudoreplication is (still) a problem. Journal of Comparative Psychology, 123, 450-451.
  • Freeberg, T. M.  (2008). Complexity in the chick-a-dee call of Carolina chickadees (Poecile carolinensis): associations of context and signaler behavior to call structure.Auk, 125, 896-907.
  • Freeberg, T. M. & Harvey, E. M. (2008). Group size and social interactions are associated with calling behavior in Carolina chickadees, Poecile carolinensisJournal of Comparative Psychology, 122, 312-318.
  • Freeberg, T. M., King, A. P., & West, M. J. (2008). Behavioral compatibility and reproductive outcomes in two distant populations of captive brown-headed cowbirds (Molothrus ater). Journal of Comparative Psychology, 122, 437-440.
  • Schwartz, J. J., & Freeberg, T. M. (2008). Acoustic Interaction in Animal Groups: Signaling in Noisy and Social Contexts. Journal of Comparative Psychology, 122, 231-234.
  • Freeberg, T.M., White, D.J. (2006).  Social traditions and the maintenance and loss of geographic variation in mating patterns of brown-headed cowbirds.  International Journal of Comparative Psychology, 19, 206-222. [2006 publication date, but did not appear until 2007]
  • Freeberg, T. M., Baker, M. C., Bloomfield, L. L., Charrier, I., Gammon, D. E., Hailman, J. P., Lee, T. T.-Y., Lucas, J. R., Mennill, D. J., & Sturdy, C. B. (2007). Complexities in vocal communication. In K. Otter (Ed.), Ecology and Behavior of Chickadees and Titmice: An Integrated Approach, (pp. 235-240), Oxford: Oxford University Press.
  • Harvey, E. M. & Freeberg, T. M. (2007). Behavioral consistency in a changed social context in Carolina chickadees. [Special Issue on ‘Animal Cognition and Behavior’]Journal of General Psychology, 134, 229-245.
  • Lucas, J. R. & Freeberg, T. M. (2007). “Information” and the chick-a-dee call: communicating with a complex vocal system. In K. Otter (Ed.), Ecology and Behavior of Chickadees and Titmice: An Integrated Approach, (pp. 199-213). Oxford: Oxford University Press.
  • Lucas, J. R., Freeberg, T. M., Long, G. R., & Krishnan, A. (2007). Seasonal variation in avian auditory evoked responses to tones: a comparative analysis of Carolina chickadees, tufted titmice, and white-breasted nuthatches. Journal of Comparative Physiology, A, 193, 201-215.
  • Owens, J. L. & Freeberg, T. M. (2007). Variation in chick-a-dee calls of tufted titmice,Baeolophus bicolor: note type and individual distinctiveness. Journal of the Acoustical Society of America, 122, 1216-1226.
  • Freeberg, T. M. (2006). Social complexity can drive vocal complexity: group size influences vocal information in Carolina chickadees. Psychological Science, 17, 557-561.
  • Lucas, J. R, Freeberg, T. M., Egbert, J., & Schwabl, H. (2006). Fecal corticosterone, body mass, and caching rates of Carolina chickadees (Poecile carolinensis) from disturbed and undisturbed sites. Hormones & Behavior, 49, 634-643.
  • Clucas, B.A., Freeberg, T.M., & Lucas, J.R. (2004). Chick-a-dee call syntax, social context, and season affect vocal responses of Carolina chickadees (Poecile carolinensis). Behavioral Ecology & Sociobiology, 57, 187-196.
  • Freeberg, T.M. (2004). Social transmission of courtship behavior and mating preferences in brown-headed cowbirds, Molothrus ater. Learning and Behavior, 32, 122-130.
  • Schrag, B., Freeberg, T.M., & Anestidou, L. (2004). The Gladiator Sparrow: ethical issues in behavioral research on captive populations of wild animals – A case study with commentaries exploring ethical issues and research on wild animal populations. Journal of Science and Engineering Ethics, 10, 717-734.
  • Freeberg, T.M., Lucas, J.R., Clucas, B.A. (2003). Variation in chick-a-dee calls of a Carolina chickadee population, Poecile carolinensis: Identity and redundancy within note types. Journal of the Acoustical Society of America 113, 2127-2136.
  • Freeberg, T.M., Lucas, J.R. (2002). Receivers respond differently to chick-a-dee calls varying in note composition in Carolina Chickadees (Poecile carolinensis). Animal Behaviour 63, 837-845.
  • Lucas, J. R., Freeberg, T. M., Krishnan, A., & Long, G. (2002) A comparative study of avian auditory brainstem responses: correlations with phylogeny and vocal complexity, and seasonal effects. Journal of Comparative Physiology, A 188, 981-992.
  • Freeberg, T. M., West, M. J., King, A. P., Duncan, S. D., & Sengelaub, D. R. (2002) Cultures, genes, and neurons at the nexus of female influence on the development of brown-headed cowbird (Molothrus ater) vocal communication. Journal of Comparative Physiology, A 188, 993-1002.

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