Karl S. Berg, Ph.D.

Contact Information

Associate Professor
Office: BLHBS 1.832
Phone: (956) 882-5049
Email: karl.berg@utrgv.edu 
Lab: https://www.utrgv.edu/avianecology 

Currently Teaching

  • BIOL 4432 - Animal Behavior
  • BIOL 6385 - Graduate Research
  • BIOL 7300 - Thesis I


  • PhD, Neurobiology, 2011
  • MS, Biological Sciences, 2004
  • BBA, Accounting, 1989

Areas of Expertise

  • Animal Behavior
  • Ornithology
  • Behavioral Ecology


Vocal imitation is a complex social behavior required for spoken language, but also found in select groups of mammals and birds. Parrots are among the most prolific of vocal linguists but have been aloof in nature. How does their bizarre ability to mimic human speech patterns in captivity benefit individuals in nature? Current work addresses such questions in a wild parrot population that has been meticulously marked and studied for decades. Social environment can have a profound influence on early cognitive foundations, but this depends on when sensory abilities emerge in juveniles and the types of social stimuli available. Objectives are to: 1) quantify natural variation in a suite of early developmental milestones with links to learning and cognition; 2) Understand how social environment interacts with endocrine physiology to produce behavioral complexity; 3) Determine lasting effects of early developmental differences on adult traits including survival and reproductive success; 4) Broaden our phylogenetic perspective of developmental psychobiology by studying other taxa, including an endangered parrot species that ranges freely on the Brownsville campus and elsewhere in the Rio Grande Valley.

Recent Publications

R. Eggleston, N. Viloria, S. Delgado, A. Mata, H. Y. Guerrero, R.J. Kline, S. R. Beissinger & Berg, K. S. (2022). Vocal babbling in a wild parrot shows life history and endocrine affinities with human infants. Proceedings of the Royal Society B, 289(1976), 20220592. https://doi.org/10.1098/rspb.2022.0592

C. M. M. Arellano, N. Viloria, S. Delgado, & K. S. Berg, K. S. (2022). Allo-preening is linked to vocal signature development in a wild parrot. Behavioral Ecology, 33(1), 202-212. https://doi.org/10.1093/beheco/arab126

K. S. Berg, S. Delgado, A. Mata-Betancourt, J. S. Krause, J. C. Wingfield, S. R. Beissinger, Ontogeny of the adrenocortical response in an extremely altricial bird. Journal of Experimental Zoology Part A: Ecological and Integrative Physiology. 331:521-529 (2019). https://doi.org/10.1002/jez.2317

K. S. Berg, S. Delgado, A. Mata-Betancourt, Phylogenetic and kinematic constraints on avian flight signals. Proceedings of the Royal Society B. 286, 20191083 (2019). https://doi.org/10.1098/rspb.2019.1083V.

Radchuk, et al., Adaptive responses of animals to climate change are most likely insufficient. Nature communications. 10, 1–14 (2019). https://doi.org/10.1038/s41467-019-10924-4

I. Berkunsky, et al., Current threats faced by Neotropical parrot populations. Biological Conservation. 214, 278–287 (2017). https://doi.org/10.1016/j.biocon.2017.08.016

K. S. Berg, S. R. Beissinger, J. W. Bradbury, Factors shaping the ontogeny of vocal signals in a wild parrot. Journal of Experimental Biology. 216, 338–345 (2013). https://doi.org/10.1242/jeb.073502

K. S. Berg, S. Delgado, K. A. Cortopassi, S. R. Beissinger, J. W. Bradbury, Vertical transmission of learned signatures in a wild parrot. Proceedings of the Royal Society B: Biological Sciences. 279, 585–591 (2011). https://doi.org/10.1098/rspb.2011.0932

K. S. Berg, S. Delgado, R. Okawa, S. R. Beissinger, J. W. Bradbury, Contact calls are used for individual mate recognition in free-ranging green-rumped parrotlets, Forpus passerinus. Animal Behaviour. 81, 241–248 (2011). https://doi.org/10.1016/j.anbehav.2010.10.012

K. S. Berg, R. T. Brumfield, V. Apanius, Phylogenetic and ecological determinants of the neotropical dawn chorus. Proceedings of the Royal Society B: Biological Sciences. 273, 999–1005 (2006) https://doi.org/10.1098/rspb.2005.3410