Jeffrey Lucas
Professor of Biological Sciences (dynamic optimality models in behavioral ecology; avian communication)
Our lab primarily studies animal communication, both from the
perspective of the receiver and from the perspective of the sender of signals. We have been running auditory tests on a broad range of species to test whether habitat constraints on the propagation of vocal signals is reflected in the hearing capabilities of birds found in a variety of habitats. Birds at the Ross Reserve, for example, appear to specialize on frequency resolution at the cost of poor resolution of rapid spectral changes in songs. Birds in open habitats show the opposite patterns. We have also been interested in seasonal plasticity
of the auditory system, primarily as it relates to season-specific use of vocal signals.
We have also been studying the chick-a-dee 'language' of Carolina chickadees. This is one of a very few syntactically complex call systems in birds. We are trying to understand what these syntax properties actually are and the range of information that is encoded in the calls.
Two recent papers from the Lucas lab address two aspects of animal communication. With Eric Bestrom, an undergraduate biology student, they showed that propagation properties of the brown-headed cowbird song are habitat dependent. While this statement is not surprising, the surprising aspect of the study was that cowbird song propagates further in open urban habitats than in either open grassland habitats or in wooded habitats. This is important because cowbirds are nest parasites that lay eggs in a wide range of host species. Males that can project their songs over longer distances presumably will be better able to attract females and ward off competing males. In a second paper, they showed that the hearing capacity of house sparrows changes drastically from winter to spring – but the change is only seen in females, not in males. Indeed, the changes in the auditory system of females match differences typically seen between species! This result is important because it suggests that reproductive hormones not only prime females for reproduction, but they also retune their auditory system to allow them to extract relevant information from song when they are about to breed. Moreover, the lack of seasonal change in males suggests that males do not process the details of their song (given when males fight each other) the same way that females process the song.
Visit Jeffrey Lucas' homepage for more detailed information about his research.