Douglas A. Nelson - US grants

9513821 Nelson Vocal learning in song birds is a complex motor skill in which young males memorize the songs of adults, and then use their memory to control their own song output. One consequence of vocal learning in birds is the formation of vocal dialects in which males at one locality sing similar songs that differ from those of males at other localities. Until recently, it has been assumed that a single process is involved in the formation of dialects: the young bird imitates one or more adults at the time and place the youngster settles upon a breeding territory. Recent evidence suggests that an independent process of selective attrition of songs from a large repertoire acquired in whole or in part at a different time and place can also lead to song sharing between neighbors. The proposed research will examine the role of song overproduction and selective attrition in the formation of local song dialects. The PI will take a comparative approach by studying different subspecies of the white-crowned sparrow (Zonotrichia leucophrys). Field observations, and laboratory and field experiments will be conducted to compare processess of vocal development in one subspecies that does form local dialects (Z. l. oriantha or Z. l. leucophrys) with another that does not (Z. l. gambelii). In the field, the PI will observe vocal interactions between males as they settle upon territories, and determine the sizes of their song production repertoire early in Spring, and compare whether they selectively retain or reject songs that match their neighbors. This will test the hypothesis that developmental pathways are conserved during evolutionary diversification, and that changes often are made to terminal stages. The PI will then conduct field and laboratory playback tests contrasting the song matching behavior of males of two subspecies. These experiments are designed to reveal differences in the perceptural categorization of songs, and to identify possible genetically-based differences in song pe rception. The PI will also employ a new method for measuring song learning that is independent of the production of imitations to examine how songs are memorized during the sensitive phase and during the subsequent storage interval. Finally, the PI will conduct a song learning experiment to assess whether live tutors modiy or extend the early sensitive phase for song acquisition, as compared with tape tutoring.

Animal Behavior Program
Nontechnical Abstract


Proposal #: 9816651
PI: Nelson, Douglas A.
Title: Coevolution of Genes and Animal Cultures



This project will examine the idea that a culturally transmitted trait, bird song, influences the genetic structure of animal populations. Song birds learn their songs in the first few months of life by imitating the songs of adult birds. Song learning often leads to the formation of regional dialects, much as in human speech, which is also learned early in life. It has been suggested that if both males and females learn their songs and then chose mates based on song, then gene flow between dialects will be restricted. Nelson and Parker will study the song dialects of the Puget Sound white-crowned sparrow along
The northwest coast of North America. A series of song playback experiments will be used to define dialect boundaries that are perceptually meaningful to the birds. The researchers will then compare genetic variation between dialects using genetic markers produced from tiny blood samples taken from birds. The genotypic data will also be used to follow dispersal of birds relative to dialect boundaries.

Since song dialects are one of the few examples of long-lasting culturally-transmitted traditions known in animals, they provide a useful model system for study of the vocal learning process, and how learned vocalizations (culture) may affect the genetic structure of animal populations. This project will provide basic information on these issues, which may ultimately prove useful in understanding similar processes in humans.

Summary: The PIs propose to study insect respiration using the synchrotron X-ray imaging facility at Argonne National Laboratory. In previous studies, the PIs used this approach to show that tracheae in the head and thorax rapidly contract and expand in diameter, causing a change in tracheal volume that appears to aid respiration. The PIs plan to extend these observations by determining the muscle/skeletal mechanisms involved in these changes. The PI will also determine how broadly the mechanism of tracheal compression occurs in the various insect orders. In a second study, the PIs will investigate the role of tracheal compression in respiration by correlating the release of CO2 with cycles of tracheal compression. These studies will be done on several species. The PIs also plan to study individuals of different sizes from the same species to see how growth affects this process. Finally, the PIs will analyze the role(s) of insect mouthparts in breathing to determine the coordination of respiration with motions of the mouthparts during feeding.

An award to the Borror Laboratory of Bioacoustics at The Ohio State University and the Florida Museum of Natural History (FLMNH) will fund the conversion of animal sound recordings in the latter institution's collection to digital format. These recordings are currently housed on analog magnetic tape, which has a finite lifespan, and degrades in quality with each use. Conversion to digital format will ensure the preservation of this important collection, and make it much easier for FLMNH staff to serve clients in the future.

Collections of recorded animal sounds provide an important resource for scientists interested in the behavior and evolution of animals, for members of the public interested in natural history, and for various commercial enterprises. The FLMNH collection of animal sounds is one of the three largest in North America, and is very strong in birds from the New World tropics, a center of avian biodiversity. In digital format, users will be able to search the collection database and audition every recording in mp3 format. The collection database will also be linked to ORNIS, an NSF-funded consortium of ornithological collections. Finally, collections of bird sounds will be reissued in mp3 and CD format for use by birders and by biologists conducting population surveys.