International Journal of Comparative Psychology

Wild

zebra finches use distance calls in a wide variety of contexts including flight, mild alarm, perching, and courtship. The call is also thought to allow paired males and females to maintain contact in large flocks. The purpose of this study is to compare the acoustic structure of distance calls of wild and domesticated zebra finches. We analyzed distance calls from our own colony and combined the results of this analysis with the findings from two other published studies on distance calls of domesticated finches. The results from these studies were compared to earlier research on the distance calls of wild zebra finches. Overall, domesticated male and female zebra finches produce calls that have longer duration, lower fundamental frequency, and higher frequency of maximum amplitude than those of wild zebra finches. These differences were generally consistent across different domesticated populations. Domesticated males produce distance calls in which the frequency modulation of the noise element is substantially different from the noise element of wild males. Furthermore, there was little consistency in the structure and location of the male's noise element across different domesficated populations. It remains to be demonstrated whether these changes have altered the function of this call in domesticated finches.  

This paper

is a response to Campbell and Hodos' continuing critiques of the field of comparative psychology. Their opinion to the contrary, I show that anagenesis is still a useful concept to evolution scientists and that anagenetic analysis provides a viable and fruitful approach to theory development in comparative psychology. Anagenesis suggests improvement with evolution and the idea of complexity as an indicator of evolutionary progress is discussed. Finally, the paper discusses the utility of a modified form of the Scala naturae, namely the concept of integrative levels by showing how T. C. Schneirla has used this idea as the foundation of his significant theoretical contributions to comparative psychology