Analysis of the Social / Alarm Call of the Red Siskin

The Venezuelan black-hooded red siskin (Carduelis cucullata) is an endangered species of finch from South America. Efforts currently are underway in the United States to help this species increase in number through a captive-breeding program. Studies to analyze possible differences in siskin vocal communication and their potential consequences will help identify obstacles to overcome in both captive breeding and reintroduction efforts. Vocalizations of captive-bred red siskins held at the Milwaukee County Zoo, a private facility in Mendota, Illinois, and the University of Wisconsin-Stevens Point were recorded during the siskin breeding seasons of 1992 and 1993. Social / alarm calls of 15 red siskins ( 5 males and 10 females) were documented and described and then edited and analyzed. All recordings were analyzed using the Macintosh computer program Canary 1.1™; and 4 frequency and temporal measurements from 564 call sonagrams were measured and compared to determine statistically significant differences within and between individuals. Although call variation between individuals, sexes and flocks was difficult to discern aurally, descriptive and statistical analyses revealed significant differences in some features within and between these groups. Data from this study revealed that some captive-bred red siskins can be identified individually by their social / alarm call sonagrams, and qualitative analyses of sonagrams accurately identified 47% of the birds recorded. Inter-individual variation was greater than intra-individual variation (P<0.001) for all 4 parameters. Females had a significantly greater change in frequency than males (P=0.013). Significant differences for mean frequency (P=0.016) existed between 2 of the 3 flocks. There were significant differences in all 4 parameters for one male bird while at 2 different locations (P