STUDY OF CAPTIVE SONGBIRD MIGRATORY RESTLESSNESS, ZUGUNRUHE, BY DIRECT AND VIDEO ACTIVITY OBSERVATION BEFORE, DURING AND AFTER THE AUTUMNAL MIGRATION PERIOD

Zugunruhe, the German word for migratory restlessness, is partly characterized bymigratory birds’ increased activity prior to and during their migration period, particularly afterdusk. This study examined this agitated behavior by daytime observation and nighttime video,supplemented with weight and overnight food choice data. The working hypothesis was that arange of captive migratory birds’ normal restlessness behavior before, during, and after theAutumnal migration period could be identified to differentiate Zugunruhe from aberrantbehaviors resulting from health or other issues. The study consisted of eight subject migratorysongbirds across six species and two nonmigratory songbirds (used as a comparative baseline),residing in the Smithsonian National Zoo collection.Qualitative analyses confirmed daytime and heightened nighttime activity during themigratory period, and also suggested that gender, species, and the captive subjects’idiosyncrasies may affect their Zugunruhe. Quantitative analysis, utilizing paired t-Tests,scatterplots, bar and software activity graphs were less definitive. Paired t-Tests determined thatthe null hypotheses – that the mean difference between particular variables being tested wasequal to zero – could be rejected for some samples and not others. This may result from thesmall sample size and limited four-month study duration. Weight scatterplots confirmed someZugunruhe patterns. A study over multiple migratory seasons and with larger samples ofcaptive and nonmigratory songbirds, may produce data that could reject more null hypotheses.