A Stochastic Analysis of the Display Behavior of the Red-Breasted Merganser (Mergus Serrator)

Abstract

Abstract 1. We have used the methods of stochastic analysis to investigate the timing of two actions - the Head-flick and the Salute-curtsy - in the display of the Red-breasted merganser duck. 2. The intervals between Head-flicks by individual birds cannot be distinguished from a random, exponential time series, in which the occurrence of each event is independent of preceding events. 3. The intervals between Salute-curtsies are unlikely to be distributed exponentially. There is a deficit of short intervals and an excess of intervals between events of about 250 frames durtion. The Salute-curtsies do not occur independently of one another. 4. Variance-time curves and power spectra show that there is a marked periodic component in the timing of Salute-curtsies, but periodicity is not detectable in the performance of Head-flicks. 5. Cross-correlations analysis shows that there is a strong interaction between the occurrence of Salute-curtsies by the different birds in the group and between the performance of Head-flicks and Salute-curtsies. There is no detectable relation between the performance of Head-flicks. 6. We conclude that there is a strong tendency for birds to perform series of two or three Salute-curtsies with an interval of about 250 frames between each action. There is also a strong interaction between the performance of Salute-curtsies by the different birds. There is some tendency for Head-flicks to occur at greater than chance frequency during a period just before the performance of a Salute-curtsy. The remainder of the Head-flicks appear to be distributed randomly.