Influence of the Observer on the Frequency of the ‘Morning‐Dance’ in the Arabian Babbler

Abstract

AbstractThe Arabian babbler, Turdoides squamiceps, displays an unusual behaviour, the ‘morning‐dance’. This article examines the influence of the presence and behaviour of an observer on the dance frequency. The results are the summary of more than 3 yr of study by 12 observers, who performed 1335 observations and witnessed 286 dances that took place among 15 groups of babblers. Different experiments were carried out on 148 additional mornings.Different observers witnessed different dance frequencies. Dance frequency witnessed by an observer decreased with observer's experience. Observers watching groups of babblers on single days witnessed more dances than those who watched the same groups for several consecutive days. Dance frequency was higher on the first day of a series of observations than on the following days in the same series. If a group of babblers remained unobserved for one day, the frequency of dancing increased. An evening observation considerably decreased the frequency of dancing the following morning. Feeding experiments did not elevate dance frequency. Experimental disturbance at the roost before dawn increased dance frequency while permanent disturbance and frightening experiments did not. Change in the observer's presence and behaviour caused the babblers to react by dancing. The hypothesis that the observer's presence and behaviour influences different group members differently, and therefore alters the relationships among them, is offered to explain the results that observers can affect the dance frequency.