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Wing tail flicking, a sharp coordinated movement of wingtips and tail, is a common, yet little understood behavior of American Crows (Corvus brachyrhynchos). It may be an expression of anxiety, a signal to other crows, or both. We recognize three levels of intensity, differentiated by height of wing tip flicks and involvement of tail, and propose that fledgling crows will wing tail flick (WTF) less because they may not recognize danger and thus will be less anxious. If also a signal, adults may wing-tail flick to alert other family members to danger. Here, we analyzed over 14.5 hours of video of nine wild crow families with between two and six members. Four experimental trials were conducted with each family: three baseline trials with food alone, and one trial with both food and a novel stimulus, included to induce anxiety. We recorded the number and intensity of wing tail flicks, the age class of the individual, and the amount of time it was in view using BorisTM software. While the behavior of individuals varied within and between families, adults tended to WTF more than fledglings and at higher rates in novel stimulus relative to baseline trials. This supports the hypothesis that adults are more responsive to danger and that learning about perceived threats may increase WTF rates with age. We also found a weak, positive relationship between WTF rate and family size that suggests that WTFs could be socially contagious, spreading through a group once one individual expresses anxiety.



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The Effects of Age, Anxiety, and Family Size on Wing-Tail Flicking in American Crows