Ginger: Thanks for posting that incredible shot from Flyway chat. I actually saw that behavior in person last year, came home and looked up what was happening on the Cornell site. Here is their information:
"Formation flocks typically long lines, often with apex forming Vee or Jay (unequal length of arms), also in irregular patterns. Birds in line sometimes rise and fall in succession creating a wave-like effect. Alternate flapping (60%-75%) and gliding flight, usually at moderate height of 12-15 m (Behle 1958), at about 50 km/h (Ross 1933 in Behle 1958). Lead bird usually (42 of 58 instances) initiates phase shift between flapping and gliding, then phase shift passes back through flock in a wave. Response time usually < 0.5 s between successive birds. Wingbeat frequency stable at about 160-175 beats/min. Percent time flapping and wingbeats/hour tend to decrease behind leader, suggesting energy saving when in formation."
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Topic: Flyway Cam NFWR La Crosse (Read 410705 times)