Hundreds of Long-tailed Ducks and Greater Scaup, interspersed with
White-winged Scoters, a few Lesser Scaup and one Black Scoter, were
diving in synchrony (unison) in the channel at the bridge in Tommy
Thompson Park in Toronto on 15 December 2019.
The behaviour of the diving ducks was predictable. They dove in
unison, stayed under for about 40-60 seconds, came to the surface,
rested, then dove again. With each successive dive they arrived at
the bridge, then they flew back several hundred metres and started
diving again in the direction of the bridge. Tommy Thompson Park in
Toronto on 15 December 2019.