Another highlight was the gigantic offshore flock of Long-tailed Ducks at Grand Haven Pier totalling conservatively 3,500 individuals, likely many thousands more. The flock was circulating north to south in the air, landing on the water, foraging and drifting north, then flying south again. In a single swipe I estimated 2,500 flying birds, but most were on the water during this time, and I could not count them. The birds were about 1-1.5 miles offshore, and at some point someone needs to get a boat or aircraft out there to get a good handle on this amazing phenomenon. Here is a digiscoped video of these birds:
It appears that there are very few data on these large flocks in Lake Michigan, except for shoreline counts by birders which occasionally document up to 20,000 to 30,000 individuals. It seems we have no idea what the total number of birds using the lake is, nor how far out into the lake they go. This is especially important because wind power in the middle of the lake is already being proposed, and it will be vital to figure out its possible effects on birds such as LTDUs as soon as possible.
