Niwot migrations: Birds of a feather fly great distances together

Hundreds of Canada geese take off from the mowed fields around Dodd Reservoir where they have spent the day browsing for food. The evening sky is going purple after a clear day. Some of these geese make a fuss, honking as they take off. Others silently glide away, the turmoil of a disordered flock resolving into a giant V-formation that disappears into the distance. But where are they going?

Accor...