Fall mallard migration is well underway, with many birds making significant movements during the early-November cold spell. As temperatures have since moderated across much of the flyway, most individuals appear to be holding steady in regional stopover or staging areas. Each path represents an individual mallard equipped with a GPS transmitter. Most of these birds were originally marked last November, though several are now completing their second or even third fall migration since tagging—prov

The Basics of Bird Migration: How, Why, and Where