“Fall migration” forecast and analysis begins

Andrew Farnsworth The Cornell Lab Aug 08, 2014

Although many species in the US and Canada have been on the move for the past month or more, BirdCast begins its seasonal regional migration forecast and analysis series. Please check visit us frequently to see updated weekly posts about species on the move in your area! The animation below shows the past week in daily snapshots of nocturnal migration on weather surveillance radar over the continental US.

Much of what we see in this animation describes a typical summer pattern on radar. We have scattered showers in portions of the West (e.g. monsoon type rains in the Desert Southwest) and Northeast, and we have some some strong storms in the Great Plains and in portions of the Gulf Coast and Southeast. These are the blocky and irregular patterns that contrast with the much more uniform stippled patterns of birds, insects, and bats. These biological targets, so to speak, are also clearly apparent over many areas of the continent, particularly in the Plains and Texas last weekend and expanding to the east over the course of the rest of the week. Although migrant birds were on the move, with insects and bats, in the nightly snapshots of this past week’s animation, moderate bird migration was likely responsible for a substantial portion of the 1-5 August patterns in the central and southeastern portions of the continent, and light migration in the northeastern portions of the continent for some of the patterns on 6 August. Species on the move included Semipalmated Plover (Great Plains), Black-bellied Plover (Upper Midwest and Northeast and Gulf Coast and Southeast), Lesser Yellowlegs (Great Plains), Ruddy Turnstone (Gulf Coast and Southeast), Baird’s Sandpiper (Gulf Coast and Southeast), Yellow-billed Cuckoo (Great Plains), Blue-winged Warbler (Upper Midwest and Northeast), Black-and-white Warbler (Upper Midwest and Northeast), American Redstart (Upper Midwest and Northeast), Yellow Warbler (Gulf Coast and Southeast), Wilson’s Warbler (West), Lazuli Bunting (West), and Baltimore Oriole (Upper Midwest and Northeast).