Wingbeats in the Night
Last night, October 8th, 1.25 billion songbirds migrated across the Untied States; a hugely spectacular number. A normal big migration flight in the Fall is 700 to 800 million birds. In Vermont, 17,742,700 crossed the state last night of which 6,747,600 crossed Rutland County where I live. These are all very, very high numbers that are beyond our comprehension. The songbirds were flying at an elevation of around 2000’ and going about 38 mph. the propulsive factor was a north wind, a tailwind, coming after several nights of south winds, headwinds. Birds don’t migrate into headwinds.
These numbers are not numbers I conjured out of the dark night air. They are numbers produced by computers counting birds recorded on Doppler radar. There are 159 Doppler radar stations scattered across the contiguous US, one of which is in Burlington, Vermont. Every night during the migration season- March-May & August-November- migrating songbirds are recorded by these radar stations and tabulated by Cornell University. Nightly results can be seen on Cornell’s eBird Migration Dashboard app.
!7 million is a huge number single night for Vermont but is nothing compared to the numbers for both Georgia and Mississippi on the 8th. Both of these states were crossed by over 100 million birds on that night. 100 million birds! That works out to 10 million birds an hour (a ten-hour flight) or 166,666 birds a minute. And no you can’t imagine. The flight was entirely in the dark and entirely too high to hear; it was an invisible passage, silent travelers heading across dark waters to the shores of Mexico.