Intense Migration at The Straits

Black kites in flight (photo from Wikimedia Commons)

20 August 2021

Raptor migration is underway in Europe and will follow soon in North America. One of the best autumn hawk watches is in Spain at the Strait of Gibraltar, the water gap between Europe and Africa.

Northern Africa looks tantalizingly close — only 9 miles away — but the Strait is too dangerous to cross when the wind is from the east. Called the Levant, it blows 25-45 miles per hour toward the Atlantic, strongly suppresses vertical air motion, and can create an inversion within a few thousand feet of the surface. The birds would be forced into the water if they made the attempt.

3D map of the Strait of Gibraltar (image from NASA via Wikimedia Commons)

A week ago the Levant blew for at least three days forcing migrating birds to stop on the Spanish side. Black kites (Milvus migrans) were thick on the ground 13-15 August as they waited it out.

When the weather changed, Monday 16 August was a fantastic migration day.

Meanwhile songbird migration is heating up in North America. BirdCast shows that last night over 100 million birds flew over the eastern U.S. Tonight’s forecast for Pittsburgh (night of 20-21 Aug 2021) promises to be especially intense. Go birding on Saturday!

Update on Sat 21 August, 11am: What a bust! The birds must have flown over without landing. Lots of robins and blue jays. And it was hot out there.

Snapshot of BirdCast map, 20 Aug 2021 at 00:25

Check BirdCast for migration status in your area. Click here for the Pittsburgh forecast. And get outdoors!

(photos from Wikimedia Commons, embedded tweets from Inglorious Bustards, screenshot from BirdCast; click on the captions to see the originals)

2 thoughts on “Intense Migration at The Straits

  1. We’re going to Frick in the morning! Where were you having luck with warbs? Do you know where the Canada was seen? Thanks!

    1. We saw the Canadas on Lower Riverview and near the top of Falls Ravine Trail beyond the fenced creek. Today someone reported a Cape May at the meadow.

Leave a Reply

Your email address will not be published.