Birders Anticipate Possible Influx of Unusual Storm-flung Birds
With a few days of stormy weather ahead of us, it’s time to talk about birds and hurricanes. Here in the northeast, hurricanes originating in the Caribbean typically weaken into tropical storm before we see them, sparing us most of the destruction, and setting up potentially exciting times for birders on the Cape.
Strong hurricanes barreling up from the south are famous for bringing tropical seabirds well north of their normal range, often depositing them well inland. Hurricane Irene in August of 2011 brought Sooty Terns and White-tailed Tropicbirds as far inland as the Berkshires, where they must have felt a long way from their Caribbean homes.
But the larger continental weather patterns around hurricanes can be complex, meaning you never know what they may bring you. During Hurricane Sandy back in 2012, some of the more expected storm-blown Caribbean waifs turned up in Massachusetts, like Bridled Terns and Brown Pelicans. But an unusual and simultaneous weather pattern known as a Rex Blockage set the scene for an unprecedented invasion of a European species of shorebird known as the Northern Lapwing.
While Rex Blockage sounds like what happens when your dog eats too much cheese, it’s actually a large scale weather pattern that in this case created an east to west flow across the North Atlantic, catching several Northern Lapwings, probably as they were flying from Scandinavia south to Europe and Africa, and brought them across the pond to the eastern United States. I found what I thought was the first one for the state at First Encounter Beach in Eastham that November 1, but it turned out our friend Vern Laux had outdone me with TWO on Nantucket, just 20 minutes earlier.
Birders, of course, love the chance to find super rare, storm-displaced birds during and after a hurricane, but how do the birds themselves fare when the storm hits hard? Like us, most birds, hunker down in a storm and try to stay out of the wind. Satellite tracking data has shown that more mobile species like seabirds will just head out to sea away from the storm until it passes. For migrating birds that end up out over the Atlantic, hurricanes can be a formidable foe. The peak of hurricane season coincides with peak migration for all kinds of shorebirds and songbirds, many of which travel well offshore for thousands of miles, making it difficult or impossible for them to avoid flying into hurricanes.
In 2005, Hurricane Wilma knocked out my power for a week when I was living in South Florida. In turned out it was even more inconvenient for Chimney Swifts en route from Canada to South America. Caught up in Wilma, hundreds of these tiny birds were brought as far away as Western Europe, where most birders had never seen one before. Many didn’t make it, and researchers estimated the Chimney Swift population in Quebec was down 50% the following year, largely attributed to hurricane mortality. Larger birds like Whimbrels are stronger fliers, and satellite tracking has shown that they can fly right through hurricanes, struggling through the powerful headwinds on the north side of the storms before taking advantage of the tail winds on the other side to fly as fast as 90 miles per hour.
As far as Jose is concerned, the consistent northeast winds predicted for the rest of this week should fill up Cape Cod Bay with ocean birds. During these winds, north facing beaches like Sandy Neck in Barnstable or Chapin Beach in Dennis are worth a check, as hard-to-find ocean birds like jaegers, storm-petrels, and phalaropes could be streaming by on their way back out of the bay. Any coastline or inland reservoir should be checked for displaced Caribbean birds like Sooty and Bridled Terns, pelicans, and tropicbirds.
If you see anything unusual, be sure to report it to me, or more importantly to the eBird website, your local Facebook birding group, or wherever you choose to get the word out about your sightings. And stay tuned to this station later this week, when I hope to have a post-storm check in with the Morning Edition folks if any wacky birds turn up. In the meantime, happy storm birding!