Fueling Up: Visiting Migrant Birds Will Soon Fly Non-Stop from Cape Cod to South America
July flew by and so now are migrant birds in larger numbers. With August upon us, bird migration has begun in earnest for many species, especially Arctic nesting shorebirds. These long distance travelers are literally the wind birds as they cruise from the High Arctic in the northern reaches of land on the planet to the southern end of the continents in the Southern Hemisphere. They keep to a travel schedule that we really cannot imagine.
With the increasing use of changing technologies, many species of birds are being fitted with satellite transmitters and geotags that allow for more and better data on where these birds go, how fast they go, where they stop, and the data is shedding so much light on things we thought we knew that it really is amazing. The feats of migration, the stopover points, and the nonstop flights over thousands of miles of open ocean, seems the stuff of science fiction - but this is real.
Birds that are visiting the Cape and Islands now, like Whimbrel and Hudsonian Godwits, 2 species of large shorebirds, make outrageous non-stop flights over many thousands of miles long. They depart from the Outer Cape and don’t stop until they hit the northern reaches of South America. They are feeding like crazy at favored locations now, doubling their body weight, storing subcutaneously the fat that they are then able to use just like an internal combustion engine uses gasoline, to make these incredible migratory flights. The byproducts of burning this fuel are heat generated by their large pectoral muscles that can be as much as half the birds weight and water that they respirate out.
Things are starting to change dramatically in the natural world, the bird’s world. With the passage of any cold front with a cool northwest wind there will be lots of “chip” notes emanating from the sky. Not only are shorebirds on the move but landbirds such as Great Crested Flycatchers, Yellow Warblers, American Redstarts and Northern Waterthrushes are also on the move. Yellow Warblers are moving in numbers and many have been recently seen at any of the coastal funneling points where people were on hand to see them including Gooseberry Neck in Westport, Cuttyhunk Island, the Gay Head Cliffs in Aquinnah, Woods Hole in Falmouth, Jackson Point on Nantucket and Morris Island in Chatham. These aforementioned locations are all excellent fall birding locations and on mornings after big nocturnal migrations they can be rocking and rolling with large numbers of migrant birds.
So what is important to realize is that even though it is only the start of August, mid-summer if you will for the human population on the Cape and Islands, it is fall for the bird life and many species are passing by, some staying as much as 3 weeks before continuing their southbound journey.
The regions beaches, tidal flats and sandbars are alive with gulls, myriad species of terns, staggering numbers of waders in the form of plovers and sandpipers, and lots of herons and egrets. The nearshore and offshore waters are thriving with bait fish that attract seabirds and whales. The woods and fields are busy with birds either preparing to head south by growing new feathers and storing fat or getting ready to attempt to survive the upcoming winter. Regardless of what they are preparing to do they are preparing for what’s ahead as their survival depends upon it.