There and Back Again: A Shorebird's Tale

Warmer weather and longer days. For many of us, spring means lighter jackets, the welcome chance to take a late-afternoon walks, and eager anticipation for summer beach days ahead. For the more than 350 species of migratory birds in the Western hemisphere, it means just one thing: time to go.

Increasing day length cues long-distance migrants to depart wintering grounds in Central and South America, embarking on epic journeys to summer breeding grounds that span continents, cross oceans, and total many thousands of miles. And that’s just a one-way trip.     

One group stands out as the undisputed superstars of the migration world. Shorebirds hold the record for longest nonstop flight (an 11-day, 8,435-mile jaunt from Alaska to Tasmania by a Bar-tailed Godwit) and longest total migration of any animal (a pole-to-pole trek of 25,000 miles annually for the Arctic Tern).  

How do they do it, you might ask?  When it’s time to migrate, several adaptations kick in. They pack on fat to use as fuel, often doubling their bodyweight. They also bulk up the size of their flight muscles, heart, and lungs, while temporarily shrinking other organs, like the stomach.

Just as crucially, migrating shorebirds need something else: ‘stopover sites’, or places along their migratory route where they can stop to rest, feed, and build up the fuel reserves necessary to continue flying. That’s where Parker River National Wildlife Refuge comes into play.  

Parker River NWR was established to provide feeding, resting, and nesting habitat for migratory birds. The refuge protects 4,500 acres within the Great Marsh, a designated Site of Regional Importance of the Western Hemisphere Shorebird Reserve Network. Last year, a survey undertaken in the Great Marsh recorded 9,000 shorebirds of 22 different species.

Many people associate the refuge with its most well-known shorebird visitor, the piping plover. This sandy-colored bird ventures north from its Caribbean winter home to nest on beaches across the North Atlantic each summer. But the refuge is also a critical stopover site for many other shorebird species which breed much farther north in the Canadian Arctic. These birds rely on Parker River’s safe and bountiful habitat to give them refuge along their journey.

Of all the shorebirds who stop over at ParkerRiver, the most abundant is the semipalmated sandpiper. Weighing less than a slice of bread, they migrate thousands of miles between South America and the Arctic tundra. Preliminary studies suggest that in the fall, semipalmated sandpipers stop over at the refuge for 2-3 weeks before undertaking trans-oceanic flights of 2,500 miles to the northern coast of South America.

Without protected stopover sites like ParkerRiver, this millennia-old feat could come to an end, not just for sandpipers, but for hundreds of other species, too. Shorebird populations are declining, and many species have lost over 50% of their population in the last three decades.

The biggest threats these populations face are loss of stopover habitat and human disturbance which cause shorebirds to alter their normal behavior, preventing them from successfully migrating and raising their young. There’s a silver lining though. Part of what makes shorebirds vulnerable - their tendency to concentrate at just a few stopover sites along their route - might be the key to helping them. If we can safeguard these essential sites, shorebirds may have a chance.

We are just one stop on a shorebird’s incredible journey: a link in a chain that spreads across two continents. As local stewards of this important habitat, every one of us can make a difference for shorebirds by respecting closed beaches, taking care to walk around flocks of resting and feeding birds, and choosing to leave dogs at home or bring them to designated dog-friendly beaches.

Author Madelyn Kaplin is a member of Biology and Visitor Services teams at Parker River National Wildlife Refuge; she can be reached at madelyn_kaplin@fws.gov.

ACES Youth Corps members hope that you will appreciate the shorebirds you see and their contribution to the beauty of this area. Please share any reflective thoughts by writing to acesnewburyport@gmail.com.

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