How Do Birds Fuel Up for Migration?

Today we’re hearing from Bret Serbin, the Outreach Coordinator for the Long Island Field Office, as she shares how birds prep for long-distance migrations.

As children migrate back into classrooms, their feathered friends are migrating south for the winter.

Geese are among some 350 species of North American birds that migrate long distances for the winter months. Photo by Pixabay

The arrival of fall signals the departure of many migratory birds. Every year, approximately 350 species of North American birds participate in long-distance migration. Many cover thousands of miles to reach their wintering grounds in Central and South America.

Birds as tiny as the piping plover engage in this great migration. The typical adult piping plover weighs less than 2 ounces! Yet these petite plovers travel from their breeding grounds on such Northern shores as Long Island and the Great Lakes to winter in tropical destinations like the Bahamas and Cuba.

A tiny piping plover chick that will need plenty of nutrients to prepare to fly south. Photo by Victoria Lima/ USFWS

So how do these tiny birds fuel up for their long flights?

The key to their endurance lies in wrack, the green seaweed mixture found along the high tide line on most beaches. These giant green clumps or dried plant material may seem unappealing to humans, but for many migratory shorebirds, wrack’s a snack!

 

An example of beach wrack. An abundance like this can feed lots of birds and other beach creatures!

Wrack is mostly composed of sea grass that comes loose and washes ashore with the tide. Along the way, it can collect a variety of other substances. Once ashore, this rich organic mixture becomes a habitat for a number of creatures, including plants and insects. In fact, about 40 percent of invertebrate species that live on beaches depend upon wrack.

These invertebrates serve as one of the primary food sources for birds like the piping plover. The accumulation of wrack is crucial in providing this food source since the unstable conditions of the sand and the waves make it nearly impossible for plants to grow or insects to live along the shoreline.

Those big piles may not look like much to the average beachgoer, but they provide a beachy buffet for birds en route to their winter homes.

If you’re looking to help send the birds off on a successful journey, working to maintain this important food source is a great way to start. Beach grooming and driving pose serious threats to wrack, as these activities can remove wrack from its natural place on the shore or crush this delicate ecosystem and all the organisms it hosts.

Beach raking like this deprives shorebirds of a crucial source of nutrients. Photo by Wikimedia Commons

If you live in a beach community, encourage your neighbors and beach managers to minimize beach raking in order to protect this important resource. And no matter if you’re a beach bum or a landlocked bird lover, you can help educate others about the importance of this material so that the birds can snack on wrack wherever they go.

The birds’ seasonal departure reminds us to help ensure their safe return year after year. The piping plover, for instance, has experienced such population decline as to be listed as federally endangered in the Great Lakes and threatened on the Atlantic Coast and in the Northern Great Plains.

Given its low numbers, a piping plover in flight is a very welcome sight! Photo by Steven Tucker/USFWS

With this in mind, it’s important to help the birds get fortified for their long journeys so that they can return to us in the spring.

Weathering the storm: piping plovers flock to Long Island beaches

If you live in the Northeast, you won’t soon forget 2012’s Hurricane Sandy. But there is one storm story you may have yet to hear.

Along some areas of the Long Island coast, strong winds and waves washed over the beaches, spreading out sand to create the sandy, open spaces that the island’s winged residents rely on for nesting. For biologists, the restored beach habitat was a sign of hope for the threatened piping plover, whose numbers had been precariously low in New York.

An example of an overwash area on Fire Island Wilderness area Photo credit: USFWS

Researchers from Virginia Tech investigated the effects of Sandy on Long Island with the help of the U.S. Fish and Wildlife Service, the National Park Service, New York State Office of Parks, Recreation, and Historic Preservation, Suffolk County, and the U.S. Army Corps of Engineers. In comparing 2010 and 2015 plover habitat areas and population abundances, they found a substantial increase in suitable habitat and a modest population increase. Notably, more than half of the new habitat on Fire Island and Westhampton Island was created during the storm, with the rest of the habitat engineered by the Corps.

Outreach Coordinator Bret Serbin with Long Island Field Office biologists at the Fire Island Wilderness area. From left: Steve Papa, Kerri Dikun, Bret Serbin, and Steve Sinkevich. Photo credit: USFWS

This increase in available habitat likely contributed to the 40.6 percent increase in plover population on Fire Island and Westhampton Island since the hurricane. This boost is a welcome addition for the bird, which faces numerous threats and is struggling to reach the goal of 575 pairs set out in the federal recovery plan. The researchers also found that the number of nesting pairs in the area has increased over the past 5 years, and they are optimistic that 2018 will be a year of continued productivity for the birds in the area.

Since piping plover chicks have to forage for themselves, plovers like to build nests on flat open beaches close to the shoreline where they have easy access to the tiny invertebrates that they feed on. By creating a number of new overwashes and breaches, Sandy helped expand the territory where plovers and their chicks can live, eat, and grow before their winter journey.

A rare sight: an abundance of piping plovers! Photo credit: USFWS

The reaction from the local plover population has been telling: among new and returning plovers at each beach in the study area, more than 80 percent chose the newly-created habitats to build their nests. And the new plovers exclusively nested in these new areas, completely avoiding the less favorable habitat that existed before Sandy’s contributions. The Hurricane Sandy beach redesign seems popular among the plovers.

This new habitat inches the birds one step closer towards recovery. But what the researchers call a “modest increase” in population is still a long way off from the desired plover population on Long Island. And since much of the newly created habitat is not in protected areas, only time will tell how long and how much the birds will really be able to enjoy these new spaces. To recover this species and others that depend on storm-generated habitat, we must look for solutions that balance shorebird habitat creation while protecting human infrastructure so that we can both weather the storm.