Flight Feathers

When we arrived on the Yukon River Delta in mid-May, some of the shorebirds were just arriving too.  We would find areas on our survey plots that had small flocks of feeding shorebirds instead of one or two defending pairs.  We saw flocks of Pectoral Sandpipers, Long-billed Dowitchers, and Red-necked Phalarope at particularly good feeding sites.  Many of these birds would be moving on to other Alaskan breeding sites, like the Arctic National Wildlife Refuge, or Seward Peninsula, while others seemed to be establishing themselves as residents, and were testing vocal capacity and partial flight displays as growing signs of territorial aggression.

 

A Red-necked Phalarope male makes a delicate fluttering but failing attempt to copulate with a very grumpy mate.  These diminutive shorebirds spend the majority of the year out in the Pacific Ocean, floating on the high seas eating tiny marine life brought to the surface in upwelling currents.

A Red-necked Phalarope male makes a delicate fluttering but failing attempt to copulate with a very grumpy mate. These diminutive shorebirds spend the majority of the year out in the Pacific Ocean, floating on the high seas eating tiny marine life brought to the surface in upwelling currents.

 

These new arrivals had come from winter sites on both sides of the Pacific, the western Atlantic, Caribbean, and throughout the Gulf of Mexico.  As an example, Red-necked Phalarope likely spent the winter at sea in tropical ocean waters off of the Pacific coast of South America.  As the days have passed, we have the sense that migrants have moved on and the residents are now getting down to business.

 

This male Pectoral Sandpiper, newly arrived in crisp plumage from the grasslands of Argentina, is making himself visible by perching above the grass on a piece of driftwood. His black chest feathers are covering a large air sac he inflates to make one of the most distinct sounds on the tundra, the wooooom wooooom woooooom booming of his courtship flight.

This male Pectoral Sandpiper, newly arrived in crisp plumage from the grasslands of Argentina, is making himself visible by perching above the grass on a piece of driftwood. His black chest feathers are covering a large air sac he inflates to make one of the most distinct sounds on the tundra, the “wooooom wooooom woooooom” booming of his courtship flight.

 

The shorebirds we are counting are no longer using their wings to propel them on hemispheric journeys, but are using them to secure a territory, a mate, and to produce a four-egg nest.  The strong outer flight feathers on their wings that cut through the air on night-and-day flights, flapping millions of strokes during migration to get them here, now come into play during a very intense period of courtship, territorial battles, defense, and fleeing.  This is the period of great activity. The shorebirds are in motion in somewhat of a tundra dance—all in the very serious game of reproduction.  This is the brief period when we, as observers, can try to understand how many of each species we have on our randomly selected 40 acre plots.  Once the birds have a full clutch of eggs, the tundra starts to get quiet again, as incubation begins and embryos develop.

 

The buzzy flight display of a Semipalmated Sandpiper establishing his area of grass and wetland on the Yukon Delta National Wildlife Refuge. Primary flight feathers seem to glow in the morning sun.

The buzzy flight display of a Semipalmated Sandpiper establishing his area of grass and wetland on the Yukon Delta National Wildlife Refuge. Primary flight feathers seem to glow in the morning sun.

 

Ironically, the outermost ten feathers known as “primary flight” feathers that are so important during migration and now the breeding season, were grown on migration stopover periods the preceding year.  The nutrients of these feathers came from foods that these birds ate on the mudflats thousands of miles from the breeding grounds.  To grow these strong feathers takes a tremendous amount of food, usually in the form of invertebrate animals, pulled from soft mud or intertidal sands of a low tide beach.

 

Bar-tailed Godwit males, locked in a territorial chase on wings built for speed, have come from as far away as New Zealand and Australia.  The outer ten “flight” feathers are well defined on the birds in this photograph. Bob Gill, a member of our survey team, was instrumental in discovering that Bar-tails leave Alaska in late summer after breeding and what seems like an impossibility, fly non-stop for nine days to New Zealand.  Bob observed a bird last week on the Yukon Delta that had been banded in Queensland.

Bar-tailed Godwit males, locked in a territorial chase on wings built for speed, have come from as far away as New Zealand and Australia. The outer ten “flight” feathers are well defined on the birds in this photograph. Bob Gill, a member of our survey team, was instrumental in discovering that Bar-tails leave Alaska in late summer after breeding and what seems like an impossibility, fly non-stop for nine days to New Zealand. Bob observed a bird last week on the Yukon Delta that had been banded in Queensland.

 

The fact that the flight capability of these shorebirds is dependent upon finding available, reliable, high quality and abundant food sources in distant places emphasizes the need for cooperative international conservation efforts.  The Yukon Delta shorebirds are carrying proteins in their feathers from coastal beaches, freshwater wetlands, and interior grasslands in places as diverse and distant as South Carolina, Hawaii, Australia, China, Ecuador, Brazil, and Argentina.

 

These Long-billed Dowitchers will soon be on eggs, their ornate plumage blending with grass to make them almost completely invisible to predators.  This pair could have spent the winter in the coastal lagoons of Texas or Louisiana.

These Long-billed Dowitchers will soon be on eggs, their ornate plumage blending with grass to make them almost completely invisible to predators. This pair could have spent the winter in the coastal lagoons of Texas or Louisiana.

 

These wing feathers, grown from nutrients in distant wetlands, have not only transported the shorebird thousands of miles and been critical in securing a nesting site and territory, but they will also aid in incubating the eggs and forming a hard outer surface to protect the soft downy feathering under the incubating adult birds from rain.  Once the eggs hatch, the young chicks rely on the adults for periodic warmth as they begin to forage on the abundant insects hatching from the tundra pools.  The adult’s wing feathers act as shelter and containment for the chicks as they regain lost heat and ready themselves for another bout of insect hunting.

 

The hardy Rock Sandpiper is one of the shorebirds on our plots with the shortest migrations, spending the winter on the southern coast of Alaska down through the Canadian coast to Washington and Oregon. These tough little birds frequently flash the white underside of their wings to announce themselves to neighbors and potential mates.

The hardy Rock Sandpiper is one of the shorebirds on our plots with the shortest migrations, spending the winter on the southern coast of Alaska down through the Canadian coast to Washington and Oregon. These tough little birds frequently flash the white underside of their wings to announce themselves to neighbors and potential mates.

 

Almost constantly in motion and exposed to strong sunlight radiation during this period of intense activity, flight feathers will wear down during the breeding season, becoming visibly frayed and pale in color as the weeks go by.  When the shorebirds depart again in late July and August to begin their southbound journey, the feather cycle will begin again at strategic staging sites where the birds will seek and find the nutrients they need to molt the old, and grow new flight feathers that will last a year.

 

A male Whimbrel, still fat from pre-migration feasting, patrols his prime territory near St. Mary’s on the Yukon River.

A male Whimbrel, still fat from pre-migration feasting, patrols his prime territory near St. Mary’s on the Yukon River.

 

Our survey team is privileged to witness this shorebird scene on the immense wetlands of the Yukon, one of North America’s largest rivers, and the complex delta system between the Yukon and Kuskokwim rivers.  We will continue to work at full capacity to ensure the conservation mechanisms are in place to provide the habitats these birds need throughout their migration cycles.

One thought on “Flight Feathers

  1. “The Yukon Delta shorebirds are carrying proteins in their feathers from coastal beaches, freshwater wetlands, and interior grasslands in places as diverse and distant as South Carolina, Hawaii, Australia, China, Ecuador, Brazil, and Argentina.”

    Wow! What an impressive expression of why we need to preserve habitat in all places. Thank-you so much for this.

    One of my great joys of following the journal(s) of the Manomet research teams is getting to view Brad Winn’s photographs!

    Warmly, June

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