Sunday, March 11, 2012

Winter Shorebirds

For Tuesday's Tweets and World Bird Wednesday, I have decided to talk about a recent shorebird sighting I had and explain a little about the three species we saw.
Here in coastal Virginia, we often have small groups of shorebirds winter.  They will often pick some muddy tidal flats to stay around and probe the mud for small marine invertebrates and wait for their nesting grounds to open up for the season.  Most shorebirds winter further south in the Caribbean or South America. But those that stay in North America for the winter likely get a head start on reaching their nesting grounds in the north of Canada.  Migration is very risky and expensive for birds.  After surviving their first summer, migration is the deadliest thing they do.  So, even though many species migrate over great distances, those individuals who can find food closer to their breeding grounds are more likely to survive and will return to their summer habitat earlier (better nesting sites and territories) and in better health.  It is the lack of food at their breeding location, and not the cold weather, that drives birds to migrate.

Shorebirds at Willis Wharf
As you may know from my Gannet post, I went to the southern Delmarva Peninsula (the Eastern Shore of Virginia) with the Hampton Roads Bird Club a few weeks ago.  One of the stops that we made was at Willis Wharf.  It is about 30 miles north of the southern tip of the peninsula on the Atlantic side.  It is a fishing village on a tidal creek and well protected behind some of the barrier islands along the coast.  When we arrived there were extensive mud flats, even though it wasn't yet low tide.  We saw a few hundred shorebirds out in the flats and once we got our scopes on them, we could identify three main species: Marbled Godwits, Willets and (Short-billed) Dowitchers (you can ignore the Ring-billed Gulls in the picture, I did).  I put the Short-billed in parenthesis because the species was identified by others.  It is very difficult to distinguish between the Short-billed and Long-billed Dowitchers in the field and I'm not confident enough to make the distinction.  And no, the bill length is not diagnostic. Their call is useful though; but we didn't hear any. But wintering very near the coast in brackish mud flats is suggestive of Short-billed over Long-billed.
After we were watching for several minutes, a Peregrine Falcon came swooping by and caused the shorebirds to take flight.  It was quite an amazing sight.  Luckily I had my camera ready and was able to capture some good photographs.
Shorebirds take flight from a Peregrine Falcon

We didn't see the Falcon take any birds and after a few passes it went to perch on a tree at the far side of the marsh.  The birds are able to fly and maneuver in tight formation with others of different species.  The tight grouping of hundreds of birds and their frequent turning back and forth is a defensive mechanism.  It is hard for a predator, like the Peregrine, to pick an individual out and attack them. Even though seeing this was quite exciting, it did cause all of the birds to land quite far away.  But after a few minutes, many of them returned.  I guess the eating was better here.  I was able to capture a great image of them all banking to the side as they returned.  I love how they are almost vertical.

Banking to the left before landing

In the picture to the right, you can see all three species.   I have cropped out a section of the upper left of the previous image to show the three species (see below).  You'll find The Marbled Godwits (marked 'A') has a warm cinnamon color to its feathers, is the largest of the three species.  It is also the only of the three with an obviously two-toned bill: black near the tip becoming pink near the head.  The Dowitchers are the smaller birds in this picture.  There are three seen near the 'B'. They are about half the size of the Godwits, have a white spot in the middle of their backs, somewhat shorter tails and show dark towards the wing tips.  When they are feeding, they have a very characteristic probing motion that is likened to a sewing machine.  A very rapid up-and-down motion.  Much quicker than most other shorebirds and continual.  The third species seen in the picture are Willets.  They actually breed in this area as well.  They are larger than the Dowitchers, but not quite as big as the Marbled Godwits.  There is a good example marked by the 'C'.  Willits are easy to identify in flight as they have a long white 'W' stretching from wingtip to wingtip.  They also have a clear call of "pill-will-willet."  

Close-up showing the Godwits ('A'), Willets ('C') and Dowitchers ('B')

We ended up staying for about an hour as the birds continued feeding pretty close by in the mud flats. And I will close with this final picture from that day that I like. Can you find the Willets?


  1. Those Pregrine Falcons will scatter them every time;) Lovely flight images, really well done!

    1. Thanks. It is good to see the falcons back even if we sometimes have competing interests (they want to eat the birds while I want to get closer).

  2. Very nice captures.

    Regards and best wishes

  3. I have lots of shorebirds close to where I live but none of the ones you mentioned migrate down here to Australia. I would love to see them also. Great photos.

    1. As I would love to see some that you have.

  4. Yes I see the willets! Marvelous post, thanks for sharing this experience!