Shorebirding on the Delaware Bay and an ID quiz of sorts

By Lukas Musher

On Tuesday I drove down to southern NJ to help David Mizrahi of NJ Audubon with his shorebird project that I worked on last year.  He didn't have me do any banding, bleeding, netting, or flagging.  Instead he had me go onto the beach and re-sight flagged Semipalmated Sandpipers.  The beaches are off limits this time of year due to shorebird migration, so I was very lucky to be able to get up and close with the birds themselves, and to get some phenomenal photographic opportunities.  

As I have talked about in the past, several species of shorebirds stage along Delaware Bay each Spring in coincidence with the spawning of the horseshoe crabs.  The fat-rich horseshoe crab eggs provide an invaluable calorie source for the migrating shorebirds, enabling them to finish their journey north to the breeding grounds in the high arctic.  

Fortescue is often one of the best places on the Delaware Bay shore to see the staging shorebirds, and that's where I was.  Above, you can see a few thousands shorebirds or several species (predominantly Semipalmated Sandpiper, Red Knot, Ruddy Turnstone, Sanderling, and Dunlin) roosting on the beach, and getting ready to begin feeding as the tide goes out.

Ruddy Turnstones are one of my favorite shorebirds, and what they lack in rareness, they make up for with charisma – or as Richard Crossley puts it, they are "the sausage dog of birds."

 Semipalmated Sandpipers greatly outnumber all other species, and yet they are one of the most severely declining shorebirds on Delaware Bay.  Red Knots are more famous, but in fact their numbers may be recovering, perhaps due to a strict moratorium on the harvesting of horseshoe crabs in the bay.  David Mizrahi has been studying this small and plain, albeit fascinating Calidris sandpiper for twenty years.  One of the biggest conservation concerns for this species has always been rampant hunting for food many countries throughout Latin America.

 I spent a lot of time scoping and sorting through the tens of thousands of birds looking for flags.  I found Red Knots from Argentina, Ruddy Turnstones and Sanderlings banded in previous years on Delaware Bay, and Semipalmated Sandpipers banded on the bay and two that were banded in Brazil.  I got tired of scoping, though, and took asylum behind the remnants of a disintegrating wooden fence covered in mold and algal residue.  It provided me with enough cover so that I could sit patiently as the shorebirds walked within ten feet of me allowing for fantastic photo ops.

A group of mostly Dunlin and Red Knot begin to take flight as I am noticed from behind the wooden remains.

A Semi banded on Delaware Bay!

One of several Red Knots I found that were flagged in Argentina!

Another D-bay Semi!

Exhausted by their long flights from South America and in preparation for the long flight to the arctic, Semipalmated Sandpipers recover and feed ferociously on the fatty crab eggs.

Incoming!  The Semipalmated Sandpiper landing on the right was flagged on Delaware bay by David's team.

Dunlin, Semi Sandpipers, and a Red Knot take flight, as the rest of the weary flock, including a couple of Short-billed Dowitchers, anxiously scamper forward.

Perhaps the most charismatic and infamous of North American shorebirds, a Red Knot in flight steals the frame from the other species taken to wing.

I may have spooked these Dunlin and Semis, but they know where they want to feed (AKA where the eggs are) and they come right back in to where they were before after two to three laps around the beach.

Finally, I leave you with a few photos of this bird.  I believe this to be a male Western Sandpiper, and upon consulting an expert, he agreed, though said he could not be 100% certain without photos of the underside.  I can tell you this, though, the bird was stockier and ever so slightly larger than the other Semis, and I remember thinking right away that it could be a Western based on build, rufous tones on the upper parts, and longer breast streaking than the typical Semi.  I welcome other opinions on this bird so feel free to post thoughts in the comments.  If it is a Western Sandpiper, this late date in NJ would make it very, very rare.  I will also be consulting more experts over the next few days, so maybe we can figure something out....most likely there won't be consensus.

Note rufous tones on scapulars, cheek, and cap, relatively long bill (though on the small side for Western, making it a likely male if confirmed), and blocky (not round like Semi) head.  I personally see some streaking making its way down the flanks, which Semi doesn't have.

He looks fat from this angle, more in favor of Western in my opinion.

I hope you enjoyed this post.  Don't forget to follow us on our new Twitter @boomchachalaca and like our facebook page.

The Shorebirds of Coroa Dos Ovos

Well I'm back from Brazil, and excited to start posting again.  As I mentioned, the main purpose of my visit to northern Brazil was as part of a project run by David Mizrahi at New Jersey Audubon to band and flag Semipalmated Sandpipers (Calidris pusilla) on their wintering grounds.  We had a very successful trip, banding 1600 birds in just 8 days of netting.

Semipalmated Sandpipers on Coroa Dos Ovos

The island we were on was called Coroa Dos Ovos, which is Portugese for Crown of the Eggs.  It is a very long sandspit that becomes an island at high tide and connects to the mainland during low tide.  There are several species of regularly occurring shorebirds here such as American Oystercatcher, Whimbrel, Willet, Greater Yellowlegs, Sanderling, Red Knot, Semipalmated, Black-bellied, Wilson's, and Collared Plovers, Short-billed Dowitcher, and of course Semipalmated Sandpiper.  Interestingly enough, all of these species (except American Oystercatcher, Wilson's Plover, and Collared Plover) can be seen feeding in the mangroves at low tide, a behavior that is very difficult for us to imagine in North America.

The tides in this area are extreme.  Low tides expose rich substrate in the mangroves, and create extensive mudflats between Coroa Dos Ovos and the mainland on which the shorebirds forage.  At high tides, birds are pushed up into the mangroves and onto the island to roost.  It was not uncommon to see Whimbrel and Willet roosting in mangrove trees (weird to those of us used to seeing them in salt marsh)!  At extreme high tides, many more birds are forced out of the mangroves to roost on Coroa Dos Ovos.

Whimbrel and Semipalmated Sandpipers roosting in the mangroves

We concentrated our efforts right around the full moon, allowing for the highest tides, and we were not disappointed.  Up to 10,000 Semipalmated Sandpipers, and hundreds of Willets, Whimbrels, Sanderling, and Black-bellied Plover, dozens of Short-billed Dowitcher and Red Knot, and several other species of shorebirds and terns were found roosting on the island.  We caught sometimes more than 300 birds in a night.

One of the Western Sandpipers we captured – an after second year (adult).  Note the dark centers to the back feathers, dark tertials, and little bit of rufous on one or two scapulars (leftover from breeding plumage).

The most exciting part about this was the number of rare shorebirds that could be found in these flocks. While scanning for flagged Semipalmated Sandpipers, I located a Curlew Sandpiper (Calidris ferruginea), and Tom Magarian spotted the first few Bar-tailed Godwits of which we eventually had a high count of 14!  We captured a total of 4 Western Sandpipers, and I found one long-billed individual mixed in with the semis once as well.

Curlew Sandpiper

Curlew Sandpiper

Curlew Sandpiper

Up until last year there were no records for Western Sandpiper on the Atlantic coast of South America (last year our team minus me caught two).  There are not many records for Bar-tailed Godwit for Brazil (not certain of the exact number), but last year the team had the first record for the state of Maranhão with a count of 12 individuals.  There are no published Curlew Sandpiper records for Brazil, but we just found out about a photograph of an individual from 2010.  That makes our bird the 2nd for Brazil, and the first for the state of Maranhão.

Whimbrels and 13 Bar-tailed Godwits (and a Willet that you can't really see)

And again, can you find all 13?

Here's 1-8

...and here is 5-13

And here is the 14th Bar-tailed Godwit, with Whimbrel and Gull-billed Terns (the tern in the bottom left is a Yellow-billed Tern)

~Luke

Off to Brazil

I'm off to Brazil for three weeks to band shorebirds.  I'll post photos and stories when I return.

Take care, and happy birding –

Luke

Photo Study of Semipalmated Sandpipers at Kimble's Beach, NJ

By Luke Musher

As you may know we've been banding lots of Semipalmated Sandpipers, so naturally I've had a lot of opportunities to photograph them.  Here are some recent photos I took at Kimble's Beach in Cape May county, while banding some Semis caught in cannon nets by the international shorebird team earlier this week.

With a Ruddy Turnstone.

Eating tasty horseshoe crab eggs

The word semipalmated means partially webbed.  Here you can see the webbing in between their toes.