Monday, July 23, 2012

Marsh Bird Banding on Kiawah Island -- March & April 2012

Clapper Rail -- known to locals as "Marsh Hen" -- Kiawah Island, SC -- Photo credit: Town of Kiawah Island

                Banding birds has this year become one of my favorite volunteer conservation activities.  Thus, this past Spring, when another opportunity to help with banding marsh birds was presented to me by my good friend, Aaron Given, a wildlife biologist for the Town of Kiawah Island, I enthusiastically signed on!  My regular blog readers are already well aware of my bird banding experiences on Kiawah this past Fall.  If you have not yet read these posts, you will hopefully find them elucidative.  Particularly, you will read in Birding Up Close and Personal -- Bird Banding 101 -- Part 1 about the types of data gathered and the informative research that evolves out of that data.  For example, over the years, scientists have been able to track migration routes, conduct species-specific natural history studies, gauge population increases and declines in various areas and from that determine appropriate protocols for helping threatened or endangered species.   In Part 1, I also describe some of the different Lowountry bird banding projects in which I have been involved in the last few years.  In Birding Up Close and Personal -- Bird Banding 101 -- Part 2, I outline the specific goals of the Kiawah Island Bird Banding Project and I explain the procedures used in bird banding with photos of many migratory species banded on Kiawah last Fall.

           This past Spring was the first year for the Kiawah Marsh Sparrow Banding Project which is targeting 3 species of marsh sparrows:  the Seaside Sparrow, ....

Seaside Sparrow -- Kiawah Island, SC -- March 11, 2012

.... the Saltmarsh Sparrow,

Saltmarsh Sparrow -- Kiawah Island -- April 7, 2012
.... and the Nelson's Sparrow.

Nelson's Sparrow -- Kiawah Island -- April 7, 2012

But Aaron will happily band and collect data on any birds that fly into the net, such as the Clapper Rail in the top photo above, or a Marsh Wren.

Marsh Wren -- Kiawah Island -- April 7, 2012
According to Aaron, the objectives for this project include "determining habitat requirements, site fidelity, relative abundance, and distribution of the species."

               Marsh bird banding involves much the same data collecting procedures as a "regular" bird banding station -- identification of species (and if possible, subspecies determination), weighing, sexing and aging, wing measurements, estimation of body fat and stages of molt, etc.

Seaside Sparrow being banded -- Kiawah Island -- March 11. 2012

Andy Harrison recording data -- Kiawah Island -- March 11, 2012

Taking the "nare-to-tip" measurement (nares = nostrils)  on the beak of a Saltmarsh Sparrow -- Kiawah Island
April 7, 2012

Taking a wing measurement on a Seaside Sparrow -- Kiawah Island -- March 11, 2012 

Examining the wing of a Saltmarsh Sparrow prior to measuring it -- Kiawah Island -- April 7, 2012

Examining the wing on this Seaside Sparrow for regrowth of molted feathers -- Kiawah Island -- April 7, 2012

Examining the wing on a Nelson's Sparrow for growth of new feathers -- Kiawah Island -- April 7, 2012 

             The actual netting of marsh-dwelling birds however differs a bit from netting birds on land and requires more physical strength, a knowledge of the ecology of the salt marsh as well as the range and time of the tides.   You see, these species like to stay hidden in the marshes.  Thus a bird bander has to take advantage of an extra high tide in which the rising water pushes the birds to the higher reaches of the marsh grasses closer to shore.  The bird bander selects his net sites based on the ecology of the marsh after surveying available sites at high tide.  This past Spring, Aaron made a trial run on several sites to determine which sites could be the most productive.  This "" site provides a simple explanation of the ecology of the SC salt marshes with drawings, captions, video and photos and I suggest a quick perusal to supplement my description which follows.  

              The area closest to terra firma is known as the Salt Shrub Thicket with shrubs (such as wax myrtle, groundsel), small trees (pines, cedars, yaupons) and grasses.  This area may flood from time to time with higher tides.  Closer to the tidal creeks, you find Spartina grass or cord-grass (the most predominant plant of the salt marsh) growing in thick pluff mud.  This area floods twice a day with salt water from the high tides.  The area in-between with  a harder packed soil (thus walkable whereas pluff mud is not!) is known as the Black Needlerush Zone.  Black Needlerush,  and other plants in this area such as Sea Oxeye Daisy, grow in large clumps on slightly higher ground than the surrounding area.  These plants require an influx of fresh groundwater in order to survive.  During extreme high tides, most of the Spartina is underwater and the birds then rely on these higher hummock areas with these thickly growing plants in which to hide.  Thus it is also here that the bird bander sets up his nets.  In the photo below, behind Aaron and his volunteers, you can see a hummock of Sea Oxeye Daisy in the middle of which Aaron set up a net.  The net was collapsed at this point so that birds would not fly into it while we were banding and collecting data.

Volunteers David McLean (left) and Chris Snook (middle) helping Aaron (right) -- Kiawah Island -- April 7, 2012

                 Unlike netting other birds, you cannot and do not wait for the birds to fly into the nets.  These birds have no reason to leave their safe hiding places in these grasses unless you give them one.  Thus the birds must be herded towards the nets -- hence the physical effort requirement.  The net is placed at the end of a needlerush or Sea Oxeye Daisy hummock, which may or may not be partially inundated with tidal water.  The surrounding area at least should be inundated or the birds are tempted to fly somewhere else.  The bird bander and his volunteers line across the other end of the hummock and then begin to move across the hummock in this line towards the net, clapping and making noises to startle the birds to fly up.  Some of them do not fly up until you are practically on top of them -- so confident they are in their hiding places.  When the birds do pop up, they do not fly far.  They generally will pop back down a short distance ahead of you.  As we, the team, approach the net, we move faster and faster to rush the birds into the nets.  For this post, Aaron provided the aerial images of one of his netting sites which will hopefully help to illustrate the process.  

Aerial image of Marsh Sparrow netting site -- Kiawah Island, SC -- Image credit: Aaron Given

Close-up image of Marsh Sparrow netting site -- Kiawah Island, SC -- Image credit: Aaron Given

            It takes some physical strength to run through the water and the thick grasses in clunky waders.   Heaven forbid that your waders spring a leak (like mine did!)!  If that happens, you cannot run very fast through thick grasses and several inches of water because you are also carrying heavy water in your boots!  Next Spring, I hope to capture some of the action on video to share on the blog.  In the event that I have not yet replaced my leaky boots, I could simply paddle around in my kayak and video tape the action!   I actually do like the part in which we flush the birds towards the net  -- just sans leaky boots!  

           Unlike the Fall Bird Banding site where we were netting migratory birds on their way to another location, these Marsh Sparrow netting sites cannot be used frequently.  The birds become wary of them as they become initiated to the routine.  They soon figure out how to fly over or by the net instead of into the net.  Thus, to monitor fluctuations in the marsh sparrow populations, Aaron plans to survey each selected site only 3 times during the birds' Winter-Spring season.

           Back to the birds!  You may have noticed how similar the different species of sparrows above appear.  This is why birders affectionately refer to sparrows as LBJs -- Little Brown Jobs!  So often, they are hard to identify.  If you cannot determine the species from the field marks on an often obscured, constantly moving target, you simply identify it as an LBJ and you move on.  You cannot put it on your bird list if you cannot identify the species.  No such excuse for the bird bander who has the captured bird in hand!  He has to be able to identify it.  So let's take a closer look at the 3 marsh sparrows found here in the Lowcountry in the winter.

          The Seaside Sparrow(Ammodramus maritimus), a year-round resident, is the largest and perhaps the plainest of these marsh sparrows.

Seaside Sparrow -- Kiawah Island -- April 7, 2012

Although they are relatively common in our area, one subspecies from Florida , the Dusky Seaside Sparrow, is now extinct due to habitat modification.  Another Floridian subspecies, the Cape Sable Seaside Sparrow, from the Florida Everglades, is now endangered.  The Seaside Sparrow seems to be a highly sensitive "indicator" species to the ecological health of the salt marsh habitat.  Considering the amount of development along our coasts, it is gratifying to know that Aaron is working to track the health of this population here.  We rarely see this secretive bird who lives in the tidal zone of our salt marsh where it nests and feeds in the Spartina grass by ground foraging insects, marine invertebrates, seeds and spiders.  A high density population reflects a healthy salt marsh.  Let's hope that Aaron's future research shows our population of these sparrows to be stable.

             The Saltmarsh Sparrow (Ammodramus caudacutus), ....

Saltmarsh Sparrow -- Kiawah Island, SC -- April 7, 2012

.... formerly known as the Saltmarsh Sharp-Tailed Sparrow, was once considered as the same species as the Nelson's Sparrow (Ammodramus nelsoni), formerly known as the Nelson's Sharp-Tailed Sparrow.  Recently, however, the species have been split and the "Sharp-Tailed" nomenclature has been dropped.

Saltmarsh Sparrow -- the photo shows why it was once called "Sharp-Tailed" -- Kiawah Island -- April 7, 2012

Scientists have determined that these 2 species differ in their breeding ranges, songs, genetic make-up and plumage characteristics.  The Saltmarsh Sparrow breeds along the Northeast coast of the United States south as far as Virginia and winters primarily along the North and South Carolina coasts.  They are ground nesters and their nests are susceptible to extra high spring tides and storms.  Pairs have more success if they are able to re-nest during the new moon phase.  They, like the other marsh sparrows, are rather secretive. They also forage on the ground in thick grasses for insects, spiders, marine invertebrates, and some seeds.  They are considered to be common, but vulnerable to development. 

             The Nelson's Sparrow (Ammodramus nelsoni) .....

Nelson's Sparrow -- Kiawah Island, SC -- Marsh 11, 2012
..... breeds in freshwater marshes and wet meadows in the interior of Canada and the Northern United States as well as in brackish marshes along Hudson Bay, Novia Scotia and Maine.  It winters along the Gulf and East coasts of the United States from Virginia southward.  It forages for its food (spiders, insects, snails, and seeds) on the ground like the other species and it also builds it's nest on the ground.  Again, secretive like the other marsh sparrows, it is hard to see but it is considered to be common with a seemingly stable population.

             It takes a talented, well-practiced bird bander, with an eye for minute details, like Aaron Given, to be able to distinguish a Nelson's Sparrow (Ammodramus nelsoni) from a Saltmarsh Sparrow, and then to also classify the bird into one of the three different subspecies of Nelson's which inhabit our marshes in the winter.  The three subspecies areAmmodramus nelsoni nelsonii, Ammodramus nelsoni alterus, and Ammodramus nelsoni subvirgatus.  So let's try a little test.  See if you can match the following descriptions, provided to me by Aaron, to the three photos (A, B, and C) below.

....Nelsonii is brighter and more contrasty in plumage colors overall.  Subvirgatus is washed out and dull in color.  Alterus is kind of in between but there can be some overlap between nelsonii and subvirgatus and not all birds can be reliably identified to  subspecies.   

More specifically, I look at the flanks, crown, back, auricular patch to distinguish between the subspecies. 

Nelsonii = flanks are dark (sometimes black) and the streaking is very distinct;  crown is strongly patterned with heavy black streaking in the lateral stripes with a thin gray median stripe that is often obscured by black from the lateral stripes; back is strongly patterned, scapular feathers have large black centers strongly contrasting with whitish fringe.  Auricular patch usually dark and contrasting with bright orange face.

Alterus = flanks are grayish and the streaking is indistinct and blurred;  Narrow but distinct black lateral stripes with obvious broad gray median stripe; the back is weakly patterned  with little to moderate development of black with grayish fringes in scapulars; Auricular patch grayish contrasting with orangish or yellowish face. 

Subvirgatus = flanks very indistinct and blurred;  crown weakly patterned, median stripe dull grayish not strongly contrasting with brownish lateral stripes (black in lateral stripes absent or nearly so); Back is weakly patterned with dull olive-gray tones.  Small black centers in scapulars contrasting with pale edges.  Auricular patch is dull gray weakly contrasting with the dull buffy face. Subvirgatus also averages larger than the other two.

Photo A:

Ammodramus nelsoni ______? -- Kiawah Island -- Spring 2012 -- Photo credit: Town of Kiawah Island

Photo B:
Ammodramus nelsoni ______? -- Kiawah Island -- Spring 2012 -- Photo credit: Town of Kiawah Island

Photo C:
Ammodramus nelsoni ______? -- Kiawah Island -- Spring 2012 -- Photo credit: Town of Kiawah Island
Here now the answer is in Photo D.  The exact same three birds above were photographed together.  CAn you tell which one is which?

Photo D:
The Ammodramus nelsoni trio from left to right: A. n. alterus, A. n. nelsonii, A. n. subvirgatus -- Kiawah Island -- Spring 2012 -- Photo credit: Town of Kiawah Island
If you are still struggling with the IDs and the differences are still not obvious, do not worry.  It takes practice.  I certainly need frequent confirmations in the field myself.  And, once at home, I also e-mail Aaron  (having done so multiple times for this post in  particular) with  ID questions on my own photos.  After all, they are LBJs.  So the answers to Photos A, B, and C follow:

Photo A:  Ammodramus nelsoni alterus
Photo B:  Ammodramus nelsoni nelsonii
Photo C:  Ammodramus nelsoni subvirgatus

Another interesting tidbit that I learned from Aaron about these three subspecies of Nelson's is that they have distinct, non-overlapping breeding ranges: the alterus  breeds in James Bay; the nelsonii breeds in interior northern prairie;  the subvirgatus breeds along the North Atlantic coast. 

              Different subspecies of  Marsh Wrens (Cistothorus palustris) also inhabit our marshes in the winter.

Two subspecies of Marsh Wren -- Kiawah Island -- March 11, 2012

One of the birds is from one of two subspecies --  either Cistothorus palustris dissaeptus or Cistothorus palustris waynei -- that migrate from parts North and spend the winter here in SC and points further south.  The other is our non-migratory subspecies, Cistothorus palustris griseus, also known as Worthington's.  Can you recognize one of these as our local bird?

Bird on Left:  either C. p. dissaeptus or C. p. waynei  //  Bird on right:  C. p. griseus -- our local Worthington's
Kiawah Island -- March 11, 2012

So the caption above gives the answer.  You can see that the larger, more colorful bird on the left is the visiting bird (the tourist) and, on the right, is our drab little local bird, sort of the color of pluff mud!  He is a feisty little fellow though!

           The part of the bird banding activity that first-time volunteers often enjoy the most involves releasing the birds.  Of course, I like to photograph them holding their birds prior to release!

Andy Harrison holding a Nelson's Sparrow -- test: which subspecies is it? -- Kiawah Island, SC -- March 11, 2012

               The bird bander himself enjoys contemplating each beautiful little bird!

Aaron and a Marsh Wren ready for release -- Test:  Which subspecies is this? -- Kiawah Island, SC  -- March 11, 2012

               Of course, it goes without saying that the bird's favorite part is the release.  As a photographer, I hope to some day capture the bird's takeoff.  It will take split-second timing to get the best possible, in-focus shot.  It would help if the birds would actually fly when you open up your hands.  Most do!

Seaside Sparrow -- Time to go! -- Kiawah Island, SC -- April, 7, 2012

But, occasionally, some of them hesitate and think about it....

The same Seaside Sparrow -- Again, it's time to go! -- Kiawah Island, SC -- April, 7, 2012

When that happens, you have to anticipate when they will leap (?!).  Well, I still have no photo to show you of the take-off.  I will keep working on it!

Once released, some birds fly a very short distance and then glance back at us.  I can imagine what they might say to us ...

Nelson's Sparrow -- Kiawah Island, SC -- April 7, 2012

Nelson's Sparrow in the Sea Oxeye Daisy -- Kiawah Island, SC -- April 7, 2012

          Birds are banded, data is collected, birds are released and the tide is going out.  That brings another morning of banding birds to a close.  That also brings this post to an appropriate point for closure.  What a long post this was!  I feel as though I have produced a major research paper -- which is much more fun when it is not for a grade!  Although I do confess to a bit of procrastination on this post -- much like what occurred for those research papers of the past!  Also, just like those research papers and projects from my student days, I have learned so much!  Each little piece of information leads to another question which then requires more investigation.  I hope too that I have  helped some of you learn as well.

         Finally, I want to end this post by wholeheartedly thanking Aaron for the opportunity to participate in the bird banding project on Kiawah, as well as for his guidance, photos, references, other images and expertise in the production of this post (and the previous posts on bird banding!).   And thank you also, Aaron, for being such a patient and generous mentor.  Just so you know, I am ready to help band birds again!

Greenlaw, J. S. and J. D. Rising. 1994. Sharp-tailed Sparrow (Ammodramus caudacutus). In The Birds of North America, No. 112 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists'™ Union.

Kroodsma, Donald E. and Jared Verner. 1997. Marsh Wren (Cistothorus palustris), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:

 Post, William, W. Post and J. S. Greenlaw. 2009. Seaside Sparrow (Ammodramus maritimus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:

Post, W., and J. S. Greenlaw. 1994. Seaside Sparrow (Ammodramus maritimus). In The Birds of North America, No. 127 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists'™ Union.

Pyle, Peter.  1997.  Identification Guide to North American Birds, Part 1.    Point Reyes Station, CA: Slate Creek Press.

Sibley, David A.  2003.  The Sibley Field Guide to Birds of Eastern North America.  New York: Alfred A. Knopf, a division of Random House, Inc.

Smith, Fletcher M.  2011.  Photo Essay: Subspecies of Saltmarsh Sparrow and Nelson's Sparrow. North American Birds, 65, 368-377.  Retrieved from

1 comment:

  1. Fabulous post. Very informative and inspiring. Well done.

    Mark Whitaker