Monday, October 24, 2011

Birding Up Close and Personal -- Bird Banding 101 -- Part 2

In Part 1 of this series, "Birding Up Close and Personal -- Bird Banding 101," I cover the question of why band birds and of my limited volunteer opportunities thus far in the local bird banding world.  And I promised to write more specifically in Part 2 of my recent experiences of banding birds with Aaron Given, wildlife biologist for the town of Kiawah Island.  As I stated in Part 1, one of my motivations for helping Aaron with the bird banding is that it is migration season and I want to be able to see and learn more about some of the migrants as they pass through.  As Aaron helps me to learn about the birds he catches in the mist nets, I can in return help him in the banding process!

Wanting to obtain a complete picture of the goals of this Kiawah Island Bird Banding Project, I asked Aaron to outline those for me.  Here is his response:

The goals of fall migration bird banding project on Kiawah Island are to:

  • Gather baseline information on resident and migratory birds on Kiawah Island.
  • Collect data to enable long-term monitoring (i.e. population tends) of birds on Kiawah Island.
  • Monitor fall migration to determine the importance of Kiawah Island as stop-over habitat.
  • Assess the effects of development on bird populations.
  • Provide data to better manage habitat and guide future development plans.
  • Contribute high quality data to the North American Bird Banding Program. 
 Specific data on the birds banded and other information on this project, as well as other bird banding and wildlife projects ongoing on Kiawah are explained in-depth on their site, Wildlife on Kiawah Island.  I fully recommend taking a look at this site.  The Kiawah biologists' work is impressive.

So far, I have volunteered 3 times this month -- October 2, 15 and 22 --  at  Aaron's bird banding station on Kiawah Island on Captain Sam's Spit on the west end of the island.  We arrive at dawn on the beach -- ah the beauty of the morning light out on the ocean -- the royal blue of the sky and the thin orange line on the horizon above the dark water are only interrupted by the bright lights of the shrimping trawlers offshore!  And as we unload the truck with the gear, we can hear the chirps of  the many traveling birds coming in off of the ocean or those already resting in the dunes and behind.  The banding table is under the cover of a wax myrtle grove.  We have to hurry out to the field to set up the mist nets before the birds begin to move about to feed.  The mist nets are placed in a "lane," an area where birds would fly across an opening in the foliage from one perch to another.  The very light nylon threads are very difficult to see and are practically invisible for the birds who fly into the nets and are then trapped in the net pockets.  Aaron has several lanes and nets at his disposal and will open those nets where the wind is low.  The picture below shows one of the mist nets.  Aaron is looking back at an escapee -- a House Wren that slipped through his fingers as he was removing it from the net.

Mist net -- October 15, 2011
The nets are in place by 7:30 am, just in time, since in a busy migration season, this is the most active time -- the birds are moving!  We rotate through the nets again to extract birds.  Once we have a bird in hand, we place it in a bird pouch and continue to remove more birds from the net.  With birds removed from the nets, we head back to the banding table.

Aaron returning with many bags of birds! -- October 15, 2011

Banding table with bags of birds waiting to be processed -- June 15, 2011
Processing the bird involves first an identification of the species which allows for the appropriate selection of the correct band size.  The bird species and it's new unique band number is read to the recorder who notes it on a data sheet.  Next the bander opens the band so that it can be placed around the bird's leg and then closed again.

Aaron and Sophia, a volunteer and resident of Kiawah Island, banding and recording -- October 2, 2011

Preparing a band -- October 22, 2011

Next, the band is tightened around the bird's leg.  The bands are extremely light weight aluminum and so they do not hinder the bird in any way.  And it fits like a bracelet.

Yellow-billed Cuckoo receiving his "Bling!" -- October 15, 2011

Black-Throated Blue Warbler receiving his "Bling!" -- October 22, 2011

After the band is attached, the bander then determines the fat, sex and age of the bird.  The amount of fat is critical to long distance flyers.  Many birds make their migratory routes in stages, fattening up in different locations along the way so as to have enough fuel to burn for a longer flight.  Fat levels range from 0 to 5 with 5 being the fattest.  A fat level of 0 is a likely indicator that the bird has recently arrived on site from a long overnight journey and needs to pack on more weight before he can commence the next leg of his migration.  Fat levels are determined by blowing onto the bird's chest to spread the feathers away so that the skin and breast are revealed.  A trained bander knows what each level of fat looks like and will call the number out to the recorder.

Aaron is determining the fat level of this Common Yellow-Throat -- October 22, 2011
Aaron is performing a "fat check" on this Tennessee Warbler -- Oh, the indignity of it all! -- October 15, 2011

The next step in data collection is to age and sex the bird.  Even for those dimorphous birds, this is not always easy because many hatch year juvenile males will have a coloration similar to an adult female.  A thorough knowledge of slight variations in coloration of certain feathers and of molt stages is key to determining sex and age.  Adults and hatch year juveniles do not molt at the same times nor do they molt in the same amount.  So their feathers will show different amounts of wear depending on the time of year.  A female Yellow-Rumped Warbler (the Myrtle variety) will show less blue tones in certain feathers than any male Yellow-Rumped Warbler.  A hatch-year male American Redstart will have very bright yellow-orange spots in it's "armpits" whereas an adult female's "armpits" (or perhaps "wingpits" is a better word) will be a paler yellow.

Checking feathers for degrees of molt and for slight differences in coloration on a Tennessee Warbler -- October 15, 2011

So which is it -- adult female Indigo Bunting or a hatch year male or female? -- October 2, 2011

In the introduction photo at the top, Aaron was explaining to me the differences in wear visible in the tail feathers between an adult male American Redstart and a juvenile.  Often, age and sex  differences can only be determined with the bird in hand.  Wing length can also be an indicator of the sex in certain species.

Taking a wing measurement on a Northern Waterthrush -- October 15, 2011
Measuring a Veery's wing -- October 2, 2011

Occasionally, Aaron has to check his in-depth on-site resources when he encounters a species with which he has less experience.  Our standard birding field guides, for the sake of portability, often lack details in describing all the subtle differences between species, particularly in females.

Checking a warbler reference on feather coloration for a  female Tennessee Warbler -- October 15, 2011

Finally, the bird is weighed (in grams, of course) and the weight is recorded before release.

Common Yellow-Throat being placed in the cup in order to be weighed -- October 2, 2011

Gray Catbird weighing at a healthy 37 grams! -- October 15, 2011
Recording the data -- October 22, 2011

 Before releasing the birds, we sometimes do a photo shoot (if we like the bird and if we have not already processed multiple birds of the same species!)  So here are some of our favorite birds!

First, the thrushes!  Four different species of thrushes have come through the banding station on the times that I have volunteered.  I have often been frustrated by these birds since  I have encountered many of them only once or twice in my birding experience.  They are so similar in appearance that I have often become confused about their differences.  But when you have the opportunity to "bird up close and personal" with an expert, much of it becomes very clear.  So here they are, my much coveted thrushes!

Veery -- October 2, 2011

Wood Thrush -- October 2, 2011
Wood Thrush -- October 2, 2011
Swainson's Thrush -- October 2, 2011
Gray-Cheeked Thrush -- October 22, 2011
Gray-Cheeked Thrush -- October 22, 2011
Gray-Cheeked Thrush -- October 22, 2011
Aaron verified that this was not a Bicknell's Thrush by a wing measurement.  These 2 thrushes are very similar and a wing measurement simply is not possible in the field, now is it?  So, there's another one which will remain mysterious for me.

Another bird with similar coloration but which is much smaller is a warbler, the Ovenbird -- another personal favorite for me!  I love their striped caps!

Ovenbird receiving his "Bling!" -- October 2, 2011
Ovenbird ready to go! -- October 2, 2011
Ovenbird! -- October 2, 2011

Here is another little brown bird in a rather plain wrapper -- the House Wren.  And yet, I find it simply beautiful!  I love the subtleties in the coloration of its tail and wing feathers! 

House Wren -- October 2, 2011

Who does not love the White-eyed Vireo and the Blue-Headed Vireo?

White-Eyed Vireo -- October 2, 2011
Blue-Headed Vireo -- October 15, 2011

 On October 15, this Black-Throated Green Warbler is the first to have been seen or banded on Kiawah according to the Aaron's bird records.  Since this day, he has banded another one!

Black-Throated Green Warbler -- Aaron's favorite bird of the day -- October 15, 2011

For October 15, my best bird of the day and my favorite bird of the day are 2 different species.  My best bird was of course a life bird for me -- the nondescript Tennessee Warbler.

Tennessee Warbler -- Life Bird for me! -- October 15, 2011

 But my favorite bird of the day is this gorgeous Black-Throated Blue Warbler!

Black-Throated Blue Warbler -- My favorite bird of the day is READY TO GO! -- October 15, 2011

I was thrilled to be able to remove this other handsome warbler from the net -- a male American Redstart!

Adult male American Redstart -- October 15, 2011

Other good birds of the day for October 15 were the House Finch, a first time banding of this species this year on Kiawah, and the lovely female Hooded Warbler.

House Finch -- October 15, 2011
Female Hooded Warbler -- October 15, 2011

In September and early October, the predominant bird banded each day was the Common Yellowthroat.  Then by mid-October, their numbers were dropping off.  So on October 15, Aaron was telling me that we needed to band 10 of them that day to reach the 500th one for the season.  And sure enough, this very handsome male Common Yellowthroat -- our last of the day was indeed the 10th one for the day and the 500th Common Yellowthroat banded this Fall season!   

Common Yellowthroat -- Number 500 for the Fall 2011 banding season -- October 15, 2011

On October 22, we banded 3 lovely Yellow Palm Warblers.

 "Yellow" Palm Warbler  -- October 22, 2011
"Yellow" Palm Warbler -- October 22, 2011

And now it is time to tell the stories (in photos) of the funny birds!  I will start first with the fired-up Ruby-Crowned Kinglet who did not appreciate having his crown stroked.

Ruby-Crowned Kinglet  -- "So you are a boy!" -- October 22, 2011
Ruby-Crowned Kinglet -- "Not digging the photo shoot!" -- October 22, 2011
Ruby-Crowned Kinglet -- "REALLY?!  Just how many pics do you need?" -- October 22, 2011

Then, a bander needs to know which species are bite-y.  This is really not too hard to figure out.  The birds know whether or not they have an effective tool at their disposal -- these are the species that have the strongest jaws.  The ones that can bite hardest, bite more.  The Northern Cardinals, whose bite can break skin, are the bite-iest.  White-Eyed Vireos' and Painted Buntings' beaks are much weaker but they can still give you a good pinch.  So do not be fooled by the lovely, serene appearing Painted Bunting below.  She was quite a feisty biter!

Painted Bunting -- October 22, 2011
  As was this noisy young guy.  Not all painted buntings protest loudly the banding process, but this one did!

Hatch year male Painted Bunting -- October 2, 2011
This Painted Bunting is ready to go but first, vengeance is sweet!  -- October 2, 2011

Another species that almost always protests loudly and is very happy to bite is the Gray Catbird!  What a great bird!  This fellow below was the best of the bunch!  When released, he stayed in Aaron's hand and latched onto his finger. Not once, but twice, Aaron had to tug his finger out of the bird's beak.  I am sorry that I missed those shots!  Then the bird still did not leave, but just perched on Aaron's hand studying us.  Let's just hope that he does not have a Raven's memory for faces!

Gray Catbird -- studying his "captors" before he leaves -- October 15, 2011
The bird finally did leave but he did not go far.  He moved about the branches of the wax myrtle grove under which we sat, still studying us.  Was he plotting a revenge?

My last funny bird was the Yellow-Billed Cuckoo!  First, he made a sort of gurgled, cooing noise.  I am just not all that familiar with the possible sounds that this species can make.  But it was kind of weird.  It certainly did not sound like any kind of alarm call such as the screech of many other species.  He certainly was a handsome bird!  I love how they allow their wings to hang down. 

Yellow-Billed Cuckoo -- October 15, 2011
  This bird also was not anxious to leave the banding site.  He hung out in the wax myrtle peaking back at us for quite a while.  Goofy bird! 

Yellow-Billed Cuckoo -- contemplating us and what just happened to him -- October 15, 2011

Many thanks to you, my expert birding buddy, Aaron, for allowing me to participate and learn in your Fall Migration Bird Banding Project and for allowing me to share it with readers of Pluff Mud Perspectives.  I look forward to more of this "Up Close and Personal" kind of birding!

Sunday, October 23, 2011

Birding Up Close and Personal -- Bird Banding 101 -- Part 1

Fall migration here on the coast proves to be a rather bird rich experience as well as, sometimes, a frustrating one.  This seems particularly true when you read about your fellow birders seeing a rare and wonderful species.  And yet, every time you show up at that particular wood pile, the much touted Clay-Colored Sparrow is a no-show!  Perhaps those fabulous rare migrants were there and I just missed them because, as a relative novice, I still cannot recognize them.  My solution in these cases is to pair up with a more expert birding buddy to help me see the birds.  This Fall, I have determined an even better solution -- volunteer to help an expert birding buddy to band birds in what is normally an off-limits bird-rich environment!  Hello Aaron, I am here to help!

My friend, Aaron Given is a wildlife biologist for the Town of Kiawah Island which partners with the Kiawah Conservancy, a Land Trust Alliance member, working to preserve natural habitat areas of Kiawah Island.  They have supplied funding for his bird banding activities on Kiawah Island.  He has been banding birds on Kiawah for the past 3 years.  My recent volunteer banding activity with Aaron on Kiawah has inspired this 2 Part Series on banding.  Part 1 will give you an overview of bird banding research.  Then in Part 2, I will share specifically the wonderful Fall migrants I have seen up close and personal as well as the details of the banding activity at Aaron's bird banding station.

So what is bird banding all about?  The best place to find answers to that question is The Bird Banding Laboratory (BBL), a program of the US Geological Survey (USGS) Patuxent Wildlife Research Center.  First, historically, bird banding has been occurring for hundreds of years and the BBL site gives a good overview with interesting tidbits into that history.  For example, I learned that Henri IV's (of France, bien sûr) banded Peregrine Falcon flew off in pursuit of a Bustard and was found 24 hours later on the island of Malta -- a distance of approximately 1350 miles away!

The next and perhaps most important question is why?  For the detailed answer, I suggest you study the information in this link (and for even more details, this one) to the BBL site.  And I will try to summarize to give you the short and sweet and also show you some of the prior banding efforts for which I have volunteered on occasion.

First we learn about migration routes and the dispersal of species.  For example, through bird banding data, scientists have been able to establish that the Arctic Tern has the longest, and perhaps most amazing, migration -- 25,000 miles round trip from the North Arctic to the South Arctic.

Map copied from the BBL site showing migration corridors determined in part through banding data.

Also, researchers may have a specific population study to conduct for which they may be trying to determine a species' behavior and social structure.  This is the type of study being conducted in SC Audubon's Project Protho in the Francis Beidler Forest.  In this citizen science project, Prothonotary Warblers have been banded with the usual federal metal band with their own unique ID number as well as with a unique combination of plastic colored bands which makes each bird identifiable without the need to recapture the bird.  Now by observing the individual birds in their habitat, they are learning about site fidelity, mate fidelity, reproductive behaviors, territory size of this species, etc.

Prothonotary Warbler in Francis Beidler Forest -- June 2009

Prothonotary Warbler in the Francies Beidler Forest just after banding -- April 2009

Banding also allows scientists to determine life spans of different species.  You can see some particularly interesting longevity records published on the BBL site.

The survival and productivity of species are also studied through the Monitoring Avian Productivity and Survivorship (MAPS), a cooperative effort, banding program of the Institute for Bird Populations and banders throughout North America.  Banders at The Avian Conservation Center and The Center for Birds of Prey in Awendaw, SC participate in this effort every summer by setting up mist nets, banding, collecting physical data on captured birds before releasing them.  Analyses of the data provide critical information on the ecology of land bird populations, as well as factors responsible for changes in their populations.  Using  this data, conservation and management decisions are made.  On a few of occasions over the past 2 summers, I have volunteered in that effort.

Carolina Wren's wing being measured -- June 2010

Eastern Towhee being measured for his band -- June 2010

Eastern Towhee receiving his "bling!" -- June 2010

Banding data also helps scientists to conduct toxicology and disease researchAdditionally, an annual analysis of banded game birds is conducted to determine the best land management and best hunting regulations for sustaining viable populations.  

So how many birds have been banded?  The BBL has data going back to 1914 but they only have data in electronic format back to 1960.  Since 1960 up to January 2011, the lab has received over 64 million banding records.  And in the past decade, the lab has received on average 1.2 million banding and 87,000 encounter records per year.  You can see more details and retrieve specific data by visiting this link as well as this one on the BBL site.

I hope you will take the opportunity to explore some of the links above to the BBL site.  What we can learn from bird banding data is extensive and fascinating.   And it has the ultimate goal of supporting bird life!