Saturday, April 9, 2011

Banding at Fort Morgan, April 6-7, 2011

Fort Morgan is the first land a bird sees after flying over the Gulf

A “Migrant Trap” is a location that tends to concentrate migrating birds.  Fort Morgan, Alabama is a spit of land sticking out into the Gulf of Mexico.  Thus, it is a perfect migrant trap for birds traveling between Central/South America and North America.  The day before I arrived at Fort Morgan, a great number of Ruby-throated Hummingbirds had been captured.  Unfortunately, the two days I spent at the banding stations we only saw 2 hummers and I was not at the right place at the right time to see either of them banded. 

I saw this male hummingbird released after it was banded.
Our second hummer was a female with white tips on a rounder tail

But, I did learn a lot from the banding crew and their wonderful leaders Bob and Martha Sargent of Clay, Alabama.  The grand total for the 2 week spring operation was 70 species, 965 birds, and of those 965, ninety-eight were Ruby-throated hummingbirds.  By comparison, in the spring of 2010 the Hummer/Bird Study Group saw 3485 birds banded.  The difference was wind.  Strong southerly winds helped the northbound birds zip right over the spit of land that is Fort Morgan.  It turns out that what is good for the birds is not so good for the banders.

 The banding of birds is strictly regulated by the Bird Banding Laboratory, a part of the U.S. Geological Survey. (http://www.pwrc.usgs.gov/bbl/index.cfm)  There are currently only 2000 Master banding permits and 3000 subpermits in the United States so banders are a select group of highly trained individuals.

The banding table is set up for accuracy and speed.

 Hummingbird banders are an even more select group, with only about 150 persons in the U.S. and Canada authorized to capture and band hummers.  After watching the Fort Morgan group operate it was obvious to me that the health of the birds was their primary concern.  These master banders and “apprentices” worked swiftly and carefully, to collect data and release the birds as quickly as possible.  

Birds are carried to the table in a lingerie bag for banding and data collection.

 Catching migratory birds involves using a mist net, a fine nylon mesh suspended loosely between thicker supporting lines to form pockets. The mist net was stretched flat between two poles, and birds flew into the nearly invisible mesh where they were trapped. Hummingbirds, however, are seldom captured this way. At Fort Morgan, traps baited with hummingbird feeders were used to capture the hummers.  These operated like lobster or crab traps.  The birds were lured in a trap door by a bright red ribbon or plastic lure and the observant banders were able to capture them before they could find their way out.

This is a mist net. 

This is the kind of hummingbird trap used at Ft. Morgan.

 The captured birds were carried to the banding station in a fabric holding bag (lingerie bag) until they could be banded.  The band for a hummingbird is unique because the bird is so tiny.  Hummingbird bands arrive from the Banding Laboratory as a paper thin sheet of aluminum alloy with printed numbers laser etched into the metal.  The bander cuts band strips from the sheet, smooths, and polishes them and forms a tiny ring using special tools. 

Bob Sargent shows me the tiny hummingbird bands he has formed.
The hummingbird band compared to a penny.  Photo by Tom Wood and Sheri Williamson

 Each band has one letter and five numbers to identify the bird. The band is applied to the tarsus (what we would call the leg) using special pliers.  The band number is unique to the bird it is attached to and any data collected on this bird is sent to the Bird Banding Laboratory.  Vital statistics were quickly collected after banding.  The birds were aged, sexed, weighed, various body parts were measured, and the general condition of the bird was assessed. 

A Yellow-Throated Vireo is banded.

Special magnifying eyeglasses and tools are needed for the work of banding and measuring these tiny birds.  But some of the tools were everyday items.  The birds were kept calm during the banding process in a pantyhose toe (see the scale in picture).  To check how much subcutaneous fat the bird was carrying a drinking straw was used to blow the feathers apart and rate the fat amount.  Remember, many of these birds just flew across the Gulf of Mexico!  They used up lots of stored energy (fat) to accomplish this task, so measuring their stored fat is a good indicator of their physical condition.

Not all the birds caught in the mist nets are migrants.  I was able to hold  this Pileated Woodpecker that was captured.
This entire process of banding took just minutes for each bird.  One person held and measured the bird while the other put the data into the laptop.  The Fort Morgan banding station is a well oiled machine!  The banded birds were released immediately if they showed any sign of stress or were in poor condition.  Birds that were doing well, were released in front of a crowd of onlookers while the banders taught the crowd about that particular species and its’ unique attributes. 

 Through the process of banding, recapture, and recovery we learn about the migration, abundance, and natural history of bird species.  It is great to know there are so many talented volunteers out there who work for and speak for the birds.

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