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Wednesday, December 18, 2013

Three Wintering Rufous Hummingbirds in East Tennessee

Sunday, December 15th, was a cold and windy day, creating considerable discomfort at times as I accompanied Jane and Mark Armstrong on their travels to band three wintering hummingbirds.  Without a doubt, the reward of seeing three of these hardy birds in one day far exceeded the discomforts of early hours and occasional numb fingers. 
Take a look at the image above and the two directly below it and you'll see how different each of these wintering Rufous Hummingbirds appeared.
In the top image you see a mature female Rufous Hummingbird (Selasphorus rufus) with a large number of gorget feathers on her throat and thick feathering on her brow. Directly above, appearing quite different, an immature female is pictured.  And below, an immature male Rufous Hummingbird in his first winter season after hatching.
Each of these wintering birds was located in a different county in Tennessee, and captured and examined by Mark Armstrong, east Tennesee's Master Bander of hummingbirds, and assisted by Jane, who helps with the set up and records the data Mark collects.
Once the trap is in place with the feeder inside it, Mark sits quietly, a distance away from the feeder, with a fishing reel in hand.  The line on the reel is attached to a wire door on the trap that slides up and down, and can be lifted with tension on the line, or lowered with the release of tension once the hummingbird is inside the trap. In the above image, Mark is removing the captured hummingbird from the trap.
The morning was overcast and 33 degrees F with 4 mph wind gusts, making sitting still outside for any length of time very cold.  After briefly rubbing his hands together to stimulate some warmth, Mark opened the bag to examine the hummingbird that had been visiting Janet and Bob Cushman's feeder in Roan County since approximately October 27th.  The couple noticed a difference in this bird that lingered behind after their Ruby-throated Hummingbirds had departed.      
To Mark's surprise and excitement, he found a band on this hummingbird's leg!  The band series indicated it was not one of Mark's bands, meaning the band had been placed on the bird in another geographic area. The recovery of a band is great news for a bander and is actually what banding is all about.  Once the banding data is retrieved, Mark will know more about this bird's age, where she has been before arriving in Tennessee, and if lucky, perhaps her breeding area.
Above, Mark is measuring the hummingbird's wing.  Wing measurements, as well as tail measurements, are important in distinguishing similar hummingbird species.  The Eastern migration of Rufous Hummingbirds has been studied for many years, with the first record of a wintering Rufous species in the eastern United States reported in Charleston, South Carolina, in 1909.
Above, Mark measures the beak length with a digital instrument.

During the fall of 1988, Bob and Martha Sargent began studying wintering hummingbirds in Alabama, Georgia, Forida, Mississippi, and Tennessee, compiling reports of these birds, and when possible, banding them.  Comparing records from past years, and their compilation of reports from the six winters from 1990 to 1996, in just this five state region, 1,643 Selasphorus hummingbirds were reported (Broad-tailed, Rufous and Allen's species) during winter months, showing a substantial increase in numbers.  95% of those recorded were Rufous Hummingbirds.

In the images above, Mark is using magnification to examine the beak for grooving.  Grooving indicates the bird is immature and still in its hatching year.  This female inidividual had no grooving in her beak which means she is a mature bird.  It is possible the banding data, once retrieved, may identify her age more specifically.
Above, Mark makes an approximate count of her gorget feathers, and Jane records the data below.
Rufous hummingbirds breed and spend their summer months in the western states.  Very little is presently known about where these wintering hummingbirds are breeding and what route they may be taking as they reach Tennessee.  Some may be passing through Tennessee en route to other areas.
Mark places the hummingbird in Janet's hand for release.  Janet recently reported that their female Rufous has been visiting the feeders in the two days since her capture, though she visits less frequently during warmer periods.

Next:  Our second stop, a juvenile female

Links and Resources:

Western Hummingbirds Wintering in Tennessee
Allen's Hummingbird in Tennessee
Rufous Hummer in Knoxville 
In recent years, fourteen species of hummingbirds have been documented in the east during fall and winter months.  In east Tennessee, report sightings to Mark Armstrong at Woodthrush@bellsouth.net or 865-748-2224.  For a list of contact information for other eastern areas, visit winter reporting on the Hummer Study Group website or report sightings to Bob and Martha Sargent, Rubythroat@aol.com or 205-681-2888.
Other blog posts on Wintering hummingbirds in Tennessee
Visit Bob Sargent's information on wintering hummingbirds
Bob Sargent describes the Rufous Hummingbird as very cold-hardy.
Sargent on wintering Calliopes and the Allen's Hummingbird
Hummingbird banding
Hummingbirds in watercolor
Hummingbird art on Vickie's Sketchbook blog
Cornell's All About Birds:  Rufous Hummingbirds

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