Hardy Hummingbirds Survive the Polar Vortex Plunge

On January 13, I accompanied Mark Armstrong to another hummingbird banding in Knoxville, Tennessee, just six days after local temperatures plunged to a record low of 2° F during the Polar Vortex.

Photo credit:  Mark Armstrong

A wintering hummingbird was discovered at the home of Christal Pettit early in October.  Soon after she had taken her feeders down thinking all the migrating Ruby-throats had left, her husband noticed a hummingbird hovering in an area where a feeder once hung.  Krystal quickly made nectar and hung a feeder out and her wintering hummingbird has been steadily present since.

Christal (left) and her daughter, Evan, watch as Mark Armstrong, Master Bander of hummingbirds bands the hummingbird and measures its wing, tail, and beak.  Each of these measurements give the bander information about the gender and species of the hummingbird, in this case, a mature female Rufous.

Mature females look alike in the three Selasphorus species which include the Broad-tailed, Rufous and Allen's hummingbirds. They each have green feathered backs and, usually, a cluster of reddish-orange gorget feathers on their throats.  The Rufous species is by far the most commonly found wintering hummingbird in Tennessee and in the eastern United States.

Mark uses a straw and blows the feathers away from the belly to assess the amount of fat the hummingbird has stored.  This hummingbird's fat was rated a "one" with zero indicating no fat deposits, and she weighed 3.9 grams, a healthy weight for this species.  This means she is receiving enough nutrition to not only nourish herself, but to store fat reserves for later use.  

Additionally, this mature female was molting feathers--losing worn feathers and growing new ones to replace them.  In the image above, you can see the three brownish old feathers with frayed ends on the left compared to her new grayish feathers with smooth edges.  She was also showing new feather growth on her body and head. Molting, in general, is a sign of good health and nutrition and Mark commented that this bird was molting more heavily than he had seen in other hummers he's captured this season.

Photo credit:  Mark Armstrong

Above you can see the Rufous female tail feathers compared to the male's tail feathers shown in my previous post.  Females have white tips on their three outer tail feathers on each side.  The white tips lack pigment, which adds strength to feathers, and are worn more easily during the process of nest building and feeding young during the breeding season.

Above, Mark and Christal give the hummingbird a drink before she is released.

It is a joy to meet the people who host these wintering hummers and to share in their excitement about their visitors.  To date, Mark has banded nine Rufous hummingbirds in east Tennessee and recaptured four--three that he previously banded, and one bird that was banded in Tallahassee, FL last year as a juvenile. Recapturing a bird after it is banded enables researchers to learn more about the age, health and migration patterns of the hummingbirds that are migrating east for the winter.

Photo credit:  Billie Cantwell

Other reports on area hummingbirds varied after the severe weather front moved through. Billie Cantwell and Colin Leonard's male hummingbird, that first began wintering at their home in 2011, continues to frequent their feeder.  The above image, taken several days after the severe weather, shows the light arrangement that Billie and Colin hung over the feeder to keep the nectar from freezing.  The light is a 150 watt flood light or spot light that is non-LED and gives off heat.  When temperatures were in the single digit range, Billie moved the feeder closer to the lamp; when the temperature moves up to 17 F or higher, the feeder is hung farther away.

Photo credit:  Jon Dempersmier

Above, another female hummingbird continues to winter in Seymour, Tennessee, and was photographed at the feeder by Jon Dempersmier January 8th, the day after the record cold.  Though Mark has not recaptured this bird, yet, she wears a band and is likely the Rufous female that he banded at Jon's home last season.

Photo credit:  Katheryn Noblet

The adult female Rufous, above, that made a fall migration stop-over at Katherine Noblet's home in Johnson City, departed prior to the severe weather and was last seen on December 4th.

Photo credit:  Marnie Mitchell

The mature male Rufous pictured above has been wintering in Smithville, TN, at the home of Tommy and Virginia Curtis, and was seen frequenting the feeders following the severe front.  He departed on January 9th, likely, to resume migration.

Photo credit:  Wally Manspeaker

The image above was taken on January 6th, in Russellville, TN, as the artic air was approaching with high winds that rocked the feeder and brought windchills of -14 degrees F in east Tennessee.  Wally's female Rufous was among the several that were not seen on January 7th, the morning of the lowest temperature drop.  Included in this group were Sherry Ladd's mature male Rufous, Candy Casey's adult female Rufous, and Jim Turnblazer's juvenile female Rufous.  

Candy Casey wrote a letter to Bob Sargent on January 7, asking about the disappearance of her bird, fearing that the female Rufous had perished in the cold as the front moved in.  His response was interesting and reassuring.

"Twenty-five years of banding records tell me that most ADULT Rufous, male or female, tend to leave their primary winter site(s)...between December 15 and January 15.  If they leave earlier than that, it is...in my opinion, because their easy supply of tiny bugs and spiders has been diminished.  This occurs often when winter deepens.... I would bet the farm that your little cold-hardy female Rufous has gone south and then will turn westward toward her nesting grounds in Washington, Oregon, British Columbia or maybe even SE Alaska.  Don't take your feeder down just in case she's hanging out somewhere close,  In my opinion she is not likely to be dead but merely moved on to the south or southwest."

Many of us will be watching for the return of these birds next fall and looking forward to re-capture reports that will affirm their survival and successful migration.  It is clear that this hardy strain of eastern-migrating Rufous hummingbirds is challenging our notion of hummingbird frailty and raising many questions about their winter survival strategies.

In east Tennessee, report winter hummingbird 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.

Links and Resources:

What is a Polar Vortex?
Climate Change and the Polar Vortex

Western Hummingbirds Wintering in Tennessee
Allen's Hummingbird in Tennessee
Rufous Hummer in Knoxville 
Other blog posts on Wintering hummingbirds in Tennessee
In recent years, fourteen species of hummingbirds have been documented in the east during fall and winter months.  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
Bird Banding Laboratory
Birds of North America--I highly recommend subscribing to the online version for detailed descriptions of all North American bird species.

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

Pretty Rufous Hummingbird Female Banded in Erwin, Tennessee

Wintering Rufous hummingbirds are being reported throughout east and middle Tennessee, and have been arriving since August, keeping Mark Armstrong, the Master Hummingbird Bander in the eastern part of the state, very busy.  

I had the pleasure of accompanying Mark and his wife and assistant, Jane, as they traveled the two hours to northeast Tennessee on November 24th to band wintering hummingbirds.  Our first stop was Erwin, TN, to visit with Candy Casey (below) who is a new birder and was excited about her first opportunity to see a hummingbird upclose.  

In the image above, Mark is opening the mesh bag that holds the hummingbird briefly after its capture.

Mark first checks for a band on the bird's leg and if no band is present, he affixes a tiny numerically engraved band on the right leg.  The band number with information about the hummingbird is then reported to the Bird Banding Lab in Patuxent, Maryland, the central location for U.S.bird banding data.  These bands are invaluable to scientists who are studying the migration patterns, survivalship and health of bird populations.

The hummer is held in a stocking while it is banded to help keep it calm.  You can see how tiny the band is in the image above.

Female Rufous Hummingbirds often have a cluster of gorget feathers on their throat, unlike the Ruby-throat female which has a clear throat.  Each feather cluster is distinct and the number of orange-red feathers that appear vary considerably among individuals.  The light is striking the feathers in the image above just right to show the beautiful orange-red irridescence of the feathers.

Below, Mark is measuring the hummingbird's beak with a digital measuring instrument. Each of the measurements he takes helps to identify the sex, age and species of the bird.   

It was through telling a friend about the hummingbird that Candy learned about Bob Sargent's Hummer Study Group website and contacted Bob to report the hummingbird. Bob, in turn, encouraged her to contact Mark.  The Hummer Study Group has provided a central location for reporting the presence of western hummingbirds in the east, the most common of which, is the Rufous species.

Another view below of the throat gorget feathers.  The light striking the feather determines its color. Sometimes the feathers appear green or gray. `

Below, Mark is examining the beak with magnifying lens and a hand magnifying loop. He looks for grooving in the beak to determine the age of the bird.  Grooving indicates the beak is still maturing and the bird is in its first year after hatching.  A beak that has no grooving indicates that the bird is more mature.  This female is a mature bird with no grooving in her beak.

The gorget feathers are counted, below, and recorded, also, as a general characteristic of this individual.

Below, mark is blowing through a straw to part the feathers on the belly.  He is looking for indications of fat. Fat in the belly area indicates that the bird is feeding well, and is healthy.  He explains that most of the Rufous Hummingbirds he has banded in Tennessee have a healthy amount of body fat and are clearly finding the nutrition they need in Tennessee's winter habitat.

The recognition that a possible race of the Rufous Hummingbird species may be genetically programed to migrate to the southeastern United States is beginning to change our notion of hummingbirds and their winter hardiness.  Sargent believes, and his studies indicate, that successive generations of these Rufous hummingbirds are migrating and wintering in the eastern U.S. and that reports of their presence will increase with each season.

Presently, wintering areas seem to be in clusters of favored habitat and birders who report these wintering hummers seem to have successive winter arrivals of birds, both immature and adult. It is not certain what habitat qualities are attracting and sustaining them through the winter in Tennessee, but it is certain habitat selection is closely related to food sources.  Sap wells and insects attracted to sap wells are one known source of nutrients during cold months.  Additionally, as more and more birds are located and banded, we will begin to have a better understanding of the wintering habits of this species.

Female Rufous Hummingbirds are difficult to distinguish from the Allen's species that also have green backs and rufous in their tail feathers. Banders examine the tail feathers for the distinguishing shape and width of the feathers to confirm the identification.

Mark gives the hummer access to nectar before releasing it and she eagerly laps.  

Candy holds the bird for release.  Above and below, the hummer rests in Candy's hand until it recognizes that it is free to fly.  When it does fly, a few seconds later, it leaves with a loud chirp and wing buzzing.

We stayed to witness the hummer returning to the deck feeder for another drink. Candy has a clear view of the nectar feeder from her windows and will enjoy seeing this hummer visit her feeder as long as it remains in Tennessee.  By recording the date of the bird's arrival and the last time she sees it this winter, she will have an idea of when to begin watching for this Rufous female's return next fall.  Rufous Hummingbirds tend to return to the same wintering area year after year, as long as the habitat offers good food sources.

Next:  Another female Rufous in Johnson City, TN

Links and Resources:

Nov 11, 2013 report on Western Hummingbirds Wintering in Tennessee
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 Hummingbird 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

Johnson City Hummer is a Hardy Bird!

After high winds yesterday of up to 45 mph and an early morning low of 23°F,  the probable Rufous female hummingbird (Selasphorus rufus) at the home of Katherine Noblet, in Johnson City, has weathered the cold front just fine.

Photo credit:  Katherine Noblet

Last night Katherine reported on TN-Bird:  "My hummer is roosting in the interior of a large holly shrub that is about 6 feet from my feeder.  She is feeding about every 15 minutes and looks cold and nervous.  I think she will probably spend the night in the holly.  The shot in the holly is taken through several panes of glass and it is very low light!"

Photo credit:  Katherine Noblet

This morning Katherine sent the images below with the message:  "Alive and alert."

 

Photo credit:  Katherine Noblet

In his October presentation about wintering hummingbirds, Master hummingbird bander, Mark Armstrong, described wintering Rufous hummers that he has banded as healthy, molting and growing new feathers, having a good level of fat, and clearly fairing very well in the east Tennessee winter climate. These hummers depend on natural sources of nectar, insects, and tree sap to sustain their diet in the winter.

Photo credit:  Katherine Noblet

Rufous hummingbirds are the most common hummingbirds found in Tennessee in the fall and winter months, but you typically will not see them unless you leave a nectar feeder out.  Mark says that there are always hummingbirds that stray from the traditional migration route, but the numbers of Rufous hummingbirds found in the east does not fit a random or accidental picture.  In 2011-2012, over 500 Rufous hummingbirds were banded in Alabama and Northern Florida, and 400 in Louisianna. In east Tennessee, Mark personally banded 20 Rufous Hummingbirds in the 2012-2013 winter season. 

Bob Sargent has been banding Rufous hummingbirds in the east since the 1980's and his research suggests that a hardy strain of Rufous Hummingbirds is developing that is genetically programmed to winter in the southeast.  The Rufous species traditionally breeds in the northwest, and migrates through the southwest to winter in Mexico.

Links and Resources:

Nov 11, 2013 report on Western Hummingbirds Wintering in Tennessee
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 Hummingbird 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

Western Hummer Species Have Reached Tennessee

This beautiful male Allen's hummingbird is currently in east Tennessee!  

Photo credit:  Billie Cantwell, Knoxville, TN

On November 19th of 2011, Mark Armstrong, Knoxville, TN master bander, banded an immature male Allen's hummingbird in east Tennessee, in Russellville.  That hummer has migrated back to the same area as the beautiful mature male you see in the images above and below.  Reported by his hosts, he was captured again and released on September 23rd, 2012, confirming that he is the same individual that was present last year and in good health.      

This information can only be confirmed through banding research.  As researcher and co-founder of the Hummingbird Study Group, Bob Sargent, states:  The only way to preserve all species of birds for future generations is to know what they require for survival.  The best way to accomplish this is to learn as much about them as possible. Banding is one of the tools in that effort."  

Photo credit:  Billie Cantwell, Knoxville, TN.  Above you see the green head and back of the male Allen's hummingbird.  The bird is held by master bander, Mark Armstrong, of Knoxville, TN while being examined before release.

Allen's Hummingbirds breed in coastal California and their traditional wintering grounds are in northwestern Mexico.  Prior to 1991, an Allen's had never been documented in the five eastern states of Alabama, Georgia, Florida, Tennessee or Mississippi, according to Sargent, and the first documented case occurred in Alabama in 1991. The first recorded Allen's in TN was banded by Bob and Martha Sargent in the Chattanooga area in 1993.  Since that time, eastern residents have been encouraged to leave at least one feeder out after November 15th.  It is now known that these western migrants, the most common of which is the Rufous Hummingbird, can arrive as early as July and August, though they are more difficult to identify midst a steady influx of migrating ruby-throats. 

Photo credit:  Wally Manspeaker, Russellville, TN.  Above and below, the beautiful mature Allen's hummingbird currently visiting east Tennessee feeders at a home near Russellville, TN.

Wintering western hummingbirds do not rely on human-provided nectar sources, but find their own sources of nectar and protein in nature.  The primary reason people are encouraged to leave feeders out in the winter is so we can better document these birds and learn about their survival habits.

Photo credit:  Wally Manspeaker, Russellville, TN

The following report was provided to the Tennessee List-serve on November 19th, 2011 by Mark Armstrong:

"On November 19 I banded a young male Allen's hummingbird at a home near Russellville, Hamblen Co. [TN]....It has been a banner year for wintering hummingbirds this year.  In the eastern TN area I cover I have banded 5 Rufous hummingbirds, the Allen's, a late Ruby-throat and I had a return Rufous that I banded last year.  The Rufous that I've banded have been in Johnson City, south Knoxville, and 3 in Tellico Village, Loudon Co....I'm not the only one seeing a lot of hummingbirds.  Other banders [in] the eastern US are getting record numbers of Rufous as well as Calliope, Broad-tailed, Allen's and Anna's.  If anyone has thought about leaving a feeder out this would be the year to try it."

Clearly, 2012 promises to be a busy year also!

Photo credit:  Billie Cantwell.  Above, Mark Armstrong, in Russellville, TN.  Beside him is the trap apparatus that is used to capture hummingbirds for banding.  The trap door is closed via a connected line after the hummer enters to feed.

Not only do we have this Allen's Hummingbird present in the eastern portion of our state, we also have Rufous Hummingbirds currently being reported in upper east Tennessee and in the Chattanooga area.  These birds are often first identified as immature birds, but as in the case of this Allen's, they frequently return to the same areas while migrating and to the same wintering grounds year after year.

With each season that western breeding hummingbirds are documented in the eastern United States, we learn more about the nature of the species and their migration patterns.  If you live in the east, keep at least one feeder out during fall and winter and check the reference link below for information about who to contact to report a wintering hummingbird in your state.

Links and Resources:

Previous blog posts on western hummingbirds in the east:  wintering hummingbirds
More on hummingbird banding:  hummingbird banding
Sketches of an incubating Allen's Hummingbird

Who to contact if you have a wintering hummingbird
Hummingbird Study Group
Allen's Hummingbird
Rufous Hummingbird
Wintering hummingbirds in TN:  Second record of Allen's in TN, The Migrant 2001, The Migrant 1998:  five species of wintering hummingbirds

Next:  back to Alaska!