Saturday, October 19, 2013

Hummingbird Festival Featured on Tennessee Wild Side

The Wonder of Hummingbirds Festival is featured on Tennessee Wild Side, an Emmy Award winning television production produced by the Renaissance Center.  Enjoy this enchanting program about the festival, its activities and the main star, hummingbirds!

The festival is co-sponsored by the Knoxville Chapter of the Tennessee Ornithological Society and Ijams Nature Center.  The 2014 festival will be held on Saturday, August 23rd.  Mark your calendar!

KTOS is a non-profit organization that promotes the enjoyment, scientific study and conservation of birds. Ijams Nature Center seeks to increase knowledge, understanding and appreciation of the natural world by providing quality environmental education and nature related experiences.

Links and resources:
More about the festival:  Wonder of Hummingbirds Festival
More about hummingbird banding and hummingbirds on this blog
Mark Armstrong
Ruby-throated hummingbirds
Knoxville Chapter of the Tennessee Ornithological Society
Tennessee Wild Side
Ijams Nature Center

Sunday, October 13, 2013

Hummingbird Migration--Leave a Winter Feeder Out!

Ruby-throated hummingbird migration through Tennessee is winding down.  Most people assume all hummers are gone.  It is true that the majority of migrating hummers are well south of Tennessee now, but there are some late individuals coming through.  
Last night I had two in the evening, one perched next to the pineapple sage, nectaring and resting, nectaring and resting, with no feeder visits.  The second was perched high on a limb and made a brief visit to the flowers before being chased away by the first bird.
This morning I also had two ruby-throats visiting the pineapple sage. Both of these birds also visited the feeders briefly and were seen between 7:30 and 8:30 a.m.  In the days previous, the hummers I have observed have only been nectaring the salvia, both the black and blue variety and the pineapple sage.  
I have had good luck with the pineapple sage I planted this spring and it is blooming profusely right now. The salvia family seems to love the cooler season and the hummingbirds love the salvia. Below, a hummer visiting the pineapple sage yesterday, Oct 12th.
Yesterday, I also went to a presentation given by Mark Armstrong, a Master Bander of hummingbirds and the person in our area to contact when we have a wintering hummingbird. Leaving a feeder out is a good thing to do if you live in the southeast. It is not that the hummingbirds that winter in our area need our feeders, but having a feeder out enables us to see them more readily and learn about these birds.
Above you see an immature Rufous Hummingbird that was captured and banded in January of 2011 in west Knoxville.  This hummingbird returned to the same area and was recaptured in December of 2012 as a healthy mature male.  Below, a slide presented by Mark in his presentation at Wild Birds Unlimited in Knoxville with historical information about wintering Rufous Hummingbirds in the southeast.
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.
Mark explained that there are always hummingbirds that deviate from the expected migration route but the increase in Rufous hummingbirds doesn't fit with random events.  Hummers will travel to areas where the climate and food is beneficial to their survival and some are clearly drifting east and returning on a regular basis. Mark reported that all of the Rufous Hummingbirds he has banded are healthy, molting and growing new feathers, have a good level of fat, and clearly are 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.
Allen's Hummingbird that wintered in Russellville, TN in 2011 and 2012. Photo credit: Billie Cantwell.

There are several species of hummingbirds that have been recorded in Tennessee in addition to the Rufous: Black-chinned Hummingbird, Allen's Hummingbird, Anna's Hummingbird, Calliope Hummingbird, Broad-tailed Hummingbird, and Green Violetear. Unlike the Rufous, other hummingbirds are rare visitors and are not known to return for consecutive years. There are exceptions, such as the Allen's hummer that returned for a second season last year.  

There are many things that remain unknown about hummingbird migration.  Leaving a feeder out for wintering birds allows us to see the hummer and possibly band it so that biologists can learn more about hummingbird migration patterns, changes in these patterns, and about wintering species in the east.

If you live in the east and have a hummingbird visiting a feeder in your yard after November 15th report your observations. For information about who to contact if you have a wintering hummingbird, click this link.
Incubating female Allen's hummingbird sketched from a live webcam by Vickie Henderson.  The Allen's species breeds in coastal California and traditionally winters in northwest Mexico.

Links and Resources:

Mark Armstrong, Master Bander of hummingbirds and songbirds, Avian Curator at the Knoxville Zoo, and past president of the Knoxville Chapter of the Tennessee Ornithological Society

Blog posts on hummers wintering in Tennessee:
Allen's Hummingbird in east Russellville, TN
Calliope Hummingbird wintering in Nashville, TN
Rufous Hummingbird and Rufous Hummer in Knoxville
Migration Surprises
Hummingbird Study Group

Friday, October 4, 2013

Ruby-throat Combat is Serious Business

These are the final days of Ruby-throat migration.  The last of the juveniles and late female breeders will be gone from my area in east Tennessee in a little over a week, as they move southward and eventually arrive in their wintering areas in southern Mexico and Central America.
We often attribute Ruby-throated aggression to high testosterone levels during breeding season, but clearly some of that aggression is pure Ruby-throat personality. In fact, this young bird makes it appear they are born with this aggression and have a timing-mechanism that stimulates its expression by the time they migrate.
On most mornings recently, the hummers drink hurriedly and move on to feed on insects, paying little attention to each other, sometimes even settling on the same feeder to drink.  This morning was different, however, with two juveniles keeping up a relentless dispute over territory that lasted at least fifteen minutes, if not longer.  
Their combat included face to face flight moving high into the air and dropping low into foliage.  Once I saw them land on twigs in close proximity, each seeming to expect the other to leave before they finally tangled in defiance.  Sometimes they directed high speed dives at each other and many times I heard wing buzzing and in-flight "splats" like those you hear at the feeders, but neither would give up dominance.
Eventually, they ended up on the ground. Having seen this before, I expected a brief skirmish with both birds eager to return to the air.  What I saw surprised me.
One bird succeeded in pinning the other to the ground and seemed quite content to keep him there. His posture as he held the bird down gave every indication of victory, with wings spread, neck stretched, looking slowly from side-to-side, as if proud, giving the appearance of dominance posturing.  You can see the top bird's foot in the above image and some of the others. He appears to have the bird pinned by the shoulder and right wing.  It is also likely that his other foot is on the bird's beak since the pinned bird did not raise his head while on the ground.
While holding the downed bird firmly in place, the top hummer proceeded to alternately lift his feet up and down in a "kneading" pattern, his body rocking with the movement. The pace would be similar to the steady rhythm of kneading dough.  A hummer's version of stomping?  This movement and pin-down lasted approximately a full minute and I became concerned that the downed bird might not survive.
As you scroll through the images below, you will see that the bird on the bottom is trying to move, curving his back to struggle free and moving his left wing.

I can't be sure if the top bird was ready to leave and simply lifted off, or if the bird on the bottom wiggled free.  Since I couldn't see the bottom bird clearly while watching, after the top bird flew, I walked over to look at the ground and fully expected to see a dead hummingbird.  Much to my relief, he had flown too.

It is pretty amazing how quickly a hummingbird's life changes from timid fledgling to sword-carrying militant. Clearly this young male is wired for survival!

More about hummingbird aggression 
Bob Sargent on Ruby-throated Hummingbirds
Hummingbird Study Group
Other posts on Hummingbird migration
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For the Love of It...

...the sage sees heaven reflected in Nature as in a mirror, and he pursues this Art, not for the sake of gold or silver, but for the love of the knowledge which it reveals.
Sendivogius (1750)

Your Uncapped Creativity...

Your Uncapped Creativity...
"There is a vitality, a life force, an energy, a quickening that is translated through you into action; and because there is only one of you in all time, this expression is unique. If you block it, it will never exist through any other medium and it will be lost. The world will not have it. You must keep that channel open. It is not for you to determine how good it is, nor how valuable. Nor how it compares with other expressions. It is for you to keep it yours, clearly and directly." ----the great dancer, Martha Graham