Posts tagged “chickadee

Black-Capped Chickadee Beak Deformity

Chickadee with beak deformityI made this little animation to show how this poor chickadee was being bothered by its beak deformity.  Every so often it would rub its beak against the edge of the bird feeder like this.  It appeared relatively healthy so it must have been able to eat satisfactorily, but apparently this deformity causes it to be obsessive about trying to scrape off the excess beak.

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Black-Capped Chickadee Beak Deformity

First seen in the winter of 1991-92, Black-Capped Chickadee beak deformities are now quite common, according to the Alaska Science Center.  To date, there have been over 2100 reports of chickadee beak deformities in Alaska, and only 31 outside of Alaska.  In the photo above, you can see that the chickadee’s beak is at least twice as long as it should be, and the bottom part is crossed and curved up.

The Northwestern Crow suffers from this malady as well, with an astounding 17% of adult birds in Alaska exhibiting some level of beak deformity (as opposed to 6-10% of adult Black-Capped Chickadees).

Other birds with reported beak deformities are the Black-Billed Magpie, Red-Breasted Nuthatch, and Stellar’s Jay – although none of these reports come anywhere close to the high number of sightings of the Black-Capped Chickadee.  Other species of chickadee have been seen with the problem too but they number under 10 total.  Whatever the source of the problem, Black-Caps are especially vulnerable to it.

This map (from alaska.usgs.gov) shows locations of Black-Capped Chickadee beak deformity sightings.  At first they were centered around Bristol Bay and the Mat-Su Valley but they soon spread to Fairbanks (where I live) and elsewhere.  There are plenty of sightings in remote locations so the problem does not exist only in populated areas.

The poor creatures with deformed beaks often have a very hard time eating – it’s actually kind of amazing that they do get by at all.  The one on the right kept rubbing the elongated portion of its beak on the wood of our feeder, as if attempting to rub it off.  No doubt feeders and even garbage help to keep them alive but mortality is undoubtedly higher among them.  Normal preening is greatly disrupted.  And though many of them do find a mate and breed, fewer eggs hatch to a pair in which the female is deformed and fewer young survive when the male is deformed.

Possible causes are contaminants, nutritional deficiencies, disease, genetic abnormalities and parasites.  Read more about those at http://alaska.usgs.gov/science/biology/landbirds/beak_deformity/causes.html

On the left is an example of a normal beak.

 


Running out of suet, after a long cold winter…


A Merlin Hits our Window

I was only a few feet from the window when this Merlin flew into it with a jarring thud.  As you an see, he is quite stunned in the first photo.  Poor guy.  He’s about a foot long, a pretty small falcon.  At first I thought he was an American Kestrel since I had never seen a Merlin.  Didn’t even know they were in interior Alaska.

This one is either a female or a juvenile (or both).  No doubt he was drawn to the multitudes of Juncos and Chickadees at our feeder (actually in the summer we don’t use a feeder but just put sunflower seed hearts on the deck railing so they don’t gorge themselves).  So this little guy was hunting our lovely resident birds, hmm.

Turns out the Taiga Merlin is quite common in Alaska and Canada and their populations are stable.  There is also the Prairie Merlin that is increasing in number – apparently it’s getting quite used to city life where it overwinters, feeding on rodents and birds.  The Black Merlin lives in the Pacific Northwest (it’s numbers are also stable).  (There is also a Eurasian Merlin that is a separate species, having ceased to interbreed with the North American Merlin at least a million years ago, and their numbers are less certain.)

Nearly all of Alaska’s Merlins migrate.  They may winter in North America or South America, often along coastlines feeding on shorebirds.  No vegetarian meals for this carnivore – the smallest thing it eats are perhaps dragonflies plucked from the air as it’s soaring over the trees during migration.

The Merlin is a tough little falcon, it will attack anything and teams up with its mate to cooperatively hunt.  It even takes birds larger than itself, like pigeons; it is known as a “pigeon hawk” in many areas.

Instead of tedious nest-building Merlins use old crow or magpie nests, or they make due with a cliff outcropping or scrape in the gravel.  The female lays 3 to 6 eggs and sits on them for a month, both feed the little ones for another month, and then the fledglings continue to beg for awhile longer.

Here is a photo of the powder he left on the window.  He really hit it hard.  Many birds have a light dusting of powder all throughout their feathers.  It comes from down feathers that grow and disintegrate.  Since feathers are made of keratin that’s what the dust is made of, and it actually causes allergies in some people who keep birds indoors.  For the bird, it’s crucial to waterproofing and cleaning.

My husband and I have tried various things to prevent birds from hitting our windows, like hanging shiny objects over them, but I haven’t found anything yet that is attractive and easy to clean around (and effective for that matter).

The Merlin eventually flew up to a railing, then off into the woods.  I hope he remembers how painful our windows are so he doesn’t fly into them again.  More than just his ego was bruised I’m sure.