[mou] Hedbom Road wonders 1-5-07

[Alt, Mark]

The wonders of Hedbom Road has left me studying three hours of video =
shot there last Friday, learning more about these birds, reobserving =
what I filmed. I was in the constant company of a total of six =
Black-backed woodpeckers (2 female s, 4 males) and a male American =
Three-toed Woodpecker. The woodpeckers moved around and were at times =
very close to us. In editing and studying the footage, I was able to =
study behavioral and physical attributes of these birds and made some =
anecdotal observations.=20
The BNA states that Black-backed and American Three-toed Woodpeckers are =
perhaps the most adapted of the Picoides woodpecker family for =
excavating boring insects... I thought they scaled off bark for the most =
part. It turns out that these birds' three-toed anatomy allows the back =
part of the foot to rise up prior to delivering a blow with its bill. I =
observed them just barely holding on with the tips of their claws, like =
a climber on a finger-hold on a sheer rock face. When excavating, the =
back of the foot (is it a heel?) lifts up noticeably, the bird's head =
lifts up and back as it stretches its body and then the bill strikes =
downward, usually in a series of 2-5 blows.  This allows the body and =
legs to accelerate to put the weight of the bird into the blow. These =
two species also are the most adapted to cushion the blow within the =
skull structure. It flakes and excavates constantly, flaking off a piece =
of bark that looks for the entire world like a Wheaties flake; cocks its =
head, and darts its slender pale tongue into the dark pin holes that =
indicate beetle larvae beneath. The tongue serves to spear the larvae, =
yet it extracts them so quickly, it is hard to capture, even on film. I =
guess 80% of the larvae it encounters on these larches it is feeding on =
are eastern larch beetle larvae, less than =BC inch in length, small =
white grubs, but on occasion it gets into bigger prey, where it then =
excavates deeper holes, conical in shape, from where it extracts larvae =
that are =BE inches long and fatter, big white grubs, sometimes more =
than one from a hole..  I do not know what species these might be, but =
there are many beetles that are predators on the eastern larch beetle, =
so it may well be one of these. Some of the trees have larvae so =
abundant that the exposed red bark shows a black stippling from all of =
the larval holes. It appears the woodpecker can check three or four =
holes in a split second interval. This is the reason for these birds =
having such an unsyncopated rhythm when feeding, alternating between the =
use of the bill and the use of its tongue. The birds seem preoccupied =
with their work at hand that are approachable if you are quiet and make =
no sudden moves.=20
We had several Black-backeds and a Three-toed in one small area for over =
an hour, yet the only vocal we got occurred when a female Black-backed =
suddenly appeared on the tree next to the male Black-backed. The male =
assumed a hunched-over position, spread and vibrated his wings, lowered =
his head, and emitted a loud call, their "rattle snarl call" which is =
very loud, sharp and slightly descending, very unlike any call I have =
ever heard from a Minnesota Woodpecker. The female calmly continued =
feeding, and the male then proceeded to climb his tree in an animated =
fashion, flicking his wings open and shut. He seemed very agitated for =
about 10 seconds, and then resumed feeding, seeming to no longer notice =
the female.
The Black-backed Woodpeckers seemed to pay little attention to the male =
American Three-toed, only landing on the same tree twice in the time we =
observed. On both occasions, the Three-toed promptly moved to another =
tree. We noticed no great attention being paid to the red squirrels =
calling, but on two occasions as I watched the Three-toeds, when Red =
Crossbills are heard overhead, the woodpecker stopped, craned its neck =
to fix one eye skyward, paused until the birds were no longer heard, =
then resumed it  feeding. The birds were mostly visible feeding from 15 =
feet or lower, for some time the birds' tails rested on snow as they fed =
at the very bottom of trees. Both species were observed feeding above 40 =
feet in tall trees, but this was the exception.=20
I had read that these birds do not typically roost in trees, so I stayed =
near the Three-toed until 5:00 PM, and this means it was dark out, =
barely enough light to see to walk out. The bird flew out of sight. =
Bummer, yet we were rewarded with a hunting Great Gray Owl right along =
Hedbom Road; it was totally dark, so I got to check out my friend's =
night vision scope and watch the Great Gray take mice in the woodlands. =
Red-backed voles? White-footed Mice? Errant Meadow Voles? The owl's eyes =
glowed like an Ewok in the coke-bottle-bottom-green light that revealed =
it.  A great day with great birds in a truly wonderful spot. Good =
Birding.

Mark Alt
Brooklyn Center, MN