THE AMERICAN DIPPER
Article and Photos by
Jeannie Marcure
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One of my favorite things
about bird watching is that it can be done almost
anywhere and can easily be combined with other pastimes.
If you’re quietly aware of the natural world around you,
great birding moments often happen when you least expect
them. One such serendipitous moment occurred for me last
summer as my husband and I took our annual hike to
Virginia Falls in Glacier Park on July 8, a good 2-3
weeks later than usual due to the late opening of Logan
Pass. Near the bridge below Virginia Falls, a small dark
bird flew in and landed on a rock across the stream.
After a quick check with the binoculars and because of
the bobbing motion as it perched there, I recognized
this bird as an American Dipper. Further inspection told
me that this was not an adult but rather a newly fledged
juvenile. Shortly after its somewhat uncertain landing,
the small bird began to call loudly, and almost
immediately an adult Dipper appeared with a morsel which
she promptly offered to the juvenile. This continued for
20 to 30 minutes with the juvenile never entering the
water and the adult returning with food every few
minutes. Although I’ve often seen Dippers in this area,
this was my first chance to observe a juvenile and its
interaction with its parents, so I was motivated to
learn more about these unusual little birds.
With a uniformly slate-gray color, long legs, a somewhat
stocky body and short tail, the Dipper (sometimes called
the Water Ouzel) is 7- 8 inches long and weighs just 1.5
to 2.5 ounces. The sexes are similar but the male is
larger. Its most identifiable feature is its constant
bobbing as it perches on streamside rocks.
Inquiry at
www.scienceperspectives.com
told me that although Dippers are aquatic birds, they
are not waterfowl but rather songbirds, and their
closest relatives include chickadees, robins and wrens.
Despite this close relationship with songbirds, Dippers
spend their entire lives in or near the water of clear
mountain streams and feed entirely on aquatic life, with
their favorite foods including mosquito larvae, caddis
fly larvae and small fish. They are often seen walking
along the bottoms of fast moving streams probing for
food. They can also “fly” underwater, moving upstream in
the rapid water by using their wings for propulsion.
Interestingly, they can also fly straight into the air
from underwater. When moving to a new location, Dippers
fly just above the water, even when the watercourse
curves and a land route would be shorter. Because their
globe-shaped nests are made of moss and mud and placed
streamside or perhaps even behind a waterfall, they are
hard to spot unless you’re lucky enough to see the bird
entering or leaving. Both sexes sing and defend a linear
mile of streamside territory. Unlike most songbirds,
Dippers do not migrate to warmer climates in the winter
but rather stay in the breeding territory as long as
there is running water. If the stream does freeze, they
move downstream just far enough to find running water
again. Dippers are regularly found on the Kalispell and
Bigfork Christmas Bird Counts.
Dippers possess several unique adaptations that allow
them to live in the sometimes harsh environment of
mountain streams. Imagine spending most of your life
with your feet in that cold water! Dippers have a thick
undercoat of down that protects them from the chilling
temperatures of the mountain streams that they call
home. They also use a preen gland which secretes oil
that is used to waterproof their feathers. This gland on
the Dipper is ten times larger that of any other
songbird. David Attenborough, in his video series The
Life of Birds, says that Dippers are so well-oiled that
the resulting buoyancy causes them to have trouble
staying submerged and they can only manage 15 seconds or
so at a time. A low metabolic rate and extra
oxygen-carrying capacity in its blood also help the
Dipper. A flap that closes over the nostrils under water
works much like nose plugs used by human swimmers. In
addition, a highly developed third eyelid acts like a
windshield wiper to help clear the eyes after diving.
You can observe this eyelid as the white flash that you
see every time a Dipper blinks.
Unlike most other songbirds, but similar to ducks, the
American Dipper molts its wing and tail feathers all at
once in late summer. It is flightless during this time.
Next time you hike or fish along one of our beautiful
mountain streams, watch closely for a small dark bird
flying low over the water. Listen for the buzzing trill
and perhaps you too will be lucky enough to watch an
American Dipper as it walks under the water searching
for a meal. |