Subject: [Tweeters] Hoodies & Woodies Fledging (long)
Date: May 12 17:21:34 2007
From: Lee Rentz - lee at leerentz.com


This morning at 8:35 a.m., a mixed brood of five Hooded Merganser and
four Wood Duck chicks leaped out of our nest box and joined their
"mother," a Hooded Merganser, on the surface of Fawn Lake. Then they
swam away in a tight cluster across the lake, evading the River Otter
that swam by a half hour earlier.

We live on the shore of Fawn Lake, near Shelton in Mason County.
Nearly ten years ago we began maintaining several Wood Duck nest
boxes on a tall, but scraggly, Bigleaf Maple at the water's edge in
front of our house. We have had Hooded Mergansers nesting in the box
each year, but only once did I see a mother swimming with her young
across the lake and away from the nest box. In the last several
years Wood Ducks have begun coming to the nest boxes, creating some
competition for nest box space with the Hooded Mergansers. [Wood
Duck pairs also fly up to our deck and feed on sunflower seeds, but
that's another story.] We believe we have added to the population of
Wood Ducks and Hooded Mergansers on the lake, with up to ten of each
species hanging around the vicinity much of the winter.

Each winter we have Hooded Merganser males and females courting on
the lake. Toward the end of winter, they pair off and begin mating.

This year we decided to try to see inside the box and record the
nesting story, so in early March we installed a wireless infrared
security camera inside the nest box. The camera is about 60 feet
from the house, and it requires a power cord ("wireless" refers to
the transmitter that attaches to a television). We had heard about
nest box cameras several years ago at a Portland Audubon Society
event, but most of this type of activity is done in England, as you
will see if you Google something like "nest box camera." The
English, like those of us who live in the woods on the Olympic
Peninsula, are known for their eccentricities!

Every year I prepare the nest boxes by climbing a tall ladder and
removing the old wood chips and eggshells from each box, then
installing a fresh layer of pine chips (obtained from a store that
offers pet supplies). I did this on 10 March. I also installed the
video camera at this point and we began watching the nest box on our
television. In fact, since then the television has been tuned to our
"next box channel" virtually all the time.

Over the next several weeks, we watched as the nest box was explored
by a Northern Flying Squirrel one night, and a Starling on another
occasion. But mostly we observed female Wood Ducks and Hooded
Mergansers entering the box and staying about ten minutes each morning
?long enough to lay an egg. But we couldn't count the eggs that were
accumulating because the females would carefully cover the eggs with
wood chips after laying.

On 7 April, two different Wood Duck females entered the box in short
succession, and we believe each laid an egg. Then, the same morning,
a female Hooded Merganser entered the box and settled in to incubate
the accumulated eggs.

At this point the Hooded Merganser began plucking out down feathers
and tucking them under her body. As she added the downy feathers,
the feathers and wood chips became mixed together into a matrix that
looked and moved much like a soft mattress. Humans must have gotten
the idea for feather beds directly from ducks!

As the female incubated, the eggs were hidden from our view and it
was nearly impossible to count them, though sometimes we would get a
glimpse of about half a dozen at a time. The Hooded Merganser left
the box roughly three times per day for a break, each time carefully
covering up the eggs by pulling feathers and wood chips up and over
them with her beak. When she left, she flew quickly and directly
across the lake, rather than lingering in the vicinity of the nest
box, presumably to avoid calling attention to the nest area. She
normally stayed away for about an hour, though sometimes as long as
two hours. Occasionally, while she was gone, a female Wood Duck
would enter the nest box, uncover the eggs, and incubate them for
fifteen or twenty minutes. Then she would cover them up and leave
the box before the Hooded Merganser returned.

Whenever the Hooded Merganser returned from a break, she sat atop the
nest and used her webbed feet to uncover the eggs?paddling with them
one way, then turning around and pushing the feathers and chips away
in another direction, and so on until all the eggs were uncovered
(though not seen by our camera which looked down from above). Then
the merganser would wiggle her body gently and repeatedly to settle
in, covering all the eggs with her warm and downy body. With her
bill she would pull the feather/chip matrix up over the edges of her
body to add additional insulation.

On at least four occasions, a female Wood Duck entered the box while
the Hooded Merganser was inside?and each time a big fight ensued.
Feathers flew, bills jabbed, and necks were grabbed by bills. Each
time, the Hooded Merganser triumphed and expelled the intruder, then
quickly settled down to incubate again. There was also a time when a
rival Hooded Merganser entered the box and the two ladies fought
hard, with the resident winning.

As the days accumulated, we began looking forward to seeing the eggs
hatch, and started staying home on weekends so that we wouldn't miss
the event. After reading that Wood Ducks will "dump" eggs in boxes
containing other species?to the extent that there could be too many
eggs for successful incubation, leading to nest abandonment?I began
actively chasing away Wood Ducks whenever they tried to enter the
video nest box. Yes, I'm playing God or being a good steward of nature
?depending on how you choose to look at it.

On 7 and 8 May, the temperature outside spiked to over 70 degrees F,
and the Hooded Merganser inside began panting?keeping her bill open
for long periods to try and cool herself. We had never observed this
before, and were worried about her health, but apparently many
species of birds pant when under heat stress.

Finally, on 11 May, at about 8:30 am and after 34 days of incubation,
I noticed some dark spots on the eggs, then cracks, then wet young
chicks. Over the next four hours or so, more and more chicks began
appearing. They dried out quickly, and mother tried to tuck them
under her. The mother picked up the empty eggshells and violently
shook them with her bill?we're not sure why?but the shells emerged
from the shaking more fragmented and flattened.

As the day went by, the chicks became more and more rambunctious,
with some of them leaping up the sides of the nest box. Then all
would disappear under mother for a time, then cutely emerge from
under her wings and tail. Sometimes they would be crawling all
around and over her. But she was a patient mother. Several times
she left the box for a short time, leaving behind a dark and feathery
pile of chicks. When she returned for the night all the birds went
to sleep, or as much sleep as a group of squirmy youngsters can get.

This morning, 12 May, the female left the box for a time, then
returned. Next she went up to the nest box opening and looked out
for several minutes?presumably checking that the coast was clear.
She then went back down into the box, then fairly quickly left the
box again, flying down to the lake surface below the box. The young
quickly followed?within a minute all nine had climbed up to the
opening and plummeted down to the lake. We've never seen them
leaping out before, and it was really exciting to twice see them take
the plunge two at a time. So then we had an empty nest box, with
five unopened eggs left behind. We don't know what kind of signal
the mother used to get the young to follow, but presumably it was
something she said.

The mother gathered her chicks together and they immediately began
swimming in a tight cluster across the lake. And if past experience
is a guide, we will never again see them as a group.

We wonder, of course, how the Hooded Merganser will fare as foster
mother to four baby Wood Ducks.

And that is the end of the story for 2007. We will post video
segments of the experience on YouTube at some point, but that will
involve editing hours of DV tape in iMovie.

In case anyone is interested in putting a camera inside a nest box,
we ordered ours through ebay from Duncans Online; it was called a
Wireless Waterproof/Day/Night Vision Color CCD SpyCam. For use
inside a bird box, they suggested covering about 70% of the infrared
lights on the camera with tape so the viewing area wouldn't be
overexposed. That worked well. The camera itself was shipped
directly from China and took about six weeks to arrive. It worked
flawlessly from day one. We used a digital video camera pointed at
the television to do our recording.

Lee & Karen Rentz
Shelton, WA
lee at leerentz.com