[birding] nest updates

Nancy Stotz nstotznew at gmail.com
Sat Mar 17 19:32:48 PDT 2018


Just wanted to give an update on a couple of active nests in NW Corvallis
that I reported to the list previously.

The Anna's Hummingbird nest I first noticed across the street from our
house on March 3 continues to be active. The email I sent out that day
wasn't entirely accurate. Although at the time I sent it, I had seen no
indication that the female was feeding young and assumed she was still just
incubating eggs, in the early afternoon that day, I saw the female feed
young in the nest, and she then settled into the nest to brood. After
seeing her get settled, I grabbed a notebook and settled in myself, for a
one-hour nest observation. The brooding female left the nest 8 times during
the hour (absences ranging from about 15 seconds to 2 minutes); upon
returning to the nest those 8 times, she almost always settled in
immediately to brood. Only once did she feed the young upon her return (50
minutes after the first time I observed a feeding). I did another one-hour
observation on March 4, and during that hour, the female left the nest 10
times (15 sec to 4 minute absences), feeding the young twice (28 minutes
apart) before settling in to brood. On those days, the beaks of the young
were not visible above the rim of the nest, which is directly across from
my scope-aided, living-room perch (essentially at eye level). The first day
I was able to see nestling beaks sticking up above the rim of the nest was
March 7; there were clearly 2 young in the nest.

We were then out of town for several days, and upon returning, we checked
to make sure the nest was still active. When the female came to feed, we
could tell there were still 2 young in the nest, and even when they are
resting, now their backs are visible above the rim of the nest. Yesterday,
I happened to be looking through the scope when the female came to feed,
and then she moved from the rim of the nest where she perches to feed, and
seemed to try to settle in to brood. She kept wiggling and poking into the
nest, and then flew away. Though I am fearful of being accused of
anthropomorphism, it sure looked like she just couldn't get comfortable on
her nestful of young, and just gave up.

Today was the first day I had a chance to do a one-hour observation since
getting back. During the hour, the female never brooded, but visited the
nest 3 times to feed the young. The nestling's beaks are still quite short:
bill length still appears to be a little less than the depth of their
heads. They still have plenty of downy feathers visible on their backs, but
their flight feathers are starting to develop. I could see the flight
feathers on their wings when they stretched, and especially, when one of
the nestlings did some practice wing flaps.  When I watched the one flap
its wings I was amazed to see that the flap speed seemed to be the same as
the adult's hovering flight. The wing shape and details I was able to pick
out were like that somewhat blurry optical delusion of the adult wing shape
that our slow-working minds create when we watch an adult hummer hovering
at a feeder.  While it was doing the high-speed practice flap in the nest, I
could make out the shape of the body of the wing, the bare shafts of the
row of developing flight feathers, and the just opening tips of the feather
blades at the end of the feather shafts.

One other quick update. On Christmas Day, I sent an email about a
Red-tailed Hawk nest under construction in our neighborhood. Both my
schedule and the difficulty of finding a good place to observe this nest
without freaking out the neighbors has kept me from keeping a close eye on
this nest, but I had assumed I had missed the bulk of the activity there
since it has been almost three months since I saw twigs being carried into
the nest. But, on March 14, I happened to be walking by when an adult flew
into the nest tree with a prey item in its talons. I wasn't in the right
spot to actually see the nest, but given where I lost sight of the bird, my
best guess is that it was delivering the prey to the nest.

Nancy Stotz


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