Tweeters,

For those interested in raptor nesting behavior:

I inadvertently discovered a red-tail hawk nest while visiting Tacoma on
the 9th.

I stopped to look over the Puyallup river, coming from Dash Point State
Park on Marine Drive about 1/3 mile before (west) of the intersection
with highway 509 (which cuts straight across the port of Tacoma). There
is a decent pullout, with a series of posts with a cable strung through
them to keep people from falling off the short embankment over the river.

When I opened the car door I heard a jay distress call, and then the sharp
kerrr of a red-tail hawk. In a half-dead madrone tree, near the top of the
bluff across the road (Marine Drive) from the river was the nest.

There is one good-sized nestling, still downy but 1/3 to 3/4 as large as
an adult, visible from the ground. The attendant adult was very displeased
with my viewing the both of them with binoculars. I proceeded to check out
13 adult Canada geese, 8 male mallards, and several non-breeding gulls on
the river mudflats. I turned back to look at the nestling again; the adult
flew up several feet and took a stoop straight at me! What a powerful
sight it is. Obviously I was harrasing this bird (the nestling was quite
non-plussed), so I went directly to the car and paused to watch the adult
pull out of the stoop several hundred feet from me, gain altitude, and
give me a much more serious encouragement to leave; this stoop pulled out
about 100' away, and I left.

Of course I had to bring my wife by to see this later in the afternoon. We
saw an adult (another one was soaring quite high, about a 1/2 mile from
the nest) bring in the hindquarters of a gray downy nestling, with black
webbed feet, about the size of a small duck (I suspect this was a
gosling). We didn't hang around for more than a couple of "kerrr"s so as
to not be too big a bother.

One more note, when I first saw the nest the adult was flying in with a
Douglas-fir branch-tip, with light green needles (new growth) on it. It
stopped by the nest, and then flew out and dropped either the same branch
(it was kerrring at me by then, so I could very well have modified its
intended actions) or another one it picked up in the nest. According to the
Birder's Handbook, many birds use this as a possible means of pest control
in the nest.

Parting (to get to work, yuck) with a question: do red-tail hawks usually
have just one nestling survive to fledging? I read about "obligate
siblicide" in the Birder's Handbook - which indicates that some raptors
appear to have the nesting strategy of only the oldest nestling surviving,
and the younger one(s) essentially *always* perishing?


Michael Patrick
mpatrick at eldec.com
(206)743-8204