Unfortunately one of the two Osprey chicks at the nest camera site
north of Jetty Island was lost last Tuesday (7/20/04). The older
chick had been establishing dominance over the younger chick since
about a week and a half old and had often been preventing the
younger chick from feeding. By Tuesday there appeared to be over
a week's difference in size of the two chicks, even though they
were actually only a day apart in age. Tuesday morning the runt
was weak and listless and having difficulty with balance and about
1 p.m. while trying to sit up it rolled over backwards off the
edge of the nest to the mudflats about 20 feet below. The tide
would be out for a couple more hours, so we decided to try to
retrieve the chick and with considerable difficulty were able to
slog across the mudflats to the base of the piling where we found
the chick still alive. Unfortunately it had suffered breaks in
both wings and possibly other injuries and died later that evening
in the care of a rehabber.

I have been recording several hours of video tape of the nest
activities about every other day and most of Tuesday's events were
recorded. The older sibling did not push or drive the runt out of
the nest but it had been attacking it by pecking at the back of
it's head and neck often during the preceding days. Interestingly
enough, the attacks were often not during feedings but at times
between feedings and were interspersed with periods of normal
non-aggressive sibling behavior in the nest. The runt learned to
go into a submissive, head-down stationary position when the older
chick threatened. The parents made no attempt to interfere with
the aggression. On one occasion the female placed herself between
the two in order to feed the runt but that did not occur often
enough to prevent it from becoming increasingly weak and
dehydrated.

All this is normal where runting of the youngest occurs with
Osprey, however it is the first time I have witnessed the sibling
aggression at Everett, although I am sure it happens at various
nests. We were a little surprised to see it play out to the end
as the male has been returning what seems like plenty of fish,
usually about one every two hours during the daytime when we are
watching. I am seeing similar aggression at two nests in the
Duwamish River area nests that I am also watching.

The remaining chick is doing fine and will probably fledge around
August 6. We have found that most of the fish being returned to
the nest are either Starry Flounder or Pacific Staghorn Sculpin
which are making up the bulk of the diet. On one occasion there
was an eel-like fish returned by the male which was very
interesting to watch as it writhed around in the nest. Other
species include Shiner Perch, Plainfin Midshipman, and a couple
salmonids.

The nest video monitor is located in Discovery Hut on Jetty
Island, Everett, WA. The Parks Department operates a free
passenger ferry to and from the island Wed-Sun from the 10th St.
Boat Launch. Call 425-257-8305 or 425-257-8304 for more
information.

Ed Schulz
Everett, WA