March 9: Incubation exchange

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March 9: Incubation exchange

This post was updated on .
I arrived at the nest at 9:55 AM this morning (March 9) and watched until 10:45 AM. The female (Jewel) was roosting on the center front nest support branch. The wind was strong and gusty from the east and the limb swung about wildly at times. The nest tree itself was swaying in the wind.

At first I thought the nest was empty, and after about 10 minutes I saw the top of the male (Pride)'s head. He then sat up higher and began moving around.

At about 10:25 they began calling to each other and suddenly Pride flew off and away from the rear of the nest. Jewel immediately occupied the nest. She briefly seemed to be arranging the nest or possibly tending the eggs or eaglets, but there was no indication that she was feeding any offspring. Jewel then settled out of sight in the nest and remained deep, quite certainly incubating unhatched egg(s).

Pride disappeared and I could not find him roosting in any of the usual locations.

Assuming from ground observations that incubation started on or after February 12, hatching of the first egg could be expected after MARCH 18.

This is the updated TIME LINE:

DEC 7 - consensus of ground observers that eggs were present that day or maybe a day or two before, as exchange of incubation duties was witnessed several times. Expected hatch date (5 weeks) on or before JAN 4
DEC 24 - Adult carrying grass to nest
JAN 2 - Incubation exchange; Male sitting high as if possibly "tenting" an eaglet, looking down. Female then also was sitting higher after exchange.
JAN 4 & 10 -- High winds buffeted the nest and part of the right side appears to have fallen down.
JAN 10 -- Both adults moving sticks, building up the rim.
JAN 25 -- Adults "copulated." It is not unusual for the male to mount the female outside the normal mating season, but might it be possible that she was fertile and receptive because the first brood was lost? There was a prey drop, usually a sign that eaglets are present, but was this a courtship "gift" which we has accompanied copulation in the past?
Remember that this happened with the same female (Jewel) during the 2015-16 season. The nest was damaged and first brood lost around JAN 19, 2016. We thought they had abandoned the nest around JAN 28, 2016, but they reappeared the next day. Her second clutch of eggs was probably laid around FEB 10 and hatched MAR 16; the first eaglet was seen on MAR 31, 2016. (We usually see an eaglet by the time it is 2-2 1/2 weeks old).
Between FEB 12 & 16 (this year) the adults have been sitting very deep in the nest and taking turns as if incubating and no prey drops have been noted.