Trisha called to say that one eagle is now sitting very low in the nest and remained there over a two hour period of observation. This is very likely a sign that she is incubating. She may be hard to see, so visitors should take pains to see if she continues to sit low. This would be an earlier egg date than the past two years.
Tom Mitchell sent these photos of his from today, for posting.
You can barely see her peering out between the nest materials:
Re: Eagle probably laid first egg on December 11, 2010.
Subsequent observations over the next few days did not indicate that incubation was yet taking place.
Probable date of first egg was December 11, based upon hatch date of January 15, 2011, which is 5 weeks (35 days) subsequently. In previous seasons, first eggs were laid on December 13, 2008, and December 18, 2009. See the Eagle Milestones Spreadsheet at link above message list.