Friday, March 07, 2008

Lola's first night on nest

Pale Male and Lola on the nest -- March 6, 2008
Courtesy of [click on photo to enlarge]

The date on which Lola first spends the night on the nest, which is also the time she and Pale Male begin to exchange sitting duty so the nest is attended at all times, is a landmark for Hawkwatchers. It may not mean that actual incubation has begun -- there are probably a few practice days that go by before egg laying begins and incubation begins in earnest. But we keep track of that date. It means that real incubation is imminent--will begin within a few days.

Yesterday, March 6, was the day!

Here are some "first night on nest" dates for past years

2007 -- 3/10
2006 -- 3/5
2005 -- 3/8
2004 -- 3/7
2003 -- 3/7
2002 -- 3/7
2001 -- 3/10
2000 -- 3/8

The eggs last hatched in 2004. Here are some hatch dates:
2004 -- 4/15
2003 -- 4/16
2002 -- 4/11
2001 -- 4/18
2000 -- 4/16

Because we can't see into the nest, we get these figures by observing changes in behavior. We assume a hatch has occurred when we see something like feeding fehavior happening: the female stands on the nest's rim and makes up and down movements to the nest's bottom.
It's not exactly rocket science. But still you can see the amazing regularity of the hawks' schedules.

Hurray, the process continues! And this year with a bit more hope.