Friday, January 28, 2011

2010 Nesting Season

2010 was a very interesting season. We all hope for a successful nest and look forward to observing eggs hatching, nestlings growing, and their first flights. It's always disappointing when a nest doesn't produce young. That said, this was a very interesting nest to observe, with a great cam!

Nesting Dates

First adult: 3/27
Eggs: 5/16, 5/19, 5/23, 5/28
Female last seen: 8/26
Male last seen: 8/28

After a month spent coping with intruder and territory issues the resident pair claimed their nest. It was amazing to watch the nest go from bare to huge in less than 2 weeks, in fact, so large the cam needed to be adjusted!! The Ospreys wasted no time getting down to the business of eggs.

The female did not incubate the first fact, she didn't incubate the entire season, she did, faithfully, stand guard from the nest perch.

The male started incubating after the second egg was laid. He continued to incubate the eggs until 6/18...the first egg was at day 33 (osprey eggs hatch between 35 and 42 days). The male behaved exactly as he would in a 'normal season'. He incubated, brought in nesting material and fish for the female. Interesting, when he realized the female was not incubating, he began covering the eggs with nesting material before leaving to fish. Covering the eggs made it difficult for observers to decide how many eggs were in the nest, but gave the eggs extra protection from predators...a very good male!!

After he stopped incubating he continued to bring fish to the nest, for the entire season, as he would if there were young to care for. The female continued guarding the nest, as she would have done with young in the nest. The male also continued, for the entire season, to bring nesting material. This is unusual, adding nesting material stops when the nestlings are getting ready to fledge. This may have been an attempt to secure his claim on the nest for next season.

The female's migration date was about 2 weeks after the young would have fledged, a normal time for the female.

The male's migration date was 2 days after the female left. This is the normal time he would have started migration after his last juvie migrated. The difference is, the female was the one he fished one to fish for...migration.

I do believe this is our past seasons resident pair(98% for female, 100% for male), there were 4 eggs, and the late start was caused by intruder/territory issues resulting in the nest not producing young. I've changed my opinion several times on the number of eggs, identifying the female and male, and the cause of a late nesting. At the start of the season, there were very few sightings of ospreys on the nest, and those were brief. A challenge for sure, a learning opportunity, absolutely. After many hours observing the nest, on cam and on site, reading posts from experienced cam observers on 3 forums, and comparing 2009 nest pics, I believe... past resident pair...4 eggs.

I encourage anyone that followed the nesting season to post any observations, photos, questions or opinions.

Head Marks 2009 & 2010 (click to enlarge)

On the issue of how many eggs, this is a pic posted on the Hancock Forum, by member BET, 5/31. I have pics from 5/28, but BET has the best.

We can now look forward to our Ospreys returning to their EGG READY nest, for a great 2011 season!!!