May 26, 2005
Nest Maintenance
We had a nice shot this evening of the female using her balled up talons to turn the eggs. Click on the thumbnail for a larger version.
Despite this dramatic photo, normally when the osprey parents are incubating the three eggs, it looks like they're spending almost all their time just sitting and eating. But one important activity that is ongoing is nest maintenance. The male is often bringing new materials to the nest and the female spends a good bit of time rearranging the nest to her liking.
We saw quite a few shots in the last week that showed the pair adding to the nest and redecorating in preparation for the coming family. Sometimes they work together to move the items around and sometimes the female will even use the material to cover the eggs.
Among the items that we've seen added include tree branches, sod, cornstalks, and what looked like a phragmite reed (an invasive plant in Chesapeake Bay wetlands). But the one item missing this year -- and something we saw last year -- is a bird wing.
Ospreys have a rather unusual habit of bringing the wings of other birds to their nest and using them as nesting material. Ospreys are normally strict fish-eaters (we've never seen them eat anything else at the Blackwater cam nest), and they don't eat carrion. In addition, ospreys have not been known to attack other birds unless provoked, yet somehow they find bird wings to bring back to their nests.
Acclaimed ornithologist Arthur Cleveland Bent reported that ospreys have been seen bringing the wings of ducks and gulls to their nests. And back in 1927, biologist Chester Lamb recounted that during a trip he made to isolated Natividad Island in California, he saw ospreys using bird wings extensively in their nests. Peregrine falcons had killed many black-vented shearwaters that inhabited the island, and Lamb reported that all the osprey nests examined were made partly of black-vented shearwater wings; and at one nest in particular, all except a part of the foundation was entirely made of the wings.
Last year, we saw photos of our cam ospreys adding a large bird wing to their home and then working together to reposition the unusual item. Where they got it from and why they liked having it in the nest still remains a birding mystery. :-)
A technical note: Due to the upcoming American holiday, some of us will be out of town. We ask for your patience if any technical glitches happen during the weekend as it might take a little longer for us to get them fixed.
Until next time,
Lisa - webmaster