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Observations & Images
5 March 2006
1st day of incubating

The Eggs Have Arrived!

The big day is finally here! Neither Osprey seemed to be in sight as I set up but a close look revealed an Osprey, the female as it turned out, to be hunkered down in the nest. Her subsequent actions, and the male's, point to the unmistakable conclusion that the female began laying her eggs sometime between my departure late in the day on 4 March and my arrival back at the nest the afternoon of 5 March.

About every 20 minutes or so the female would get up and perform what appeared to be a delicate procedure moving the egg or eggs around in the bottom of the nest.

Alan Poole writes that "Osprey eggs are about the same size and shape as those of large domestic hens." He goes on to say that eggs are usually laid one to two days apart for a total of three to four eggs.

She would then take some time slowly settling herself down back into the nest. Her slow deliberate movements show care to bring the eggs back into her feathers and against the brood patch, an area of skin that develops on the breast in both parent Ospreys where blood vessels come to the surface to help regulate the temperature of the eggs during incubation.
The female Osprey in another position in the nest.
And again, the female Osprey assumes another position in the nest. Alan Poole writes that the average incubation period is 39 days with a range of 35 to 43 days.
Eventually the male Osprey returned carrying a piece of fish.
The female quickly retrieved the fish from the male.
Once the fish was in her grasp, the female flew off with it. From this angle, the fish may be something a fisherman threw away judging by what appears to be a straight cut from a knife rather than a fish the male Osprey caught fresh and consumed part of which would, one would think, leave a much more ragged appearance.
The male Osprey immediately showed the exact same behavior as the female had shown in the nest. He carefully arranged the egg or eggs before he, himself, slowly settled down over them. Here his head is barely visible over the nest wall. Alan Poole writes that in studying Ospreys around the world there is much variation in how much time the male will incubate the eggs. Sometimes males will incubate for as little as 13% of the time to as much as 66% of the time. The pair should trade off incubating during the day but research shows it is the female that takes the entire night shift.
The female perched nearby and consumed the fish the male had brought her.
Done eating, the female, shown here, relaxed for a short while before flying back into the nest where she immediately changed positions with the male. The male worked a little on the nest wall, actually bringing a small twig back he collected on a short flight through the pines. His work did not disturb the nesting female and, as the Sun set, the male stopped his labors and was seen perched on the side of the nest.


A newcomer to the nest area is this juvenile Wood Stork.
A still constant companion while I watch the Ospreys is the juvenile Little Blue Heron who now comes quite close depending on how quiet and still I remain.
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OspreyWatch by Bob Montanaro
www.lunarcabin.com - - - - www.ospreywatch.org