The osprey laid their first egg yesterday afternoon! Osprey typically lay 2-4 eggs and there is a gap of 24-48 hours between each egg.
The picture above shows the birds at about 5:45 a.m. this morning. You can see mom on the egg and dad watching over her. The female does the vast majority of the incubation and the eggs take 36-42 days to hatch. The eggs are white with brown splotchy mottling.
PHOTOS: 1st Egg in Nest 4/24
Looks like the female is already incubating. This is pretty typical with osprey. Some birds wait until their full clutch is laid before beginning incubation. Other birds begin incubating on the first egg. If they begin on the first egg, then this is know as "asynchronous incubation" and the eggs will hatch in the order that she began incubating meaning that if there are 4 eggs in the nest, there may be up six days between hatching of the first and last egg. This means the first sibling to hatch can have a distinct advantage over smaller siblings born later.
Watch Live: Osprey Cam
It was this stage of the nesting process where osprey ran into problems from DDT. DDT used throughout the 1940's, 50's and 60's got into predatory bird systems and caused them to lay eggs with thin eggshells. DDT blocks and enzyme necessary for making calcium. The eggs would break during incubation. The three raptors most heavily affected were osprey, peregrines and bald eagles. All three species had major population crashes and the peregrine and bald eagle were both listed under the endangered species. Act. DDT was banned under the Nixon Administration in 1972 and all three species began a comeback. Today you can see all three species nesting in downtown Portland!
Finally a big welcome to the Sunnyside 1st and 2nd Graders who are watching Raptor Cam as part of their studies about birds. Please send me any questions that you have.