The eggs hatch. At the earliest this could happen today, but don’t be surprised if the first chick doesn’t hatch for a couple of days. Even after the first egg hatches we may not be able to see the chick because it would be tucked low in the nest bowl. We would, however, see a change of behavior in the adults. When the adults are covering young they will be slightly more raised over the eaglet than they would over an egg. The real confirmation will either be the observation of a chick or the adult feed a chick.
The eggs fail. An obvious sign that the eggs have failed is the adults leaving the nest. We have seen the birds leave the nest for up to thee hours. I would say we could confirm a failure if the birds are gone from the nest for 12 solid hours. It is also possible that the birds will over incubate the eggs and remain incubating the eggs past when they are due. Then at some point the bird’s hormones will tell them that the eggs are nonviable and they will leave the nest. In either case of the birds abandoning the eggs, Chris DeSorbo from BRI would climb the nest and collect the eggs. We would then run these eggs for at least mercury, but as funding permits, possibly 101 other contaminants including PCBs, DDT, flame retardants (PBDEs), and water resistant chemicals (PFCs).
If these eggs do fail to hatch, there is a very, very slim chance that they would make another attempt this year. These eagles are one of the earliest nesting pairs in the state and there might be time for them to try again. However, this is not common with eagles and most likely they would wait until next year.
Keep up all your great and helpful observations.
Wing Goodale, BioDiversity Research Institute