Look for 2 adults on the nest. The adult pair will show pair bonding behaviors such as vocalizations, aerial sky dances, and the male feeding the female fish. You may see the pair copulating, which typically begins 14 days before laying eggs.
Females will lay 1 - 4 eggs at a rate of one egg every 1 - 2 days. After laying, incubation starts. Look for adults taking turns sitting low in the nest incubating eggs. The incubation period can last 35 - 43 days.
Chicks hatch ~39 days after incubation begins. Look for adults bringing food to the nest and making "head bows" into the center. Chicks typically can't be seen until they are 2 - 3 weeks old, so feeding behavior is the only way to know chicks are there.
Around 4 weeks after hatching, look for the heads of chicks to show over the rim of the nest, particularly when adults bring food to the nest. Other times they lie flat and are harder to see. Count the number of chicks in the nest before they learn to fly
Chicks begin flying around 7 - 8 weeks old, and are still fed by the adults. Count the number of chicks who have successfully fledged the nest and are observed flying.
Chick Last Observed
4 - 10 weeks after fledging, chicks begin leaving the nest area to migrate south, once they have learned to fly and feed themselves. Record the date that the last chick left the nest.
Look for signs of nest failure like adult abandonment, adults no longer incubating eggs or feeding young.
I can't actually see into this nest, so I need to watch for activity that indicates an egg is present. Today I witnessed the female nearby and the male, after some stick shuffling and personal grooming, sat down into the nest as though he were incubating an egg. The last time I watched this nest was April 1, and neither osprey was sitting in the nest.
I visited this nest July 22 and saw both fledglings in the nest, and both the mother and father nearby. In the photo I added, you can see the mother in the foreground, followed by the two fledglings, followed by the father.
It isn't possible for me to see into this nest, so I cannot tell when the first leg was laid or hw many were laid. Today was the first visit (last was a couple of days ago) where I first saw nesting behavior.
I have been able to verify that this nest has two fully grown young ospreys. I haven't seen them fly, yet, but I haven't checked this nest often. I will look for evidence of fledging (empty nest) my next time out.
I just discovered this nest a few days ago while monitoring two other nests beneath the bridge. I have seen the mother and one young osprey, but I have not actively monitored this nest and we are well into the fledging time period. I'll post anything else I see that is notable, including whether I can see more than one young osprey in the nest.