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.
Nest failed. No new nesting material since the previous year, and the material of the last year has fallen over time. There was a male present in a tree nearby, but there is no reason to believe the nest is being refurbished. Light vocalizations can be heard upon leaving the observational area.
No individuals are present in the area or heard in the area. The nest is beginning to slide off the dead tree, which leads the observer to believe that there are no longer osprey here that are attempting to nest. No declaration will be made of failure until an additional observation is made.
Male flies in calling after about one minute into the observation. He calls loudly for the duration of the observation. Female is seen very close by in a dead tree. She seems to call as well, almost in response. Alternate male flies in and circles around the nest. Male that is observed in the nest calls and beats wings to ward off the invading individual who concedes after two attempts to land. The intruder is heard calling nearby in the woods upon retreat to observer's vehicle.
Upon first observation no individuals are seen in the area. One individual is heard but not seen in the immediate vicinity. Secondary observation male returns to the nest with large fish and calls extremely loudly, reminding the observer of a Red-tailed hawks call. Nearby, an alternate individual is noted to seem to respond to the loud male. Male leaves the nest upon approach.