Nesting Timeline
The nesting timeline below is just an approximate guide. Every nest is different with respect to timing depending on factors relating to the individual birds, weather conditions and the like.
April to June
Adult Arrival
Two adults are around the nest. They will show bonding behaviors such as aerial sky dances, vocalizations, and the male feeding the female fish. About 14 days before the laying of eggs, you may see the pair copulating.
June to August
Egg Laying and Incubation
Females will lay 2 – 4 eggs. This is followed by incubation. Adults take turns sitting low in the nest incubating eggs. The incubation period can last about five weeks.
August to September
Clutch Hatching
Chicks hatch about 40 days after the start of incubation. Adults bring food to the nest and make “head bows” into the center. The chicks cannot be seen usually until they are 2 to 3 weeks old. In light of this, feeding behavior is the way to identify the presence of chicks.
September to November
Fledgling Count
At around 7 – 8 weeks old the chicks begin flying while still fed by the adults. This is the time to count the number of chicks who have successfully fledged and can be seen flying.
Any Time
Abandoned Nest
Sometimes the adults stop incubating the eggs or cease feeding the chicks and abandon the nest.
Adapted from Osprey Watch
Center for Conservation Biology