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.
Pair continued to bring nest material and get wings caught in wire deterrent even after a chimney company placed more wires on the structure. Homeowner refused to take nest material off chimney but still wanted the osprey off the chimney...A group of people decided to erect a platform about 1/4 mile away on the marsh of James Farm at Joshua Cove (#6298) and miraculously that same day, 4-17-16, the pair relocated to the platform. Fingers crossed they can hold onto the newly constructed platform nest site but as of 4-20-16 they are binging nest material and thwarting other ospreys attempts at nest takeover!
I observed both birds flying in and out of the wire deterrent on the chimney. The one bird continues to bring nest material (most likely the male) and it appears the female spends more time in amongst the wires attempting to place the nest material. The nest has grown considerably since last week so the wiring is not keeping the birds away. Both birds are getting their wings caught on the wires. The home is for sale and unoccupied. I contacted DE F&W and gave the homeowners info to biologist in hopes someone can do a better and SAFER job of deterring this osprey pair. There is open marshland very close to this nest site that would be suitable for a nesting platform. Something I will look into for fall of 2016.
Nest has been rebuilt on a private home chimney for past 3 years. Nest is taken down by owner each winter. 2015 pair had 2 chicks, both died. 2016 winter homeowner placed wire on chimney to keep birds from nesting. 3-25-2016 both birds were on nearby piling and have begun flying through the wiring and rebuilding a nest. The wiring may be very hazardous for the birds.