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.
10:45 AM - Zero Ospreys. Fish Crow standing in and on edge of Osprey nest atop crane. Vocalizing, and debris falling. Is he protesting/dismantling it, or guarding it and waiting to welcome an Osprey? (30 minutes and a few miles away, I observed 4 vocalizing American Crows at another Osprey nest being built by an Osprey.)
7:32 am - Spotted adult on crane across from boat ramp. Later saw it - or a second - hunting behind Kelly’s restaurant. After several failed attempts (while being chased by 3 crows), it caught a fish and headed west down river back towards crane. 41°F and overcast
10:35am: From Battlefield Blvd, I spotted Osprey atop tower-like structure on Tilden Ave, near last year's nest. Drove and parked at Tilden Ave. Photoed two men (one masked?) climb tower. Osprey flew off as they approached the top.
On 3/26/12, the first visit to this nest, we saw one of the osprey bring material to the nest. There was also a short mid-air encounter between one of the osprey and a juvenile bald eagle.
Bases on different zoom levels of the map, the barge is apparently moved periodically, so can't vouch for the GPS location at any given moment :)