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.
12:08 p.m. For as long as I have been doing osprey nest checks (since 2019), this tower has had no nesting material, and I have seen no sign of osprey at or near the area. Again this year there was no nesting material here, but when I got home and blew up my photo, lo and behold, there was a single osprey perched on the edge of the platform!! I will have to check back later and keep an eye on this platform in future seasons. There is not a large, clean body of water nearby. The closest would be Mt. Lake which is about 3 miles to the southwest. There is a small creek to the east, passing through the Great Meadows.
4:30 p.m. I found this nest platform after researching its location a bit more. I couldn't locate it two weeks ago. It is in the center of very large, flat fields with no river nearby. It is seen/accessed from Island Rd which leads into this broad, agricultural valley. I found the platform completely empty of any nesting materials and the only bird on the structure was a red-winged blackbird. It does not seem that this area would attract osprey as the irrigation ditches and various holding ponds in this valley are covered with algae, full of weeds, and not very full. I doubt these water sources would support the large fish that osprey would want.