This platform is located on eastbound Highway 90 (on the Causeway), close to the Bluegill Restaurant, I think. I'll confirm and edit with more exact location info.
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.
b
Incubation Initiation
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.
c
Clutch Hatching
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.
d
Nestling Count
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
e
Fledgling Count
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.
f
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.
x
Nest Failure
Look for signs of nest failure like adult abandonment, adults no longer incubating eggs or feeding young.
I just happened to notice this nest as I was driving across the bay on the Causeway this afternoon. I had seen the platform there last year but with no nest at all. I'm happy to see that it is now occupied and this might explain the "fourth bird" I've noticed hunting from the light poles on the I10 Bayway this summer. The other three are the male and female from the Bankhead nest and their wing-flapping hatchling.