Proud parents Rosie and Richard are taking turns keeping the chick and two eggs warm.
The Golden Gate Audubon Society launched a live video stream in 2017 of the birds, who made their nest 75 feet above ground in a decommissioned World War II crane.
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The number of osprey was dwindling a couple of decades ago, but thanks to environmental protections, they are making a comeback, according to the Audubon Society.
This chick's siblings are expected to hatch within the next couple of days.
You can suggest names for the hatchlings at http://facebook.com/bayospreys.
See more stories and videos about birds and other wild animals.