Limited time opportunity! Catch a rare glimpse of nesting ospreys during a ride on the Seaplane ferry. The birds won’t be here much longer.

The adult ospreys have been bringing fish, the only food they eat, to their young for about a month. Their three fledglings are almost ready to start flying. Once the young birds start flying, they will hang around the nest for a week or two before they depart and have to quickly become adept at catching their own fish.

Ospreys nesting around San Francisco Bay is a relatively recent phenomenon, according to Tony Brake, a volunteer who has been monitoring ospreys around the Bay for over a decade. “There were no historical nesting records for ospreys until 1990,” said Brake.

Brake has observed 48 active nests around the Bay this year. Currently there are high densities of nests along the Mare Island Strait and the Richmond shoreline, which now has the largest number of active nests, totaling a little over 20.

“The number of nests did not start climbing in that area until after 2003,” said Brake. “In about 2009, they started to appear to the south.” That is the year they were first observed nesting at Alameda Point on an old light stand on the other side of the opening to the Seaplane Lagoon.

Alameda’s special nesting platform, used by this year’s osprey family, was erected by the city in early 2017, after osprey watchers had asked the city to repair and remount the old tipped-over light stand to serve as a second nesting platform. But after port manager Bay Ship and Yacht took a close look, they decided to instead build a brand-new stand with a basket-style platform to help the birds anchor their nesting material. In recent years, the ospreys have favored the new stand, possibly because it is more remote from human disturbance than the old light stand.

The young ospreys are distinguished by white tips on their feathers, which look like spots from a distance; golden feathers on the back of the neck; and darker eyes than the adults.

The ospreys, also known as fish hawks, catch fish by plunging their feet into the water and grabbing the fish with their hook-like talons. Some of the fish, such as Striped Bass, are head-to-tail almost as long as an adult osprey.

If you take a ferry ride from the Seaplane Lagoon terminal, you can see the nesting birds fairly close. Special thanks to the Captain of the Hydrus, Jari Hytonen, for slowing down more than usual for good photo opportunities. “I’m a regular on the morning shift out of Seaplane Lagoon, and I’ve been watching the pelicans and ospreys for the past maybe three months,” said Hytonen. “It’s always fun to see the birds in their habitat.” There are no other ferry routes that come this close to nesting ospreys, according to Hytonen.

Perhaps one day Alameda Point will have an osprey nest camera installed, like the one at Mare Island. For now, enjoy our local osprey success story as much as the ferry crews do, as you pass slowly through the entrance to the Seaplane Lagoon.

Contributing writer Richard Bangert post stories and photos about environmental issues and wildlife on his blog Alameda Point Environmental Report alamedapointenviro.com.