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.
The endangered California least terns that nest on the old airfield at Alameda Point are well protected during their April to August nesting season. Fencing keeps people away from the 10-acre sandy nesting site, but it won’t stop other birds and mammals from getting to the eggs and the helpless chicks. Only a well-armed and outfitted predator management officer can effectively deter other animals.
Every year, the U.S. Fish and Wildlife Service hires a wildlife biologist from Wildlife Services, a division of the U.S. Department of Agriculture. Typically used for protecting crops and livestock, the agency is also hired to protect dozens of endangered species every year. The most recent field report available for Alameda Point is for 2019, obtained through the Freedom of Information Act.
The report describes a variety of methods used to deter or eliminate threats to the nesting terns. First, loud noises and bright flashes of light are fired from a gun to frighten away an avian predator, called hazing. Second, the wildlife biologist drives a vehicle toward an avian predator, another form of hazing. Third, predators are trapped. And fourth, as a last resort, the biologist is left with no other choice than shooting the predator with a shotgun or rifle or euthanizing.
The cypress trees in the wetland near the proposed DePave Park at Alameda Point have served as a safe and secure nesting site for Great Blue Herons for many years. This year is no exception, despite the trees having died and barely standing. On May 7, Audubon Society bird observer Dawn Lemoine counted 13 juveniles in the nests.
Location, location, location! But for a fenced-off dilapidated navigation light stand on a jetty at the Seaplane Lagoon, ospreys would not have had a successful nesting season this year.
In late August two adult ospreys took flight from their Seaplane Lagoon perch for parts unknown with two healthy offspring. It was a welcome sight because for the past three years a series of frustrating avian soap operas featuring other ospreys and unwanted nesting attempts aboard the maritime ship Admiral Callaghan were marked with failure. Previously in 2012 they had raised one chick, the only other recorded case of osprey reproduction at Alameda Point.