No vacancy on float for harbor seals

The rain ended, the sun came out, and so did the harbor seals at Alameda Point.  So many of them came out of the water to warm up on their new float on January 5, hardly any of the structure was visible.  The number has many observers asking for a second float.

Seventy harbor seals rest on new float at Alameda Point on January 5, 2017.
Seventy harbor seals rest on new float at Alameda Point on January 5, 2017.

The regional ferry agency installed the new float after removing an old Navy dock used by the seals, in order to make way for a ferry maintenance facility.

“I nearly keeled over when I saw the platform,” said Lisa Haderlie Baker, harbor seal monitor and Alameda resident.  “So many seals packed cheek by jowl, literally, that I had to count them four times using binoculars to make sure there were 60 of them, at least, basking in the sun, which I knew had to be close to a record.  It was a tremendous thrill.”  Continue reading “No vacancy on float for harbor seals”

Ospreys nest successfully in 2016 at Alameda Point

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.

Two young ospreys on June 8, 2016, at Alameda Point Seaplane Lagoon.
Two young ospreys on June 8, 2016, at Alameda Point Seaplane Lagoon.

Continue reading “Ospreys nest successfully in 2016 at Alameda Point”

Ferry agency, volunteers help the least terns

Three thousand tons of sand was added to the nesting grounds for the least terns at Alameda Point in late February and early March. In the weeks that followed, volunteers from St. George Spirits and the Boy Scouts and Cub Scouts came out to help make the site ready for the arrival of the terns in mid-April.

Sand being delivered to the least tern nesting grounds at Alameda Point on February 25, 2016. Bay Bridge in the background.
Sand being delivered to the least tern nesting grounds at Alameda Point on February 25, 2016. Bay Bridge in the background.

The Water Emergency Transportation Authority (WETA) paid for enough sand to cover half of the 9.6-acre nesting area with three inches of sand, as well as for grading. The weeklong delivery of sand was a conservation mitigation requirement for the impact that WETA’s new ferry maintenance facility will have on the terns’ feeding area. As many as 12 ferries will make up to four passes per weekday through the Alameda Point Channel where the terns frequently dive for small fish.

Wind and water erosion take their toll on the sand substrate lying atop old airfield taxiway pavement, requiring periodic replenishment. This latest delivery of Angel Island coarse sand has built up the sand depth on much of the site to the point that it’s starting to feel like a real beach underfoot. Beaches are the traditional nesting habitat for terns. Continue reading “Ferry agency, volunteers help the least terns”

Brown pelicans display beauty during trying times

About 100 California Brown Pelicans made an unusual appearance on the old wooden dock on the south side of Alameda Point near the U.S.S. Hornet on December 23. The visit provided a rare close-up view of this colorful and iconic bird, but also a reminder of their struggle to survive as a species. Only one of the pelicans could be identified as a one- or two-year-old.

Brown Pelicans resting on old recreational boating dock on south side of Alameda Point in December.
Brown Pelicans resting on old recreational boating dock on south side of Alameda Point in December.

During the past four years, the breeding rate for California Brown Pelicans has been dismal. This recent trend has been directly attributable to the dwindling supply of sardines along the California coast, according to a Brown Pelican status report issued in October by the Washington State Department of Fish and Wildlife. The sardine population has dropped so low that in April of 2015, the agency responsible for managing Pacific Coast fisheries banned commercial fishing of sardines until the end of June 2016.

In May, the U.S. Fish and Wildlife Service urged the same agency to consider additional management measures to stave off a decline in northern anchovy, another important food source for pelicans and other marine life.

California brown pelicans resting on Alameda Point dock

Brown Pelicans were removed from the federal endangered species list in 2009 with great fanfare after recovering from the devastating effects of the agricultural pesticide DDT on their eggs. But they no sooner recovered from chemical contamination than they fell victim to a plunge in food supply.

“Although most essential nesting and roosting habitat throughout the subspecies’ range is protected, the California Brown Pelican has experienced unusual mortality events and a multi-year decline in breeding success since delisting, both of which appear to be due to the lack of adequate forage,” wrote the U.S. Fish and Wildlife Service to the Pacific Fishery Management Council on May 14, 2015.

Brown pelicans roosting on the dock

About 10 percent of California Brown Pelicans nest on two islands in Channel Islands National Park off the coast of Southern California. The remainder nest and rear their young off the western coast of Mexico.

The University of California at Davis and the Mexican national conservation agency conducted a study of the 2014 nesting season off the coast of Mexico. The U.C. Davis news summary of the study results stated, “The scientists found that this year, areas that typically host hundreds or thousands of nesting pairs held only a few hundred at most, and in some cases zero nesting pairs.” Co-author of the study, U.C. Davis wildlife biologist Dan Anderson, is quoted in the story saying, “That’s what we call a failure, a bust. The bottom dropped out.” Anderson has been monitoring Brown Pelicans for 46 years.

Brown Pelicans soaking up the sun during a rare visit to an old dock on Alameda Point's south shore.
Brown Pelicans soaking up the sun during a rare visit to an old dock on Alameda Point’s south shore.

Breeding normally begins in January. Whether the pelicans currently at Alameda Point will make the journey south is yet to be seen.

Breakwater Island along the south side of the Alameda Point Channel serves as the most popular resting site for Brown Pelicans on San Francisco Bay during the warmer months.

Immature (1 or 2 years old) Brown Pelican with all-brown head and neck, the only one spotted among about 100 pelicans on the dock on December 23, 2015.
Immature (1 or 2 years old) Brown Pelican with all-brown head and neck, the only one spotted among about 100 pelicans on the dock on December 23, 2015.

Immature Brown Pelicans are distinguishable by being entirely brown, except for their whitish underbelly.  By their third year, the neck becomes white and the head yellow.  During breeding season, the neck of adults becomes dark chestnut and the pouch under their bill becomes red. 

Reprinted on Golden Gate Birder, Golden Gate Audubon Society’s blog.

Featured on Bay Nature’s Nature News.

Further reading:

“Periodic Status Review for the Brown Pelican,” October 2015, State of Washington Department of Fish and Wildlife.

“Failure to launch:  California brown pelicans’ breeding rate dismal,” June 2, 2014, UC Davis News and Information.

“Letter from U.S. Fish and Wildlife Service to Pacific Fishery Management Council,” May 14, 2015.

Additional photos and video from December 23, 2015, Alameda Point:

California brown pelicans in breeding plumage at Alameda Point

California brown pelicans huddled on the dock

California brown pelican at Alameda Point

California brown pelicans in breeding plumage, Dec. 23, 2015, Alameda Point

Brown pelican stretching at Alameda Point

Bird sightings at Alameda Point – Fall 2014

A photo gallery of birds sighted at Alameda Point during the Fall of 2014.  They include:  Black-necked Stilt, Red-shouldered Hawk, Northern Flicker, White-crowned Sparrow, Cedar Waxwing, Chestnut-backed Chickadee, Northern Shoveler, Black-crowned Night Heron, and Western Bluebird.

Black-necked Stilt

Black-necked Stilt

Red-shouldered Hawk

Red-shouldered Hawk

Continue reading “Bird sightings at Alameda Point – Fall 2014”

Endangered Alameda least terns get a secure home

Alameda’s nesting colony of endangered California Least Terns has a new government landlord – and a secure home for the future.  After years of negotiations, the U.S. Navy transferred 624 acres of its former airfield at Alameda Point to the Department of Veterans Affairs (VA) on Monday, November 3.

Least Tern chick, adult with fish, and resting adult, next to tile used for shelter, June 2014.
Least Tern chick, adult with fish, and resting adult, next to tile used for shelter, June 2014.

The transfer includes the former airstrip that was adopted by Least Terns for nesting in the 1970s and that has become the most productive breeding site in California for that species. More than 500 acres – including the area used by the terns – will be preserved as a wildlife reserve. Continue reading “Endangered Alameda least terns get a secure home”

Ospreys nesting at Alameda Point interrupted again in 2014

In early June a pair of returning ospreys looked ready for the day in their newly made nest atop a parking lot light pole at Alameda Point, but they had no chicks to attend to. The pair’s first nest this season — on a nearby ship — had been removed during construction.  Their second attempt faced interference from another osprey.  By June, hopes for fledglings this year had faded.  An ad hoc group of osprey watchers is hoping a dedicated osprey platform can be erected at Alameda Point in a spot where competing interests and annoyances of daily commotion don’t intrude into the reproductive efforts of the ospreys.

Male osprey bringing nesting material to light pole near maritime ships at Alameda Point with female looking on.
Male osprey bringing nesting material to light pole near maritime ships at Alameda Point with female looking on.

In early March the osprey pair began building their first nest this year where they had nested last year — on a kingpost high atop the maritime ship Admiral Callaghan. The ship’s owner, the Maritime Administration (MARAD), had removed last year’s nest. This year MARAD moved quickly to stop the nest building to avoid potential delay to relocate a nest if ordered into service. “The Maritime Administration worked closely with the California Department of Fish and Wildlife on dismantling the nest and installing deterrence devices on March 19 prior to any eggs being laid,” said Alameda resident Harvey Wilson, who has been monitoring the ospreys at Alameda Point.

Crew removing osprey nesting material from kingpost on Admiral Callaghan maritime ship at Alameda Point, March 2014.
Crew removing osprey nesting material from kingpost on Admiral Callaghan maritime ship at Alameda Point, March 2014.  Photo by Harvey Wilson.

But that removal didn’t end the ospreys’ interest in the ship, at least not for the male osprey. He soon started bringing sticks to a lower-level hoisting post on the ship. The female, on the other hand, took a liking to a light pole in the parking lot next to the wharf. After weeks of back and forth episodes of mating and nest building at both sites, the female won, and nest building started ramping up on the light pole. At one point, it appeared that the female was hunkering down in the nest, a sign that eggs had been laid and incubation had started. But soon another female osprey appeared, trying to lure the male from his duties and disturbing the composure of the female.  

Female osprey bringing nesting material to nest on parking lot light pole near maritime ships at Alameda Point - May 2014.
Female osprey bringing nesting material to nest on parking lot light pole near maritime ships at Alameda Point – May 2014.

The third osprey now seems to have moved on, and the original pair has continued to visit the nest, but the lateness of the season offers little hope that eggs will be laid again, if they ever were, this year.

Osprey with striped bass in early June 2014 near maritime ships at Alameda Point.
Osprey with striped bass in early June 2014 near maritime ships at Alameda Point.

The appearance of ospreys at Alameda Point, first documented in 2010, is part of larger Bay Area phenomenon of ospreys beginning to nest on the shores of San Francisco Bay. Osprey first began nesting in the San Francisco Bay Area in the year 2000, having moved their nesting range further south. There are currently 24 active nests on San Francisco Bay. One theory for the ospreys’ Bayside nesting interest is a reduction of silt in the Bay, making it easier for osprey to catch fish, their primary food source. The high silt levels are a legacy of the gold mining era during which streambeds emptying into the Sacramento River were blasted with water canons to expose gold particles. Ospreys normally return to the same nest every year, but the Alameda Point pair has now used three different sites. In 2012 they successfully raised their lone chick on an old light stand on the western jetty of the Seaplane Lagoon, their regular nest for three years.   For unknown reasons, they chose the heights of a maritime ship in 2013, and in 2014 a parking lot light pole.

Osprey pair on their light pole nest April 18, 2014 as nest building continued.
Osprey pair on their light pole nest April 18, 2014 as nest building continued.

An ad hoc group of osprey watchers that includes members of the Golden Gate Audubon Society have been discussing with the city the possibility of erecting a permanent osprey nesting platform on the western side of the Seaplane Lagoon. “City staff has been and is willing to continue to work with interested members of the local community to potentially establish an osprey platform at Alameda Point,” said Jennifer Ott, Chief Operating Officer for Alameda Point.  “The identification of an appropriate location for this platform will depend on a number of factors, including approval by the United States Fish and Wildlife Service.” In March of this year, the city of Richmond’s Public Works Department assisted with the installation of an osprey platform at Pt. Molate, which helped divert nesting efforts from a utility pole with live wires. PG&E, with extensive raptor nesting diversion experience throughout California, has offered to install a pole and nesting tub at Alameda Point for free.

City of Richmond public works employee after installation of nesting tub at Pt. Molate.
City of Richmond public works employee after installation of nesting tub at Pt. Molate – March 2014.  This photo and three below are by Tony Brake.

“It is difficult to know what the ospreys feel or how they respond or what their capacity is for all the activity that goes on around them, but this season certainly challenged them,” said Alameda wildlife biologist Leora Feeney.  “Providing safe platforms for them out of busy corridors would serve everyone better.”

Female osprey arranging nesting material with male looking on.
Female osprey arranging nesting material with male looking on.

Published on the Golden Gate Audubon Society’s blog Golden Gate Birder.

See also: