Young osprey at Alameda Point leaving soon

Parent osprey landing with fish as fledgling waits on right, with parent looking on.

This is the third year that a pair of ospreys has nested on the old light stand at the entrance to the Seaplane Lagoon.  This year’s mating effort produced one fledgling. 

As June draws to a close, the fledgling can been seen standing on the nest and going through a series of wing calisthenics as one of the parents looks on.  Occasionally a parent will fly in a circle around the nest as if to say, “Look, this is how it’s done.  It’s easy.”   Spending most of its time hunkered down in the nest, often with brisk winds coming in across the Bay, the fledgling waits patiently for the high points of the day – its parents returning to the nest with a fish.  It won’t be long before this osprey family will be winging their way back to the wild.

Fledgling osprey watching and waiting for its turn as parent eats fish.

Fledgling osprey exercising its wings above, while parent looks on.

Above and below – parent osprey appears to be giving flight demo as it circles nest with fledgling looking on.

Parent osprey lifting off from nest as fledgling sits, with other parent looking on.  Note juvenile colors and wing spots.

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See also 2011 osprey nesting at Alameda Point.

Protecting the California Least Terns at the Alameda Point Wildlife Refuge

Volunteers distributing oyster shells on nesting site in April 2012

The California Least Terns are arriving back at Alameda Point’s wildlife refuge to lay their eggs and raise their young.  The volunteers, who help maintain the site, and the US Fish & Wildlife Service (USFWS) biologist responsible for the tern colony, have never left.  They carry out maintenance tasks during the non-nesting season – September to early April – as well as help monitor bird behavior during the nesting season.

California Least Tern, with chick under tile, at Alameda Point

The California Least Terns return to California every April from Central America.  The old Navy runway area at Alameda Point is among the limited number of sites where these endangered birds come to nest.  Driven to adapt to a loss of undisturbed beach habitat, they began nesting at Alameda Point decades before the Naval Air Station closed in 1997.

While Navy jets would be disturbing for humans to live next to, for the terns the movement of the jets was predictable and easy to avoid.  That’s not the case on an increasing number of beach areas where people and pets can easily trample eggs in the sand and frighten the adult birds.

The Alameda Point colony is considered the most successful for this bird.  It is believed that the success at Alameda Point has led to new colonies elsewhere in California.

Looking south on a rainy day in April 2012 on the Alameda Point nesting site for CA Least Terns
Oyster shells on Alameda Point nesting site for CA Least Terns

Volunteers are recruited by the Friends of the Alameda Wildlife Refuge, a committee of the Golden Gate Audubon Society.  Activity at the Least Tern nesting site started ramping up in January this year as it always does, with guidance from the USFWS biologist.  Volunteers perform tasks such as removing weeds, repairing the mesh barrier that keeps chicks from wandering off or getting injured in the chain link fence around the nesting site, and distributing oyster shells to confuse hawks and other flying predators that often circle overhead during the nesting season.

Every year the US Fish & Wildlife Service re-positions all of the numbered cinder blocks that establish a grid pattern for recording bird behavior.  The blocks, along with all the other “tern furniture” – wooden A frames and clay tile that chicks shelter under and in, oyster shells, driftwood – are gathered up and set to the side after the nesting season.  This allows for easier weed control and for the sand and gravel surface to be graded.

The grid blocks are placed into position using a global positioning system for complete accuracy.  When Tern Watch volunteers or the Fish & Wildlife biologist observe activity, they record the data according to a grid letter/number.  Without a grid system, it would be difficult to record accurate data for hundreds of eggs and chicks, i.e., did a predator steal an egg last night, or is that the nest that had only one egg?

This year there are two training sessions for the Tern Watch program.

The public is invited to take a bus tour to the site on June 16th.  The annual event is hosted jointly by USFWS and the East Bay Regional Park District.  The bus tours leave from the Crab Cove Visitors Center in Alameda.  Advance registration is required and is handled through the park district.  (See comment below.)

Adaptive reuse of trash at Alameda Point

Lizards go rogue on city’s adaptive reuse plans, setting up multi-family housing complex outside of the adaptive reuse area.

The lizards hope that a tire pile discarded in the last century will be grandfathered into reuse plans because of their low-impact, eco sustainable practices.  Capturing rainwater, reducing global warming with plants, and keeping carbon-based tires out of the waste stream are cited as benefits.

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The Nesting Ospreys of Alameda Point – with video

The spring of 2011 saw the return to Alameda Point of a nesting pair of ospreys.  This pair set up their nest on the same light stand at the entrance to the Seaplane Lagoon as another osprey pair, or perhaps the same pair, had done in 2009.  Unlike 2009, this year the area is fenced off for cleanup work, making it difficult to get good photographs.

Remarkable in flight

It was a pleasure to watch the adults change shifts on the eggs and go off to catch fish.  Although they may sometimes prey on small ground dwelling animals, their diet is normally restricted to fish.  Often they could be seen heading north across the Seaplane Lagoon just inches above the water attempting to grab a fish.  What was remarkable to witness was their flying technique.  The osprey that I watched one evening was propelling itself just inches above the water for a few hundred feet, skimming the surface with its unique opposing claws ready to clutch a fish.  Up would go the wings to almost full vertical, and then come down in an arcing motion, cupping the air and thrusting it forward.

osprey hunting for fish
osprey with fish

When they returned with a small fish, they would usually perch on either the tip of an old metal post next to the nest or further west on the breakwater on a post with a horizontal arm.  After having their fill, they would share with their mate.

Unfortunately, vacation plans interrupted my photography before the chicks hatched and fledged.

While the osprey is not an endangered species, it is certainly an environmental asset and a beautiful creature to watch – so much so that many communities throughout the U.S. build perches around lakes and bays to attract ospreys during the nesting season.

Alameda should preserve nesting sites

Alameda should emulate these efforts and adopt a policy of not only permanently preserving the old light beacon stand that was used this year; we should also refurbish the other one on the east breakwater that is tipped over and hanging on by a chain.

We should make provisions for when the cleanup fencing is removed.  Perhaps a small fence at the entrance to the west breakwater to prevent deliberate or uninformed intrusions into the “nesting space.”  We could have organized viewing programs during nesting season.  One way to generate interest in the ospreys would be to install video cameras in some new poles next to each nesting platform.  A pole with a horizontal perch would be more useful to the osprey and a good way to have one camera facing into the nest and another one facing out toward the lagoon with streaming video.

To place the protection of osprey nesting sites in perspective, it is instructive to know that if the light stand used for nesting were a tree in a logging area of California, it would be illegal to cut it down.  Nesting sites are protected in our forests, and they should be protected here.  Without a proactive effort now, I fear that one day we will find that the old historic light stands have been thrown away.

The open space and wildlife resources that we have at Alameda Point are priceless.  We should make an effort to preserve them, especially when we have visitors like the ospreys.  

Click here > osprey slideshow on Flickr for more images