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Field Log
Field Log is a quarterly column that provides Bird Observatory volunteers and staff the opportunity to share the connections with nature formed through their field experiences!
Winter 2007 - Egad Egrets! A New Colony at Harbor Bay
Crazy. That was my first reaction last June when my friend, Reyla Graber, telephoned me to report she had just seen both Great Egrets and Snowy Egrets nesting and feeding young in a mature pine tree along a busy Harbor Bay lagoon path.
The Harbor Bay project is a part of Bay Farm Island, a portion of Alameda, and its lagoons have been in existence about 30 years. Historically Bay Farm Island was the location of extensive marshes between what later became Oakland Airport and Alameda, and an important stopover for birds migrating along the Pacific Flyway. Most of that ended beginning in the 1950’s with the draining and filing of the marsh and the coming of a large sanitary landfill, the construction of two golf courses, and extensive commercial and residential development. The lagoons were built as amenities for homeowners alongside them, and not for wildlife enhancement.
So far as I was aware, the area was now devoid of any breeding birds larger (or more interesting) than a Rock Pigeon, other than the weirdly hybridized, sedentary Mallards and the odd Cooper’s Hawk or White-tailed Kite which might show itself. Even the numerous American Coots, which were everywhere in winter, migrated elsewhere to breed.
Nevertheless, I agreed to meet Reyla at the location she described the next morning. I walked the lagoon path to the indicated location maybe 100 yards from the Safeway Supermarket. Approaching the area I first heard a “whooshing” noise from overhead. I looked up and was awestruck by a beautiful array of perhaps 30 juvenile white egrets decorating the sparse foliage of a large pine tree growing by and partly overhanging the lagoon.
Most were Great Egrets, ranging in size from just hatched to adult (about 3 feet tall). The Snowy Egrets, about half as big as their larger cousins, were present in small numbers, still mostly on eggs or brooding their hatchlings. Reyla arrived shortly after I did. I promised I would not doubt her sightings again.
Neither of us had any experience with keeping records of observations for breeding colonies of birds. We eventually contacted the San Francisco Bay Bird Observatory (SFBBO). A meeting was promptly scheduled with Stephanie Ellis, the SFBBO Outreach and Education Specialist, who along with SFBBO biologist Cynthia Padula and volunteer Spike Marlowe provided us with forms and guidance for tracking the colony. Stephanie’s enthusiasm and moral support were infectious, and we were able to recruit several additional helpers in our watch over the colony.
During the ensuing days, we located birds and nests, and witnessed the feeding behavior of the young by their parents. Every arrival of an adult precipitated an attack by three to four hungry chicks. Over time the juvenile birds grew larger and more determined until the parent seemed in danger of being overwhelmed by deep thrusts of their dagger-like bills into the parent’s throat.
Our work included preparation of a map (thanks to the splendid work of Nancy Issel-Mayes, a retired science teacher) showing the position of each nest. Our final count came to not fewer than 18 nests in the pine tree and about 13 nests at a second grove a short stroll down the lagoon path. Productivity was extremely high, and we estimated more than 100 birds fledged from the two sites.
Almost as interesting as the behavior of the egrets was the reaction of the human population to this little bit of wildness adjacent to and/or above their houses. Although a few complained about bird droppings, the overwhelming reaction was one of shock and awe. Even devout joggers at times were stopped in their tracks by the sight of so many spectacular birds. Parents with children stopped to allow their children to take in this phenomenon.
The egrets themselves, in plain view and some perched as little as ten feet above ground, paid absolutely no attention to us.
In today’s busy world, the Harbor Bay egrets helped the human population for a few months to step back and take a look at the wonder and beauty of nature. The question now on everyone’s mind is: Will the egrets be back next year? Stay tuned...
-- Tim Molter
Tim is a resident of the Community of Harbor Bay Isle in Alameda and a dedicated Colonial Waterbird volunteer for the San Francisco Bay Bird Observatory.
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