A Magical Afternoon at Arrowhead Marsh

By May Chen

In September of 2012, Wild Oakland received an e-mail from Tracy Sarita, who coordinates an after school Outdoor Club at an Oakland public middle school, Urban Promise Academy.  Tracy had inquired whether Wild Oakland did any education outreach that her students might tap into.  Since no such program existed at the time, Tracy’s e-mail was quickly circulated among WO’s members, seeking some kind of resolution.  Might anyone like to respond to this need?

Since I have some experience with nature education for children, I contacted Tracy with some ideas for her students.  After some initial mishaps, rescheduling and difficulties with transportation, Tracy and six of her Outdoor Club students finally made it to the Martin Luther King Jr. Regional Shoreline at 2 pm on Nov. 14.

I recruited the help of my friends Liz Sterns and Pattie Litton- we’re all docents at Audubon Canyon Ranch and Oakland residents.  Liz brought her spotting scope to share, and we all brought field guides and spare binoculars.  It turned out there was sufficient equipment for Tracy’s small group of eager troopers.  We started at the observation tower getting to know each other and taking in a panoramic view of Arrowhead Marsh.  I presented a brief history of the marsh, highlighting the efforts of various conservation groups and volunteers to restore what used to be the dumping ground for the Port of Oakland into the beautiful functioning marsh it is today.  We talked about the importance of salt marshes, including why California has only 10% of its original salt marshes left.  We passed around pictures of the Clapper Rail, the poster child for wetlands conservation, and a bird that has made Arrowhead Marsh a mecca for birders.

When Tracy and I agreed on Nov.14 for the field trip I had quickly checked the tide tables for the day.  With a new moon the day before, the highest tide for Nov. 14 was forecast at 11 am, followed by an extreme low tide at 6 pm.  I figured we’d do just fine in the afternoon, being there during receding tide.  I did not have high hopes for Clapper Rail sightings, as those are reputed to be best during extreme high tides when the birds are flushed from their hiding places in the marsh.  But I figured the kids would at least get to see some ducks and shore birds…

We walked gingerly onto the boardwalk over the marsh.  We thought we heard some distant clapper rail calls.  As we approached the end of the boardwalk, three Northern Shovellers were swimming and dabbling in the shallow water.  The children delighted in watching the ducks tip their rear ends up in the air while their heads went underwater in search of food.

“Oh, my god, there’s a clapper rail!” someone exclaimed in a loud whisper.  All heads immediately scanned around for the rare, endangered species.  Sure enough, a chicken-sized brownish bird with a long, bright orange bill was swimming from one island to another right in front of us.  The children naturally knew that they needed to be quiet, and instinctively reached for their binoculars.  In no time, Liz had her scope trained on the bird, and the children lined up for their view of a life time.  The children laughed at how the bird was straining to swim, its head jerking back and forth like a pidgeon’s.  Pattie commented that it’s a wonder that the clapper could swim at all, having unwebbed, chicken-like feet.  While I was congratulating ourselves for how lucky we were, another Clapper Rail was spotted foraging along the shore of an island across from us. The bird’s plumage glowed in the golden autumn light.  It’s reputation as an elusive, secretive bird not withstanding, our clapper took its time checking out all the nooks and crannies along the waters edge in our full view, occasionally downing a morsel of food picked up from the mud.  We all fell into an awed silence.

California Clapper Rail

Another clapper rail showed up foraging along the shore of another island.  Then, much to everybody’s surprise, yet another showed up within five feet of us, next to the boardwalk.  Surely it could see and hear us, but it made no attempt to hide.  It walked slowly towards us, pecking at the mud, and occasionally looking up, giving us ample opportunity to photograph it.  Even with my humble point-and-shoot camera, I managed to get a decent picture.  I was delighted that the children were so focused on watching the clapper’s every move.  They finally relented when I suggested we moved on to another spot to look for other birds.  As we returned along the boardwalk, a startling clatter of clapper calls suddenly erupted from beneath us, followed by returning calls from the other nearby islands.  The Clapper Rails are certainly doing well at Arrowhead Marsh!

As the tide receded further exposing the mudflats, a flock of Black-necked Stilts appeared from nowhere to forage on the mud.  The children learned that because these wading birds are equipped with long legs they can forage in shallow water without getting their feathers wet.  The children delighted in the stilts’ bubblegum-pink legs. We spotted a couple of Yellowlegs and noted their restless foraging behavior in the shallows.  Again, the children laughed.  They loved that these shore birds have such simple, descriptive, easy to remember names!  A Snowy Egret was foraging in a narrow channel in the marsh.  Pattie told the children that these birds have bright yellow feet.  As if on cue, the egret lifted off giving us a great view of its golden slippers.

I made a point to draw attention to the cordgrass growing abundantly in the lowest level of the marsh.  Because of its highly efficient photosynthesis, this humble plant is the major contributor to the productivity of the salt marsh, serving as the base of its food web.  The plant is remarkably well-adapted for this salty habitat.  There are salt glands on its leaves that help expel the excess salt and its stems are hollow, allowing oxygen to reach the submerged roots.  Small flags were visible in the marshy islands where volunteers have planted native vegetation in the ongoing restoration effort.  Pattie went to the waters edge to pick a bit of Pickleweed to show the children. We learned about the hardiness of this strange-looking, succulent plant and how it is adapted to this inhospitable habitat.  As we walked pass an interpretive panel I pointed out a picture of the Salt Marsh Harvest Mouse, another denizen of the marsh that can actually feed on the salty Pickleweed.  The diminutive mammal is so rare that even I have yet to see one.

Another interpretive panel showed a map of the Pacific Flyway – an excellent stop to talk about bird migration.  Unlike the resident birds such as the Marsh Wrens and the Clapper Rails, many of the birds we saw today were migratory birds on their way south, following the sun and seeking food.  Places along the California coast like Arrowhead Marsh are important refueling stations, where these long distance flyers may rest and feed.

We headed towards the bridge over San Leandro Creek and the fast-receding tide water was gushing into the bay from the creek creating strong eddies.  In deeper waters by the fishing dock, some grebes could be seen. There was an elegant Clark’s Grebe with bright yellow bill, and a smaller, brown Pied-billed Grebe. We observed yet another feeding behavior in the water birds – diving and chasing after fish!

As we stood watching birds on the shore across from us, one of the students exclaimed, “Look, that bird looks like a bat!”  Puzzled, I looked around, and suddenly realized what he was referring to.  There was a cormorant perched on a rock with its large wings outstretched in the afternoon sun. I explained that unlike other birds, the cormorant does not have an oil gland with which it can waterproof its feathers.  The bird dives and swims underwater to catch fish.  After a bout of such foraging, the cormorant needs to dry out its feathers.   Some ground squirrels had come to the shoreline to look for food, providing us with much mirth and entertainment.

By then it was close to 4 pm and Tracy reminded us that they had to head back to school.  Returning to the parking lot area, we wrapped up our excursion in a circle, each child naming his/her favorite thing on the field trip.  Needless to say, watching the Clapper Rails was the highlight for most of the children!  We reflected on how fortunate we were that the Arrowhead Marsh had been saved, as it is home to so much wonderful and unique wildlife.

On the dock at Arrowhead Marsh

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