Friends of Sausal Creek

by Birds of the Upper Sausal Creek Watershed: Past and Present

By Martha E. Lowe

Since last February, the Friends of Sausal Creek bird-monitoring team has gone out once a month early in the morning to identify and count birds at specific locations in Dimond Park, Dimond Canyon, and Joaquin Miller Park. Our intention has been to create a list of birds and collect baseline data on species abundance and diversity in the watershed today.

I am a member of the bird-monitoring team, and not long ago, while I was doing research at the Bancroft Library, I came across an 1886 bird list produced by Walter E. Bryant, a local taxidermist. Comparing that list with our monitoring data shows that the kinds of birds that live here have changed, just as the Sausal Creek watershed itself has changed.

One hundred years ago, the Oakland hills were dominated by grassland and chaparral, and there are numerous birds on Bryant's list that depend on open country. In 1886, meadowlarks and bluebirds were abundant, horned larks were common, and burrowing owls and black-shouldered kites were rare but formerly common. These species are still relatively common in nearby areas where appropriate habitat remains, but they are now unknown or extremely rare in our watershed. While loss of habitat was the main cause of the decline of these species, other factors were also at work for example, breast of meadowlark was apparently considered a delicacy in the late 1800s!

On the other hand, a species such as the turkey vulture, locally rare in 1886, is common today. In the 1850s, California condors were still common, and since condors and vultures shared a similar ecological niche, it is likely that they did not coexist. The condor does not appear on Bryant's list, so it must have been extirpated by 1886, and the turkey vulture was probably just beginning to fill the condor's vacant niche.

Historically, the Steller's jay, chestnut-backed chickadee, and red-breasted nuthatch, which are some of our most common hill species, were rare. These birds prefer coniferous forests or pine-oak woodlands, which were in short supply in 1886. Today they are found in the redwood and mixed-evergreen forests that now cover the hills.

By comparing data with past records, we have found evidence that habitat change affects bird populations. The upper Sausal Creek watershed has lost bird species dependent on open country, while its forest-dependent species have increased.

The next bird-monitoring event is scheduled for 7:30 a.m., Saturday, February 13. Anyone interested in birding is welcome; we meet near the Dimond Rec Center. Newcomers are encouraged at all the Friends' events and are especially needed to help plan and carry out our workdays. For more information, call Anne Hayes of the Aquatic Outreach Institute at (510) 231-9566.