In this Issue
The San Diego Bird Atlas: A Conservation Tool for the 21st Century

Notable Observations

Reports from the Field
A Bad Year for the Least Tern
First Summer Record of the Winter Wren in San Diego County
The Helicopter Trip to the Santa Rosa Mountains
Portrait of P7: La Jolla

Focus On...
Plumbeous, Cassin's, and Gray Vireos

Progress Report

News and Updates
South San Diego Bay Refuge
Breeding Season Reminder
Bird Atlas E-Mail List-Server
WingDing September 12

The San Diego Bird Atlas:
A Conservation Tool for the 21st Century

The hope of many of us investing our energy toward the San Diego County Bird Atlas is that it be used as a tool for effective bird conservation. How might this happen? How might such a tool be used? The answer to these questions comes through understanding of the role of levels of scale.

One can look at a range map in a field guide or read the American Ornithologists' Union Check-list of North American Birds to get a fairly accurate idea of a species' general status in San Diego County--the coarsest level of scale. On the other hand, a regulator may require a developer to hire a consultant to delineate the territory of a single pair of endangered Bell's Vireos--the finest level of scale. Each of these levels has its uses. Between these extremes, however, lie the answers to many questions that can be addressed only at intermediate levels of scale. Our bird atlas grid represents the finest scale on which it is possible to achieve thorough coverage of all of San Diego County, with the time, money, access, and number and expertise of the participants available.

Here are some questions most appropriately addressed at this level of scale:

What areas support greatest bird diversity? If the goal is to conserve maximum diversity, such areas would logically be targeted first.

Where are the biggest populations of species X? Do they lie in areas already managed as wildlife habitat or are they in areas subject to development or degradation? Which populations lie adjacent to the urban growth front and which are more secluded, possibly allowing more time and greater flexibility for effective management?

Is species X adapting to the urban environment? Does it persist in enclaves of natural habitat within cities or only in broader expanses beyond?

Is species X of legitimate conservation concern or not? Our effort has already shown that some native species (Nuttall's Woodpecker, Western Flycatcher, Cooper's Hawk) are thriving in nonnative environments. Some species (Downy Woodpecker, Tree Swallow), even though scarce and requiring rare habitats, are faring well in spite of themselves. But others (Grasshopper Sparrow, Chipping Sparrow, Snowy Plover, Burrowing Owl) are revealed as, if anything, even more rare or restricted than I suspected before the project began.

What factors affect the distribution of species X? Is habitat type or vegetation community sufficient to explain it or are less conspicuous factors important too? Elevation, slope gradient or aspect, soil type, rainfall, fog versus sun, minimum winter temperature, maximum summer temperature, postfire succession, nearness of surface water may all play a role. Even if the exact role of various factors isn't clear, there will be enough to alert us that there may be more than meets the eye.

Some applications will be farther into the future. Twenty, 50, 100 years from now our successors will be able to look back at our results and compare them with current conditions. If the Multiple Species Conservation Plan (MSCP) or something similar is adopted, they will be able to ask whether this approach is working for species X but not for species Y--and possibly respond in time to make a difference. No one will be able to claim that the species had already been extirpated from an area before the management plan went into effect if our data show otherwise.

In San Diego County natural ecosystems face an especially difficult challenge: a human population growing at third-world rates but consuming resources at first-world rates. Despite all the wrangling over endangered species and conservation plans, grading for new developments continues at a frightening pace. Our wildlife is destined to compete for fewer and smaller patches of open space. Will the species living in these patches in 2000 still be surviving in 2050 or 2100? Will we have to accept an environment without Sage Sparrows, Roadrunners, and California Quail in exchange for getting one with California Gnatcatchers? Questions like these look back at me as I look into the maps our effort generates.

Will the San Diego County Bird Atlas be used as a tool for conservation? We will ensure that the information is circulated as widely as possible, to consultants, teachers, scientists, land managers, environmental planners, politicians, and, most important, citizens who will take action to shape our future. The project embodies the mission of the San Diego Natural History Museum and its Biodiversity Research Center, to provide scientific knowledge that promotes understanding of our region and inspires respect for the environment.

Philip Unitt