The San Diego Bird Atlas: A Conservation
Tool for the 21st Century
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
Plumbeous, Cassin's, and Gray
South San Diego Bay Refuge
Breeding Season Reminder
Bird Atlas E-Mail List-Server
WingDing September 12
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
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.