San Diego Natural History Museum--Your Nature Connection[San Diego County Bird Atlas Project]

WRENDERINGS
The quarterly newsletter for Bird Atlas volunteers
Fall 1997

In this Issue
A Quick Look at the San Diego Bird Atlas' First Breeding Season

Notable Discoveries

Reports from the Field
Reflections from Square L12, Blue Sky Ranch
First Sooty Tern Nest for the Western Continental United States Found in San Diego County
Perspective from the State Parks

Focus On...
Gambel's Quail

News and Updates
Confused? Don't Hesitate to Ask for Help
Correction: "PM" Symbol
WingDing at the Wild Animal Park

A Quick Look at the San Diego Bird Atlas' First Breeding Season

With the San Diego Bird Atlas' first breeding season now drawing to a close we can look back over the remarkable progress we have made so far: 193 individual participants or teams, 259 of 479 grid squares adopted by observers (54%), one major grant application funded, several more submitted, over 650 daily field forms already returned (by 25 August), covering 102 squares, and over 18,000 individual records already entered in the computer database. Under the grant from Caltrans, Ann Klovstad has been working with incredible diligence four days a week, keeping our data entry up to date as the forms arrive and making progress on entering historic data from specimen and egg collections.

Even though we're still only a modest fraction of the way toward our goal of covering the entire county, enough data have arrived to merit our taking a peek at what they mean. Here are maps of four interesting species, showing simply where they have been observed-no analysis of breeding status yet.

The Northern Harrier and Coopers Hawk are two birds of prey whose adequacy of coverage under the Multiple Species Conservation Plan has been much discussed. Our results so far show these species are very different in their ecology and conservation status. Cooper's Hawk is quite widespread in coastal San Diego County, with many records even from urban areas of the birds nesting in nonnative trees in heavily trafficked areas. The map shows observations only after 15 April, when the birds are nesting and any migrants from father north should have left. Clearly, Cooper's Hawks are adapting to the urban environment and their conservation does not merit the level of concern of many other species. The Northern Harrier or Marsh Hawk, on the other hand, is not doing well at all. None of the reports so far is of confirmed nesting, and some participants questioned whether their observations even during the breeding season were of nonbreeding visitors. For example, in square L13, Mt. Woodson, Phoenix von Hendy recorded only a single harrier on 28 July - none earlier in the late spring or early summer. Apparently the bird was a post of nonbreeding visitor - possibly from a site nearby in the threatened Ramona grasslands.

Say's Phoebe has proven to be unexpectedly widespread. In addition to its expected breeding distribution in the Anza-Borrego Desert, there have been quite a few reports, including some confirmed nesting, from the coastal slope. We see that Say's Phoebe can be considered widespread if still rare in summer in the inland valleys of the coastal lowland.

Finally, Scott's Oriole occurs mainly along the mountain escarpment along the west edge of the Anza-Borrego Desert but also locally farther out into the desert. Occasional birds summer in mountain chaparral with abundant yuccas, as attested by reports from squares P22 and Q23 (the pair along the Noble Canyon Train in P22 has returned to the same spot for at least three years now). And there is a substantial isolated population in square C15, as part of the unusual extension of desert birds along the Riverside County line discovered.

--Ken Weaver

Wrenderings Archive | Bird Atlas Introduction