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

WRENDERINGS
Progress Report
Spring 1999

As the San Diego County Bird Atlas' second winter season comes to a close, our winter database is growing rapidly. As it stands in mid-February, the winter database is already over 56,000 records, well over half again as large as it was from our first winter. We now have significant winter data from 404 of the 479 squares of the grid, or 84%. Broad coverage in winter after just two of the project's five years is critical because one of our basic goals for the winter phase is that data for each square cover at least three of the five years. Almost all of the squares from which we still have no winter data present difficult problems of access.

Of course, depth as well as breadth is essential to good coverage. Here we can see excellent progress as well. In 95 squares the goal of recording at least 90% of the number of species on the target list has been met, and in 53 the goal of at least 25 hours in the field has been met. Both these figures should increase rapidly as participants send in data at the end of the season. At the end of the project's third winter, the final criterion of data from at least three winters will be met in many squares and we will have the accomplishments of many participants to recognize.

It is a good sign that the 90% criterion is usually being met before the 25-hour criterion: this suggests the target lists are realistic and that 25 hours should give a thorough representation of each square's winter birds. The one area where this relationship fails to hold is in the bleakest parts of the Anza-Borrego Desert. Here it appears that the target lists were too optimistic. The suggested species may occur but so occasionally or in such low density that they cannot be found even by experienced observers in 25 hours or less. If you have one of these squares, please check with me.

Please note again that the 90% criterion is based on the number of species on the target list, not the individual species themselves. Almost everyone finds species not on the target list; in winter these count just as much toward the criterion as species on the list. In the breeding season, additional species count if it is possible they breed in the square.

Many participants are finding the 3-column winter incidental form useful. But please don't use it in place of the 12-column winter record form for your adopted squares. The winter record form has spaces for recording your hours and mileage, for all of which we want to credit you! If you use the 3-column form for any significant time in the field for other squares, please add your hours.

Even during the winter our breeding database continues to grow, up to 69,005 records, 2205 more than reported in the last issue of Wrenderings.

Thanks to those of you who send data electronically via the Museum's World Wide Web site; this helps spread the task of data entry. Nevertheless, we look forward to hearing from the rest of you now that the winter is over. Please send your original winter record form; we will copy it and return it to you as soon as we have entered the data. As always, sending your data in as soon as possible at the end of the season is essential to gauging our progress accurately and strategizing for the future.

--Philip Unitt

birdatlas@sdnhm.org

Redhead chick sketch by Nicole Perretta

Spring 1999 Wrenderings | Wrenderings Archive | Bird Atlas Introduction