WRENDERINGS Progress Report Summer 1999

The San Diego Bird Atlas' second winter season was a great advance over the first. Our winter database is at 79,445 records, meaning the amount of winter data recorded in the second season was about 24% greater than in the first. Even more impressive is our geographic coverage, 427 of 479 squares, 89% of the total and a huge advance over the 329 covered during the first winter.

Because one of our threshold criteria is that the winter data from each square be spread over at least three winters, the winter threshold goal cannot have been met yet in any square. But the goal is already within easy reach in many squares. The criterion that 90% of the number of species on the target list be recorded has already been met in 175 squares (36.5%), and the criterion that our observers devote at least 25 hours to covering the square has already been met in 88 squares (18.4%). Both of these criteria have been met in 74 squares (15.4%), which therefore need just a single field trip in a subsequent year for their threshold to be cleared.

Now that we are in our third of five breeding seasons our breeding-season database is growing rapidly again, over 80,000 records. We now have significant data from 421 squares (88% of the total). The threshold goal, with 50% of the number of species on the target list confirmed breeding, has been cleared in eight more squares, thanks to the efforts of

Furthermore, the reduction of the target lists for the desert squares lacking oases now means the threshold has been cleared, with 50% of the target list confirmed, by

The most ambitious threshold has now been cleared in 70 squares (14.6%). In 35 additional squares the threshold has been reached with all criteria met and between 33% and 50% of the number of species on the target list confirmed. Participants reaching this level are

Note that in some cases the criteria for the threshold are met by the combined efforts of observers working independently. If it seems that our progress is slow, please note also that at least 50% of the target list has been confirmed in 15 more squares that have only the 25-hour criterion still to be met and 33% of the target list has been confirmed in 83 more squares beyond that. I am sure that at our next wingding, in September, we will have many new threshold-clearers to recognize.

With our field assistants made possible by our grant from CalTrans, we tackled 47 un- or poorly covered squares, sometimes revisiting those targeted on blockbuster weekends. Early in the spring we concentrated in the Anza-Borrego Desert, with Paul Jorgensen's help both in the field and getting us to some of the most remote parts of the park. And thanks to Ann and Richard Payne for so graciously putting us up at their home in Borrego Springs. As the season progressed, our effort shifted upslope.

Philip Unitt

birdatlas@sdnhm.org

Redhead chick sketch by Nicole Perretta