Surveying for Purple Martins on Tejon Ranch
With the help of Tejon Ranch Conservancy, Audubon California, and Western Field Ornithologist the second annual Tejon Ranch purple martin survey was conducted the week of June 27-30, 2011. An enthusiastic group of 12 birders spent two days surveying Tunis, Winters, Middle, and Cordon Ridges. We found 21 nests and observed 81 purple martins. The first survey day was ideal, with clear skies, warm temperatures, a subtle breeze, and a total of 18 nests found. Last year, over a three day survey period a total of 23 nests were found. With the second day of surveying still to come the group was excited by the prospect of shattering last year’s total. But in the morning, as the groups drove to their respective ridges, the mood changed when it became apparent that all ridges were lost in the clouds. With zero visibility and cold temperatures the birders bundled up and the martins hunkered down in their cavities. Only 3 nests were found the second day, bringing the 2011 total to 21 nests. Even with the unfortunate weather valuable data was still collected with the help of these wonderful volunteers.
The characteristics of this year’s nest trees were consistent with those of last year’s trees. All nests were in large Valley Oaks at or near the tops of the ridges in fairly open settings. This year, however, the martins were in varying stages of nesting. Fledglings were observed at some nests, some pairs were feeding nestlings, and others were still incubating. A possible reason for this is that the prolonged unstable cold weather conditions that occurred throughout the spring delayed the arrival and nest initiation of part of the population.
Groups also tallied birds seen throughout the day. The group recorded a total of 57 species (link to pdf of species list), with 16 different species of cavity nesters. Like last year, we were stunned by the huge flocks (one numbering 100) of Lawerence’s Goldfinches.
We would like to thank all of our volunteers. Your help in collecting this data was invaluable. We would also like to thank Greg McMillan for once again providing us with amazing dinners and a warm fire in the morning and at night.
Tejon Ranch Purple Martin Expedition Participants