Field research at Jasper Ridge

Vanishing birds

Bill Anderegg

Bill Anderegg, a 2008 Human Biology graduate, did his honors thesis on the precarious bird population of Jasper Ridge.
Photo: Nona Chiariello

The checkerspot butterflies are not the only species to go missing.

Bill Love Anderegg, another ’08 graduate, did his honors thesis on wetland bird populations at Jasper Ridge. He repeated a survey conducted in 1971 that showed that Jasper Ridge was home to the highest known breeding density of land birds in the United States. Thirty-five years later, Anderegg tested the effects of development and climate change.

He found “significant” declines in avian diversity. Some species were below Anderegg’s detection threshold, and one has nearly disappeared. Other species that don’t seem to mind humans have increased. His honors thesis, which earned him a Firestone Medal for Excellence in Undergraduate Research, concluded that more habitat protection and better development planning along streams is imperative.

Anderegg, who is entering Stanford’s biology doctoral program, never intended to be a scientist. He started off as an English major, one who particularly loved creative writing. A semester abroad made him rethink his priorities, and he returned from Spain a human biology major.

“My interest in multidisciplinarity grew out of the thesis,” he said last spring, a few days before graduation and then a summer trip to Africa. “I expected to just be doing birds. But more and more I was looking into human interactions. I found myself talking to old birders, looking at their data. I asked them, how did you get your data, how did you count the birds? One old guy—he did his dissertation with Ehrlich in the sixties, I think—sent me his old field notes.”

As with the longitudinal study of butterflies, the ornithology work extended far beyond the birds. Anderegg’s adviser was Terry Root, a biologist, expert on global warming and another IPCC author. “So that led me to climate change,” Anderegg said. "And then Trevor Hebert," the GIS manager for Jasper Ridge, "gave me aerial photos and GIS data, so I could track changes in land use and map it against bird habitation.”