Allison Shultz replicated bird surveys done on the Berkeley campus in the early and mid-1900s.
Credit: Allison Shultz.
This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.
Berkeley undergrad Allison Shultz was in Lassen Volcanic National Park, counting birds for a conservation study known as the Grinnell Resurvey Project, when a colleague mentioned a similar count done almost 100 years earlier on the Berkeley campus.
Supposedly, he said, a woman scientist in the early 20th century had recorded meticulous observations about Berkeley's birds, as a basis for a long-term study.
Shultz was intrigued, and decided to look on campus for the notebooks from that study.
The Museum of Vertebrate Zoology at Berkeley, where Shultz studied and volunteered, had plenty of archived field notes. She dug around, and eventually found a big envelope in the back of a cabinet. It was stuffed with small notebooks.
"It was thrilling when I found them," she says. "I ran around the whole museum, telling everyone."
The notes, "basically like an Excel spreadsheet," had belonged to Margaret Wythe, who worked with none other than Joseph Grinnell. It's rare to have detailed, consistent, century-old field data — the kind that help scientists understand a species' decline or emergence in a given area over time. More often, scientists use new or recent data — because that's what they have — to study ecosystem change and predict the possible effects of such factors such as climate change and urban sprawl.
Wythe had the future in mind when she recorded her observations between 1913 and 1927. In one paper, she wondered, "As plans for a greater university progress … and the environment of campus birds undergoes further changes, what will then be the representation of the bird population of the lower campus?"
From Wythe to Shultz
Shultz replicated Wythe's 1913-1918 surveys as well as a follow-up 1938 survey done by Thomas Rodgers and grad student Charles Sibley. She did as much research as she could, especially on Wythe, who began her career at the MVZ, working as Grinnell's assistant for 35 cents per hour. Eventually Wythe earned the title of Assistant Curator of Birds and co-authored with Grinnell the Directory to the bird-life of the San Francisco Bay region. Says Shultz: "I felt a sort of affinity, especially looking at her field notes, which she wrote by hand."
Shultz did her bird watching for 10 days every month over six months, in one-hour stretches between classes — in the morning, at midday and just before sunset. She laid out routes similar to those used by Sibley and Rodgers. At least initially, standing there with binoculars, notebook and rangefinder, she did get some curious looks. But, people are used to seeing strange things on the Berkeley campus, she says.
The campus birds, for their part, are used to lots of people. Often, Shultz could get quite close to her study subjects. However, noise was a problem — groundskeepers' lawnmowers, people talking and, especially on weekends, dogs barking. "The disturbances the birds had to deal with all the time made for difficult field conditions," she says. Plus, "I don't know if it's because I was just standing there and look like a friendly person, but people were always asking me for directions and just talking to me in general."
To record her observations, Shultz used the method Grinnell established, a protocol still practiced by biologists today. It involves recording time and place consistently as well as underlining certain data to make for easy scanning later on.
Shultz also used the same field techniques as the earlier scientists, except that, to enhance her chances of spotting birds, she used point counts rather than line transects — meaning she observed from one spot rather than continuously moving. The only new technology? The rangefinder. "In terms of bird surveying, things haven't changed too much over course of century," she explains.
Species Turnover, Not Loss
Once she'd finished the field research, Shultz took advanced statistics courses to master the skills she'd need to make full sense of the data. Then she analyzed her data with Morgan Tingley, who would be a coauthor on the resulting paper. From a conservation perspective, the results were encouraging.
Shultz discovered that the number of bird species — i.e, the species richness — and the ecosystem roles different birds play — i.e, the functional diversity — hadn't changed over the last 100 years. In fact, the number of different species increased.
But which species were on campus did change, reflecting the changed landscape at Berkeley — namely more and bigger buildings (22 in 1913, 31 in 2006), less woodland, tall grasses and chaparral and more lawn and ornamental shrubbery. In 1913, Song, White-Crowned and Golden-Crowned sparrows, as well as wrentits, were common in the brush, as were grassland species such as the Western Meadowlark.
Shultz says the species she was most surprised to spot was the Varied Thrush. "The Varied Thrush is a shy forest bird," she said, "so I was pretty surprised to find them on campus." But they tend to crop up at certain times, so their appearance wasn't a total mystery, she says.
All in all, Shultz found 48 species in the 84 acres she surveyed. Wythe had counted 44 species in 1913-18 and Sibley/Rodgers counted 46 in 1938-39. These results suggest that "by landscaping native habitats, native bird communities can persist through time or be restored, even in developed areas," Shultz says.
In May 2012, Shultz, Tingley and UC-Berkeley professor Rauri Bowie published their study in The Condor (which is where Rodgers and Sibley published their findings in 1940). The three authors concluded that Berkeley's avian history offers a larger lesson. "The greatest potential for urban biodiversity conservation may be . . . in the prescribed management of green spaces to harbor the specific elements of diversity most at risk. It is time for urban green spaces to be thought of not only a hospice for diversity, but also as potential nurseries."
Since doing the study in 2006 and earning her bachelor's in integrative biology in 2007, Shultz has gone on to earn a Master's degree in biology from San Diego State University and enroll as a Ph.D. student in organismic and evolutionary biology at Harvard. She participated in a 4-week specimen-collecting trip to Eastern Mongolia in summer 2012. She currently is using RAD-tag sequencing techniques to analyze the phylogeography of the House Finch, which means she is studying, thinking about and modeling scenarios related to the origin and dispersal of several introduced populations of the House Finch.
She hopes the Berkeley study will inspire other students to search their university collections for data from studies they can replicate.
"I loved having an excuse to just go and pay attention and be out in nature, to really open your eyes in that place," she says.
"Usually when you're on campus walking to class, you're like, 'Oh, I need to get to next building.' But you realize when you stop and pay attention that there is all this interesting life around you, organisms that are there that you just never noticed before.
"And once you turn on that side of you, you can't turn it off. Even at Harvard now, I can't walk around and ignore the birds. I'm constantly looking."
Editor's Note: The researchers depicted in Behind the Scenes articles have been supported by the National Science Foundation, the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Behind the Scenes Archive.