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For the Birds

A new version of the Wisconsin Breeding Bird Atlas draws on the increasing power of citizen science

Slipping into a patch of woods in western Dane County, Jim Berkelman ignores the swarming mosquitoes and strains to sort through the early- morning chatter of warblers, robins and vireos and the nearby drum of a pileated woodpecker. “I’m hearing something I wouldn’t expect to hear,” says Berkelman, a lecturer in the Department of Forest and Wildlife Ecology at CALS and a volunteer contributor to the Wisconsin Breeding Bird Atlas II, a comprehensive, volunteer-powered survey of birds that nest in Wisconsin.

Experienced birders use their ears as much as their eyes to identify species, and Berkelman thinks he hears a northern parula, a small warbler that doesn’t typically nest this far south. Finding a bird, Berkelman explains, is only the start. The point of the Atlas, he notes, is to identify and map where birds in Wisconsin are courting, nesting, breeding and raising their broods.

To be sure of that, “atlasers,” as volunteer observers like Berkelman are called, must find tangible evidence that a species has actually taken up residence. A nest, of course, is the most obvious clue. But most birds are assiduously covert in their nesting and only conspicuous players like robins, herons, orioles, house wrens and bluebirds construct their nests in ways that make them easy to find and identify.

Other definitive hallmarks of breeding birds include observations of birds carrying nesting material or food for nestlings; distraction displays where birds seek to draw animals, other birds or humans away from a nest; and, of course, fledglings. Some bird species are fastidious as well and carry fecal matter away from occupied nests. Such an observation is also a telltale sign of breeding and can be used by an atlaser to confirm breeding activity and provide a new data point that science can ultimately draw on.

Following a rising wooded path to the top of a hill, Berkelman’s rounds on this warm June day encompass two different types of ecosystems: forest, and open fields and prairie. His block is designated as a “priority block,” a specified block within a six-block “quad” on a grid of more than 7,000 three-mile-by-three-mile blocks that covers Wisconsin. Within that grid are 1,175 priority blocks, each of which requires at least a year’s documentation of breeding birds within a five-year period to ensure that the state is uniformly surveyed for the new Atlas. In addition, there are 153 “specialty blocks” that have unique habitat, are of high conservation value or are of particular interest to ornithologists.

Today, Berkelman is recording his data the old-fashioned way: with pen and notebook. Later, he can plug his observations into Atlas eBird, an online checklist program that is a direct conduit to the database that is the bedrock of the Wisconsin Breeding Bird Atlas.

Data, of course, are the raw material of science. Astronomers gather it by measuring and parsing starlight. Molecular biologists get data by plumbing the sequence of the chemical base pairs that make up a gene or genome. Meteorologists numerically dissect the many variables of weather—temperature, precipitation, wind, clouds.

To be sure, most data collection is a laborious and numbing process—the antithesis of the eureka moment. Harvesting data can be very expensive, too, as the tools of modern science have become bigger, more complex and more powerful in their ability to see farther or smaller, drill deeper, or accelerate particles to higher energies. Indeed, much of what we hear about modern scientific discovery rests on the pillars of sophisticated technology. Think of the Hubble Space Telescope, the Large Hadron Collider, the IceCube Neutrino Observatory and the Human Genome Project as just a few examples.

But while technology is taking science to new heights, it’s also giving a boost to the age-old methods of data gathering like the ones Berkelman uses in his efforts to document the presence of breeding birds. The Internet and personal computing technology are being used like never before to crowd-source traditional observational data collected by a growing cadre of citizen scientists. Groups of people or individuals armed with laptops and app-laden smartphones are collectively logging everything from trash in the ocean and flying ants to cosmic rays and precipitation, giving working scientists access to oceans of new data and the revelations that come from subsequent analysis and interpretation.

In the realm of ecology, citizen science has gained a new standing as researchers have tapped into the potential of an interested public. Citizen science projects, mapping things like the presence and behaviors of bumblebees, manta rays, butterflies and bats, have fueled dozens of published studies.

It’s proven to be a powerful resource for Ben Zuckerberg, a professor of forest and wildlife ecology at CALS. North American birds and their distribution on a changing landscape are a primary focus of his research, a significant portion of which depends on data gathered by volunteer observers.

For instance, Zuckerberg and post-doctoral fellow Karine Princé drew on citizen science data to tell us that the cast of characters we see at our bird feeders in the winter is shifting, most likely due to climate change. Their study of wintering songbirds shows that some species, once rare during the Wisconsin winter, are shifting their ranges north, remaking the resident communities of birds that visit our backyard feeders.

The conclusions of the study rested on two decades of data gathered by thousands of citizen scientists through the Cornell University Laboratory of Ornithology’s Project Feederwatch.

“Birds have always been important environmental indicators,” Zuckerberg explains. Rapidly declining songbird populations in the 1950s and 1960s, he notes, were used to help ascertain the consequences of widespread use of the chemical insecticide DDT, which was subsequently banned, first in Wisconsin and then nationally.

The DDT story was famously informed by the unintended involvement of ordinary citizens who gathered baseline data in the form of bird eggs. In the 19th century, collecting bird eggs was a widespread hobby, an artifact of the Victorian obsession with the natural world. Many collections ended up in museums where, decades later, CALS ornithologist Joseph Hickey and his students used them to document the thinning of eggshells subsequent to the widespread introduction of DDT into the environment in the 1940s and ’50s.

Today the contributions of citizen scientists tend to be more directed, and the advent of personal computers and smartphones, in particular, are making participation easier, more immediate and more effective. And a prime example of that trend is the Wisconsin Breeding Bird Atlas, a collaborative project by the Wisconsin Department of Natural Resources (DNR), the Wisconsin Society for Ornithology, the Wisconsin Bird Conservation Initiative and the Western Great Lakes Bird and Bat Observatory.

This year, the group launched a second iteration of the Atlas. Zuckerberg and other scientists are working with Atlas coordinators and waiting in anticipation of a flood of new data from the project, which recruits volunteers statewide to survey thousands of designated blocks over a five-year period for evidence of breeding birds.

The first Wisconsin Breeding Bird Atlas featured data collected by nearly 1,600 volunteers between 1995 and 2000. As its name implies, the Atlas is a survey that documents the distribution and abundance of birds breeding in Wisconsin. It provides critical baseline information about bird species that live in our state and is an important benchmark in terms of assessing potential changes in bird populations over time due to things like habitat loss and climate change. It also helps document avian diversity, the state of endangered and rare bird species, and habitat needs in Wisconsin.

Such data, explains Zuckerberg, help scientists make sense of a world that involves players ranging from microbes to plants and animals, including birds. There are so many moving parts that capturing a wide snapshot of what exists where at a given point in time can give scientists insightful information about the dynamics, nuances and health of an ecosystem.

“Ecology is necessarily a messy endeavor,” Zuckerberg observes. “But at certain scales, it all becomes very clear.”

Drawing on things like Breeding Bird Atlas data, Zuckerberg and other scientists can get at the scales that matter: geography and time. As the Wisconsin Breeding Bird Atlas II effort gets under way, ecologists are laying the groundwork for analyzing the data by formulating hypotheses and ideas about what the data might show and how it will compare to data in the first iteration of the Atlas, which, according to the Wisconsin Society of Ornithology, “represented the largest coordinated field effort in the history of Wisconsin ornithology.”

Data collection for the Wisconsin Breeding Bird Atlas II began in 2015 and runs through 2019. In September the DNR released findings for the first Atlas season. Volunteers submitted nearly 24,000 checklists documenting the location and breeding activity of 229 species of birds. These early data show that wild turkeys are on the move, now populating nearly every corner of our state. And eight species of birds new to the Wisconsin breeding landscape since the last survey—including the iconic whooping crane—have cropped up in the new Atlas data.

“The stories that come out of the data are so robust,” Zuckerberg says. “We go in with our ideas of what we’re going to uncover, and some of the patterns just jump out at us.”

The major advantage of the Wisconsin Breeding Bird Atlas, according to noted ornithologist Stan Temple, a CALS emeritus professor in forest and wildlife ecology, is that it documents the relationship between birds and the places they require to successfully reproduce. “Habitat affinity is where the Atlas works best,” Temple explains.

Temple cites other long-standing citizen science efforts to document birds. The North American Breeding Bird Survey was officially launched in 1966. Conducted during the breeding season, volunteers traverse by car more than 3,700 randomly selected 24.5-mile road transects in the United States and Canada. Stopping every half-mile, volunteers document every bird seen or heard in a three-minute span before moving to the next observing station. The North American Breeding Bird Survey, Temple argues, is the gold standard for measuring population trends among birds.

A more recent citizen science effort—one that capitalizes on personal computing technology and helps inform the Wisconsin Breeding Bird Atlas—is the aforementioned eBird. Taking old-fashioned pen and paper checklists into the digital age, eBird is an online checklist linked to a central database. Used by amateur and professional birders, eBird logs millions of bird observations worldwide in any given month through a simple and intuitive web interface. The Wisconsin Breeding Bird Atlas II is the first state Atlas effort to employ it.

“We’re in the information age now,” explains Nick Anich, the Wisconsin DNR Breeding Bird Atlas coordinator. “We have eBird. We’re excited to use this new system. The developers have put an awful lot of effort into the checklist input, and they just launched the maps function. And the data update at least every 24 hours, so we can see things in real time.”

But can the information gathered by armies of citizen scientists be trusted? Can it help researchers predict the future of Wisconsin’s environment? How is it validated? Can scientists get over any qualms they might have about data collected beyond the strict parameters of controlled experiments and expert observation?

Zuckerberg, who has published on the use and value of crowd-sourced data, believes that many scientists are coming around to the idea that the data indeed represent an accurate picture of the natural world. “There has always been some skepticism about it in ecology. But studies show it is valuable data that are relatively accurate for picking up ecological patterns and processes,” Zuckerberg says.

“There are entire subfields of ecology dependent on these data. Theories in macroecology and how species respond to widespread environmental changes, such as pollution or climate change, for example,” Zuckerberg observes, referencing the study of relationships between living organisms and their environments at large spatial scales. “We wouldn’t be able to do anything like that without citizen science.”

That kind of insight is essential, Zuckerberg stresses, as broad-scale environmental change due to pollution, deforestation, reforestation and climate change will have significant and possibly lasting effects on birds in many different types of ecosystems.

According to Temple, the power of citizen science lies in the sheer numbers of observers. As a new CALS faculty member in 1976, Temple launched the Wisconsin Checklist Project. “The Wisconsin Checklist Project did in the predigital age what eBird does now,” Temple explains. “It is a rigorous way of engaging lots of bird-watchers in a very systematic way.”

For the most part, Temple says, the data are trustworthy. “Bird-watchers are used to keeping records, so you’re not asking them to do anything that already isn’t part of the culture. Mistakes in observing and recording happen, but it is safe to say those few errors become insignificant noise in comparison to the strength of the signal: the overwhelming number of accurate observations.”

For atlasers like Florence Edwards-Miller, a 31-year-old communications specialist from Madison, the chance to go into the field and gather data blends neatly with her deep-felt appreciation of the natural world.

Trekking through the prime birding habitat of Madison’s Nine Springs E-way on a rainy midsummer morning, Edwards-Miller is on a mission. An experienced birder, she knows she can confirm any number of breeding birds that use the settling ponds of Madison’s Metropolitan Sewerage District to raise their broods. And she is eager to contribute those little bits of data to the Wisconsin Breeding Bird Atlas effort.

“You can’t make good decisions unless you know what’s out there,” says Edwards-Miller. “I believe in science. I believe in the importance of the data.”

In a little more than an hour, she confirms the presence of breeding mallards, Canada geese and red-winged blackbirds—all pedestrian wetland species—by noting offspring and, in the case of the blackbirds, a cantankerous distraction display.

It takes a little longer to find the killdeer fledglings, but at the end of our circuit around the pond, there they are: little puffballs on stilts trailing behind their foraging parents. It’s a beautiful sight. And another valuable data point for the Wisconsin Breeding Bird Atlas.