04/01/2011 06:05 pm ET | Updated Jun 01, 2011

Curious Observers Lend a Hand

Citizen scientists broaden the scope of climate-change research and public understanding

It's hard to think of a citizen-based science project that doesn't have a catchy name: Nature's Notebook, Christmas Bird Count, eBird, iNaturalist, Project BudBurst, to name a few. But don't let the cheery-sounding monikers fool you. These projects broaden the scope of scientific research and the collection and analysis of scientific data.

Because scientists can't be everywhere, information collected by trained volunteers is data that would not otherwise be easily accessible. "Having a continental-scale network of sentinel eyes on the landscape enhances the data traditionally available to scientists," says Sandra Henderson, Ph.D., the director of Project BudBurst at the National Ecological Observatory Network. A joint collaboration with the Chicago Botanic Garden, Project BudBurst is an online science campaign in which many citizen observers collect data about native plants.

Data recorded by these trained volunteer scientists support numerous peer-reviewed studies. For instance, data from Project BudBurst have extended the historical records of plant phenology -- the timing of natural events such as flowering. Dr. Kayri Havens, of the Chicago Botanic Garden, analyzed first-flowering dates for seven plant species common to the Chicago area. Adding to the historical data collected from the 1950s through 1994, the Project BudBurst data reflect observations made from 2007 through 2009. Havens' analysis shows significant changes in the timing of nature's blooms. The earliest-first-flower observations for forsythia, the bright yellow shrub that marks the beginning of spring, advanced 24 days from 1994 to 2009. Lilac bushes, too, advanced their flowering by 17 days over the same time period. These changes follow the pattern found by Dr. Terry Root and colleagues (published in Proceedings of the National Academy of Sciences) the average shift in the behavior -- phenology -- of 130 species from 1970 to 2000 means that spring is now arriving on average 10 days earlier in the Northern Hemisphere.

Observations of leaf growth and flowering show that the timing of these events has been affected by global warming. These changes have a cascading effect on ecosystems. Consider what's happening to birds, which are already adapting to climate change by shifting their ranges or altering their migration habits.

One long-term data record used by climate scientists in North America to study the early winter bird populations is the Christmas Bird Count, a program now in its 111th year. In 2010 participating citizen scientists counted 46 million birds. Analysis by Audubon scientists found that nearly 60 percent of 305 widely distributed bird species in North America have shifted their ranges northward by an average of 35 miles since 1966, with a few bird species moving several hundred miles.

Jake Weltzin, director of the U.S. National Phenology Network, says high-quality data collected by citizen observers can also help scientists use their resources more efficiently. "It is very difficult to cover entire regions to get information, especially in remote areas," said Weltzin. "That is one reason why scientists are supportive of citizen- or volunteer-generated data. They need more eyes and more sampling locations."

Weltzin points to one project, the Riverine Early Detectors program, designed to collect photographic images of invasive species. River guides and naturalists venture out into the water to take photos and help document the spread of aquatic invasive species.

One side benefit of citizens participating in science projects is education. When people look into nature and observe what is happening in their own back yards, their awareness of life-cycle events increases, as does their awareness of the effects of climate change.


La Sorte, F.A., and Thompson, F.R., III. (2007) Poleward shifts in winter ranges of North American birds. Ecology, 88, 1803-1812.

La Sorte, F.A., Lee, T.M., Wilman, H., and Jetz, W. (2009) Disparities between observed and predicted impacts of climate change on winter bird assemblages. Proceedings of the Royal Society B: Biological Sciences, 276, 3167-3174.

Root, T.L., D.P. MacMynowski, M.D. Mastrandrea, and S.H. Schneider. 2005. Human-modified temperatures induce species changes: Joint attribution. Proceedings of the National Academy of Sciences. 102: 7465-7469. Available at www.pnas.org_cgi_doi_10.1073_pnas.0502286102

Swink, F. and G. Wilhelm (1994). Plants of the Chicago Region, 4th ed., Indiana Academy of Science, Indianapolis, 921 pp.