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Birders go to extreme lengths to see new birds: some will drive for hours to see a rarity; others rise before dawn to get some birding in before work; and still others plan their vacations around birds. It’s those traveling tendencies that interested one researcher who knew that scientists need to monitor populations of rare, hard-to-study birds, but don’t always have the time or funding to go find them themselves. What if they could use information gathered from traveling birders to monitor unique populations all over the world?

Carlos Camacho, a PhD student at the Doñana Biological Station in Seville, used the Peruvian Thick-knee (Burhinus superciliaris) as an example to show how using data submitted by traveling birders could work. He used Google searches and the popular birding trip report repository to compile all mentions of the bird in reports from 2000-2010. Birding trip reports usually include species names, locations, dates, times, maps, and photos, plus logistical information.

“There are vast armies of birdwatchers across the world,” says Stuart Butchart, the head of science at BirdLife International. “Many of them record information that can be hugely valuable for monitoring the state of the environment.”

Using that data, Camacho was able to estimate that populations of the shorebird were relatively steady in central Peru, but declined by as much as 90 percent in northern Chile. The in January in Animal Conservation.

So is the Peruvian Thick-knee population actually declining? It’s tough to say—the International Union for the Conservation of Nature lists the bird as a species of “Least Concern,” and there isn’t hard data to check Camacho’s estimate against. And there are other pitfalls. Compared with a systematic, scientific approach to population monitoring, birding trips tend to focus on particular spots with abundant birds, like protected areas. Tourists likely spend more time watching healthy populations of a particular bird, rather than noting that birds aren’t present elsewhere. In fact, birding reports almost never list a lack of sightings. Finally, estimates of the numbers of birds in a flock may also vary by counting technique or by the skills of the birder who writes up the report (though the researchers could take that into account when standardizing data).

Some may wonder how this method differs from using eBird, an online database where birders can upload what birds they did (and didn’t) see on a given day. Camacho thinks it’s more useful in specific cases because it would provide a more targeted analysis considering all data collected about specific rare populations, rather than just data submitted through the app. “Rare and endangered species are overrepresented in trip reports,” he says. Marshall Iliff, an eBird project leader at the Cornell Lab of Ornithology, says that the data in birding trip reports may indeed be “worth tapping in to” to get the broadest possible picture of how a certain species is doing, though he notes that eBird is already geared towards using birders’ data for scientific analyses, unlike birding trip reports.

Even if the method can’t be reliably used to adjust an endangered species’ status, it can be a helpful “alarm bell,” indicating that a species needs a closer look, Butchart says. The advantages of the method—it’s cheap, free, and can be used immediately—make it a low-risk option in a world with limited options. “I think that [this kind of data] may be the only information available for some species,” Camacho says.

In fact, it is a certain subset of species that stands to benefit most from this technique—those that are not overly threatened nor terribly common. And in those instances, the results might only yield better indications of where to focus further study.

So the next time you’re thinking about taking a big birding trip, go for it—and make sure you write up a trip report afterwards. Scientists—and the birds—may thank you.