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The Devoted People behind Big Data in National Parks

Citizen science volunteers collect massive amounts of crucial scientific information. They gather it from sources as varied as oceans, mountainsides, and historic archives. Smart new tools are making their contributions even more powerful.

Two smiling women stand in front of a national park sign — Hutchins (left) and White
Image credit: NPS

Linda White and Vivian Hutchins are trail runners and hikers in Saguaro National Park. They became close friends after sharing a moment over a night-blooming cereus cactus flower in 2014.

“They are so mysterious and beautiful,” said White. The night-blooming cereus is an elusive cactus with large white flowers, many of which bloom all at once during the hottest part of the Sonoran Desert summer. On one early morning run, White and Hutchins found 16 individuals of this plant, which scientists once thought to be rare. “It was misty and foggy,” Hutchins recalls. “The plants were luminescent. We were giddy and laughing as we found them.”

Three white flowers with many petals and yellow stamens grow against a backdrop of brown vegetation — Night-blooming cereus flowers
Image credit: NPS / Vivian Hutchins

White was already a park volunteer, so she shared their observations with park biologists. In the years since, White and Hutchins have continued to help the park map and monitor this long-lived but poorly understood plant.

White and Hutchins aren’t biologists themselves—White is a retired social worker, and Hutchins is a visual artist. But they love giving back to the park while hiking and running. They’re part of a growing number of citizen scientists who collect data during their visits to national parks and other public lands. Their contributions to understanding and preserving our natural and cultural resources are more critical than many realize.

A woman in a ball cap looks at several white flowers in an arid landscape — Image credit: NPS / Linda White

Tapping into Enthusiasm

Addressing the many environmental problems of America’s public lands and waters requires accurate data—and sometimes really big data sets—that only science can give us. Yet the need for this kind of information far exceeds the capacity of scientists and staff to collect it. More than 300 million people visit national parks every year. If they became citizen scientists, their help could make a real difference. But how?

In the world of strategic communication, incentives are key—think free stickers, or the buzz of praise from your fitness app.

To answer that question, let’s first consider what inspires people to help. In the world of strategic communication, incentives are key—think free stickers, or the buzz of praise from your fitness app when you’ve achieved a workout goal. Reducing barriers to participation, called “entry” in the communication business, is also key; for example, allowing people to make an online purchase with only a few simple clicks. In their book Nudge, Richard H. Thaler and Cass R. Sunstein describe nudges as small actions that make it easier to do something you know is good for you, like when your smartphone reminds you to take a stretch break. Small actions are most effective when they’re easy—like when you can simply turn on a ranger podcast or run into a friendly ranger on the trail.

A diverse group of young people with a park ranger in uniform — Image credit: NPS

Learning from Park Interpreters

National Park Service interpretive rangers—interpreters—are familiar with these approaches. For example, they provide Junior Ranger badges as incentives and ask low-stakes, easy-to-answer questions that encourage visitors to share their experiences and stay for more. They reduce barriers to entry by moving beyond traditional ranger-led talks that may engage only a small percentage of visitors. Interpreters reach out to wider audiences of family groups, hikers, rock-climbers and others, especially underserved communities who may not always feel welcome in parks. All these individuals have the capacity to help scientists further understanding of the complex, difficult problems in our national parks.

Park scientists can follow interpreters’ lead by providing visitors with incentives to participate in citizen science projects and recruiting a wide spectrum of visitors.

Park scientists can follow interpreters’ lead by providing visitors with incentives to participate in citizen science projects and recruiting a wide spectrum of visitors. We can gain insight about how to do this by asking a few simple questions:

Who are our visitors?
What do they do in parks?
What unique scientific contributions might visitors provide?
What motivates them?
How can we provide appealing incentives and reduce barriers to their participation?
How can we use citizen science (sometimes referred to as “community science,” although that’s a different type of engagement ) to actually help us learn what we need to know?

We can answer the first five questions directly. For the last one, we can look to examples from parks and partner organizations, who are addressing these questions in creative ways.

Long line of visitors waits to board park shuttle. — Image credit: NPS / Jonathan Shafer

Who Are National Park Visitors, What Do They Do, and How Can They Contribute?

You may think a typical national park visitor is someone on vacation who stays briefly and takes in park highlights like the Old Faithful geyser at Yellowstone. But actual visitors and their experiences vary greatly. We can categorize visitors in many ways, from demographics to group size. But for understanding how they could contribute to citizen science, let’s group them by what they tend to do in parks.

Casual visitors take in the park on quick visits like driving tours. Some of these are regular visitors, usually local residents, who come to walk or enjoy a picnic. Naturalists visit once or frequently, and are driven by their deep interest in birds, reptiles, plants, or other things in nature. Activity-driven visitors engage in recreation they are passionate about, such as rafting, rock climbing, backpacking, or fishing. Experts are people like the local "super volunteers" who serve many parks productively and long-term. Online visitors can connect with a park through social media even when they aren’t there in person.

We can gain a practical sense of what park visitors do by the “things to do” lists on National Park Service websites.

We can gain a practical sense of what park visitors do by the “things to do” lists on National Park Service websites. For example, Arches National Park recommends guided walks and auto tours for casual visitors, and hiking, backpacking, canyoneering, rock climbing, and horseback riding for longer-term visitors. Mesa Verde National Park recommends ranger tours but also stargazing and cultural dances. At Weir Farm National Historical Park in Connecticut, things to do include creating art.

A man teaches a woman how to weave a sweetgrass basket. — Making sweetgrass baskets during the 2023 Gullah Geechee Heritage Celebration at Reconstruction Era National Historical Park in Beaufort, South Carolina.
Image credit: NPS / Elena De Marco

What Motivates Visitors, and How Do We Make It Easy for Them to Participate?

Once again, scientists wanting to know how to engage with these very different types of visitors and what motivates them to become citizen scientists can learn from interpreters. How do interpreters reach different visitors? A few examples might give us some clues. Weir Farm interpreters offer art programs and a visitor center, but also go on walking patrols where they talk to visitors. Mesa Verde gives ranger-led programs, but visitors who prefer to be on their own can download and listen to audio tours and podcasts.

Audio tours might seem a less personal way of experiencing the park. Yet interpreter Spencer Burke said they can be more powerful than in-person tours “because of how they intimately connect with visitors.” For example, the Mesa Top Loop audio tour features the voice of TJ Atsye, who is Laguna Pueblo and a direct descendent of the people who once lived in Mesa Verde. Her story shares a perspective park visitors might not otherwise encounter.

We should consider a broad range of outreach avenues to recruit different types of visitors for participating in citizen science projects.

In Saguaro National Park, where I work, casual visitors may attend a ranger program, but thru-hikers on the 800-mile Arizona National Scenic Trail may converse with an interpretive ranger far from the visitor center. Local residents often sign up for Art in the Park camps and holiday programs. For online visitors, Saguaro’s Instagram page has one of the largest followings in Tucson, featuring popular events such as "Freddy Fridays" with ranger Freddy Fernandez-Ramirez. These examples tell us we should consider a broad range of outreach avenues to recruit different types of visitors for participating in citizen science projects.

Reducing barriers to participation is particularly relevant for recruiting visitors as citizen scientists in national parks. Most visitors have a positive view of national parks and may really want to help; we just need to point them in the right direction. Casual visitors may need a low barrier for entry, something they can do easily and quickly. Regulars are similar but might collect data on every visit if they feel their efforts are appreciated.

Activity-driven visitors will collect hard-to-get data in remote places if it can be done while they’re rock climbing or fishing. With good guidance, expert visitors can do great science in exchange for a little effort by park staff. With the help of innovative tech tools, many parks and natural areas are engaging these different types of citizen scientists in creative ways. Let’s look at some of those tools and how they’re being put to use in parks to gather real scientific data and address real-world problems.

A man bending over to examine an instrument held by a woman. Both are standing in a stream. — "Superhero" volunteer Chuck Perger (left), a citizen science hydrologist at Saguaro National Park, collecting stream gauge data in Rincon Creek with National Park Service hydrologist Colleen Filippoine.
Image credit: NPS

How Can Citizen Science Help Us Learn What We Need to Know? Some Real-World Examples.

Thousands of Casual Observations Paint a Powerful Picture

Park managers need evidence of how resources are changing. Repeat photography is one way to get it, and even very casual visitors can help. The simple to use app, Chronolog, allows visitors to rest their phones on a physical platform next to a road or trail, snap a photo, and email it to a site where it’s instantly uploaded and displayed.

At Tonto National Monument in Arizona, visitor photos help track the ecological response from the 2019 Woodbury Fire along a popular trail. At Indiana Dunes National Park, they document the progress of beach restoration. At Saguaro, Chronolog photos provide the only record of snowpack in high elevation forests where there’s no winter staff or snow station.

Top image
Chronolog photo of pine forest in Saguaro National Park in winter (February 25, 2023). Slide the arrow up and down to see the full photo in each season.
Credit: NPS

Bottom image
Chronolog photo of pine forest in Saguaro National Park in summer (August 18, 2021). Photos taken by Arizona Trail hikers at this remote station are the only documentation of changing snow conditions in the Rincon Mountains.
Credit: NPS

In Mount Rainier National Park, scientists looked at tens of thousands of photos of subalpine and alpine meadows uploaded to Flickr from 2009 to 2015. They used these images to capture the relationship between park visitation and climate-change driven shifts in plant communities that “could fundamentally alter visitor experiences.”

The occasional observations of thousands of visitors can produce huge amounts of data impossible for park staff and scientists to obtain otherwise.

Beyond repeat photography, the occasional observations of thousands of visitors add up. They can produce huge amounts of data impossible for park staff and scientists to obtain otherwise. In the Otter Spotter program in Great Smoky Mountains National Park, visitors use iNaturalist to document the distribution and abundance of river otters, which were introduced into their former range in 1986.According to Appalachian Highlands Science Learning Center coordinator Paul Super, monitoring otters is helpful for managing the fishery and for communicating with anglers about these charismatic mammals. Super said it’s always better “if you can generate the data on demand.”

otter swimming — Image credit: NPS / Eric Johnston

The park’s iNaturalist Snapit & Mapit project encourages visitors to contribute photos of plants and animals to the Atlas of the Smokies and help monitor over 100 of “Smokies Most Wanted” species. Park managers and scientists use this atlas to answer questions about patterns in biodiversity.

At Rocky Mountain National Park, visitors to Lily Lake can walk a phenology loop trail and upload the answers to questions at different stops using the ArcGIS app, Survey123. The park uses the data to determine shifts in the seasonal timing of biological events like animal migration or when leaves change color. Also in that park, a partner organization allows visitors to upload observations of pikas and pika signs like scat or tracks through the Pika Patrol app.

Monarch butterflies, some of North America’s most beloved plant pollinators, are under threat. To help them, Grand Canyon National Park partners with the Western Monarch Milkweed Mapper project. This project enables visitors to report sightings of monarch butterflies and their host milkweed plants using an online mapping tool. Indiana Dunes National Park is a site for a similar program with the Monarch Joint Venture.

At Saguaro, our Gila monster repeat photography project encourages visitors to collect data on this rare, charismatic, and long-lived reptile.

At Saguaro, our Gila monster repeat photography project encourages visitors—especially regular, local visitors—to collect data on this rare, charismatic, and long-lived reptile. Gila monsters have a colorful beaded skin pattern that doesn’t change over the animal’s adult life. This allows us to identify individuals and study their territory sizes, longevity, and activity patterns.

Colorful lizard with raised reddish and black markings — Image credit: NPS

Many parks and their partners participate in these simple, often app-based, citizen science programs that focus on specific regional or national issues. What these programs have in common are low barriers to entry. They work best when collecting data is quick and easy, like taking a photo that visitors can upload or email with a few clicks while on their walk or drive.

I, Naturalist

A group of visitors with spotting scopes — Image credit: NPS / Jacob W. Frank

Naturalists are a special type of visitor whom national parks attract in great numbers. That’s demonstrated by the millions of unsolicited observations in parks appearing on iNaturalist, eBird, and other such mobile apps. Parks can create projects that tap into the keen enthusiasm of naturalist visitors by using these platforms.

Acadia National Park works closely with its partner, the Schoodic Institute, on a menu of iNaturalist projects like bioblitzes and early invasive species detection. Thousands of people participate in citizen science at the park each year. And the main iNaturalist project has more than 50,000 observations and active campaigns to monitor rapid changes in sea star populations and invasive plants.

One of Saguaro’s iNaturalist projects encourages hikers interested in botany to record their observations of high-elevation, moisture-loving plants that may be vulnerable to climate change. According to Saguaro botanist Dan Beckman, the beauty of iNaturalist is the way it opens a direct line of communication to both casual and dedicated plant lovers.

View from above a tall, flowering saguaro cactus where a man is looking up holding an instrument — Citizen science volunteer collecting data on saguaro flowering phenology at Saguaro National Park.
Image credit: NPS

Professional botanists have surveyed the park for over 130 years. But in the last five years, volunteers have reported at least nine previously undocumented plant species, which park staff confirmed in follow-up visits. Beckman noted, “It’s really about building community—virtual and in-person—where we can engage and communicate regularly.” He said iNaturalist allows “a multi-pronged approach to crowdsourcing and facilitating scientific discoveries.”

A critical step with naturalist observations is giving volunteers access to the study results, a key incentive for their participation.

A critical step with naturalist observations is giving volunteers access to the study results, a key incentive for their participation. Kyle Lima, an ecologist with the Schoodic Institute, told us it’s important that the project data reach three important audiences: resource managers at Acadia National Park, the citizen scientists themselves, and the public. To meet the needs of these audiences, Lima and his colleagues have developed automated systems for analyzing and communicating the observations.

As a result, park managers can quickly learn about new sightings of at-risk or rare species. Immediate notifications about pests also allow them to respond rapidly and strategically to things like hemlock woolly adelgid infestations. Visitors to the Acadia National Park Rockefeller Welcome Center on the Schoodic Peninsula can use an interactive kiosk to learn about which species of plants and animals are being observed on iNaturalist and eBird in real time, encouraging visitors to send in their own photos.

A “Wonderful” Mix of Hiking and Science

A hiker with a backpack holds their hiking boots above the water. The water is thigh high. — Image credit: NPS / Gin Majka

Biologists are often concerned about threats to wildlife in remote alpine and subalpine areas but are challenged by the time and effort required to reach these areas. That’s where backpackers and thru-hikers can help. The High Country Citizen Science Project trains Glacier National Park’s backpacking visitors to identify and classify mountain goats by age and sex.

To “hike and to be of service to science is almost more wonderful than I can wrap my mind around.”

The backpackers do one-hour surveys at designated sites. The data they collected have proven very effective for estimating goat abundance and tracking population and distribution changes over time. One participant said that he would be hiking anyway, but to “hike and to be of service to science is almost more wonderful than I can wrap my mind around.”

Large black and white birds swimming in a deep blue lake — Image credit: NPS

Glacier also monitors much of its common loon population in a large and well-established program with volunteer hikers. The data they collect provide a scientific basis for protecting this bird, which is a Montana State “species of concern.” And Olympic National Park has a program where hikers can monitor marmots and view illustrated annual results.

Backpacking naturalists in California collect data to help land managers make decisions about solar and wind energy farms.

Some of the most helpful citizen science programs are where volunteers who love to hike into remote areas also possess strong naturalist skills. In the rugged Mojave and Colorado desert areas of southern California, an avicaching project led by Sonoran Joint Venture recruited backpacking volunteer naturalists to collect data. This information is intended to help land managers make decisions about alternative energy projects, particularly solar and wind energy farms. Several land trusts in New England have used data collected from remote sites by backpackers through the Mountain Birdwatch project to identify and purchase high priority bird habitat for conservation.

The Global Reach of Aquatic Volunteers

Two girls holding a trash bag walking on the ocean beach — Image credit: NPS / Kirke Wrench

A significant number of recreational boaters, canoeists, river rafters, and divers visit national parks. At Buck Island Reef National Monument in the U.S. Virgin Islands, volunteer divers help fight deadly coral diseases. As citizen scientists, recreational anglers collect scientific data on behalf of the National Oceanic and Atmospheric Administration (NOAA). They’ve helped remove certain types of rockfish from the endangered species list and uncover how tiger sharks respond to warming ocean temperatures.

Boaters, canoeists, and beach-goers help track the global movements of ocean trash.

Boaters, canoeists, and beach-goers can use Debris Tracker and other apps to record trash along coastlines and in waterways and inland communities. Their data are used to help track the global movements of ocean trash. NOAA partners with Channel Islands National Park and others to recruit citizen scientists to help monitor endangered whales and reduce whale strikes and entanglements through the Whale Alert – West Coast project.

The scope of the citizen science data set far exceeded what professional scientists could have collected on their own.

In and near Grand Canyon National Park, hundreds of river guides and their guests were active participants in a 2012–2014 U.S. Geological Survey project. While camping along the Colorado River, these citizen scientists used light traps to study the adult stages of aquatic insects. They collected more than 2,500 samples, which helped researchers determine the relationship between insect abundance and hydropower operations along the river and its tributaries. As demonstrated by the study authors, the scope of the citizen science data set far exceeded what professional scientists could have collected on their own.

Cliffhangers Collect Hard-to-Get Information

Man with helmet hangs from ropes off a rocky cliff — Image credit: NPS / Emily Hassell

Rock climbers and canyoneers, represented by groups such as Climbers for Bat Conservation and American Climber Science Program, are actively involved in citizen science. Zion National Park is working in partnership with local climbers to locate and document bat roost sites to monitor bats for White-Nose Syndrome, a deadly disease.

Climbers can look for raptors and submit their observations to an online database.

The climbing community in Boulder, Colorado, partners with Rocky Mountain National Park to monitor active raptor nests. Many sites are closed to climbing during nesting season. But when sites are open, climbers can look for raptors and submit their observations to an online database. Pinnacles National Park has a similar partnership to help protect threatened raptors and their nests.

Counting Roadkill to Help Animals Survive

A woman stands smiling next to her red bike. She is wearing a red helmet and backpack. She is on an old logging road surrounded by green grass and foliage. — Image credit: NPS / Sarah King

Citizen science volunteers can conduct scientific roadkill surveys by car or bicycle, but this work involves special safety considerations due to the hazards of stopping along busy roads. In Glacier National Park, local volunteers identified species and crossing locations along Highway 2 that were helpful in planning and designing wildlife crossings.

Participants can see who among their peers have made the most observations or found the most animal species.

The National Park Service has a service-wide iNaturalist project for animal mortality that has recorded tens of thousands of observations so far. Participants can see who among their peers have made the most observations or found the most animal species. There’s also a list of the most observed species and an interactive map of observations. Citizen scientists helped Saguaro National Park estimate the number of animals killed on park roads each year. The park is using the information to better determine where and how to protect wildlife.

“Superheroes” and Neighbors Increase Project Scope and Depth

Two women and a man examine a cottonwood tree — Citizen scientists with the USA National Phenology Network examine a cottonwood tree on Mt. Lemmon near Tucson, Arizona.
Image credit: NPN / Brian Powell

National parks have superhero volunteers. They’re local residents (often retired) who are committed to a park and its projects long term. Keith Boden, a volunteer trail runner in Santa Monica Mountains National Recreation Area, single-handedly kept a wildfire monitoring study going for several years. Saguaro volunteers Chuck Perger and Mike Chehoski have collected hydrology data in the park for nearly 20 years.

Because they study shifts in seasonal timing, projects incorporating phenology may work best with longer-term volunteers who can become experts. Erin Posthumus is an outreach coordinator and U.S. Fish and Wildlife Service liaison with the National Phenology Network. She found that a framework of people making observations together with a more experienced person to help them through the process and follow up works best.

In a study of elk migration in Wyoming, neighbors helped park biologists confirm major wildlife corridors.

An incredibly successful example of this is at Great Smoky Mountains National Park, where a team of well-organized volunteers documents the timing of tree leaves, flowers, fruit, and fall colors weekly during the growing season. Scientists have used citizen science data from this and other national parks to examine the timing of leaf out and other life-cycle stages associated with changes in the earth’s environment.

As neighbors collecting data outside protected area boundaries, citizen scientists can sometimes broaden the scope of scientific studies. In a study of elk migration in the National Elk Refuge in Wyoming, neighbors helped park biologists confirm major wildlife corridors and add finer-scale details to migration maps.

Online Volunteers Chronicle the Present and Preserve the Past

A person studies a beetle using a computer — Image credit: NPS

Zooniverse is a platform that enables volunteers to help with data analysis from the comfort of their own computers. The platform is free for scientists to set up and easy for volunteers to use. This is good news for parks with projects where citizen scientists can work remotely. One common project of this type asks volunteers to identify species from wildlife camera photos using photo guides. Santa Monica Mountains National Recreation Area is a partner in the Wildlife of Los Angeles Zooniverse project. Volunteers take an online tutorial to learn how to identify species in the photos, then set to work.

At Homestead National Historical Park, citizen scientists transcribe original documents from Black homesteaders in the 1870s–1930s into digital formats.

In the Black Homesteading Project at Homestead National Historical Park, citizen scientists also work online. They transcribe original historical documents from Black homesteaders in the 1870s–1930s into digital formats so they can be shared with scholars and the public.

A man in a red shirt and cap holds a stick up against a tall saguaro cactus — A citizen scientist measuring a saguaro cactus.
Image credit: NPS

A Winning Formula

Rick Bonney is Senior Extension Associate Emeritus at the Cornell Lab of Ornithology in Ithaca, New York. He emphasizes that effective citizen science starts with the same principles as any other way of conducting science:

Recognizing the broad context and need for a research study or program
Establishing clear and specific goals
Creating sound study designs that pay attention to methods, logistics, and safety

The Organic Act of 1916 explicitly states that park resources should be protected for future generations to enjoy. In order to do that, parks need good scientific data and plenty of it. For this, long-term studies are just as important as research that addresses immediate, park-specific concerns. All parks have long- and short-term scientific goals. Many, if not most, seek to measure long-term ecological changes resulting from climate change. Some want to know how many visitors are trampling a sensitive meadow, or how wildlife is responding to management actions. These are just a couple of examples from a vast and exciting arena of possibility.

It’s important to create projects that participants find rewarding and to collect information that’s actually used.

The universe of citizen science is huge and growing. But to effectively take advantage of this trend, it’s important to create projects that participants find rewarding and to collect information that’s actually used. Successful citizen science programs first develop a project with the above-mentioned principles in mind before they enlist volunteers to do the work in the field. Sometimes opportunities present themselves unexpectedly and with short notice, and the desire to collect data can be strong. But without a clear process and purpose this can lead to disappointment and disillusion.

The best citizen science programs respect their volunteers’ time. Volunteers appreciate being thoughtfully directed to undertake tasks they have the skills and time for. They also enjoy feedback and rewards for the work they’ve done. Sofia Corely with the Schoodic Institute at Acadia National Park emphasized that people are most motivated if they feel like they contribute to science and the park or forest they love. “Actual science is really important,” she said. “People want to know where their data are going and how it is being used.” From such humble beginnings come major breakthroughs.

Man in NPS uniform standing next to saguaro cactus — Image credit: NPS

About the author
_{Don Swann is a biologist with Saguaro National Park.}

The Devoted People behind Big Data in National Parks

Citizen science volunteers collect massive amounts of crucial scientific information. They gather it from sources as varied as oceans, mountainsides, and historic archives. Smart new tools are making their contributions even more powerful.