SciStarter’s Top 5 Citizen Science Projects of 2021

More than 120,000 people of all ages made more than 2.6 million contributions from all over the globe to citizen science projects through SciStarter in 2021!

You can join them in providing this invaluable data to scientists, researchers and conservationists by playing games, taking surveys, analyzing data and reporting observations. Here are the top 5 citizen science projects that received the most data contributions from our users in 2021. Try them out for yourself!

Happy 2022,
The SciStarter Team

Image credit: Stall Catchers

This game-playing app is speeding up Alzheimer’s research.

Scientists at Cornell University have discovered links between stalls — clogged blood vessels in the brain — and Alzheimer’s disease. By reducing the number of stalls, the lab was able to restore memory and reduce other cognitive symptoms in mice.

Help scientists recognize and report stalls by watching videos from the brains of mice and scoring blood vessels as “flowing” or “stalled.”

Location: Online

Get Started!

Image credit: CoCoRaHS

Use low-cost measurement tools to report on the weather in your area. Simply monitor precipitation and utilize CoCoRaHS’s interactive website to provide data for natural resource, education and research applications.

Location: North America

Get Started!

Image credit: iNaturalist

Have you ever been on a walk and wanted more information on an interesting flower? Wonder no more with the iNaturalist app.

Snap photos of trees, flora, fauna, insects and animals to learn more about your observations. Better yet, every observation contributes to biodiversity science, from the rarest butterfly to the most common backyard weed. Scientists gather data about the natural world from your images — all you have to do is observe!

Location: Global

Get Started!

Image credit: Andreas Berlin/Unsplash

Attention, cool cats and kittens! Researchers need your help tracking wildcats and their prey in Costa Rica’s Osa Peninsula. Thousands of “wildlife selfies” are taken by motion-sensor cameras and scientists need your help identifying the animals in these images. Join now to help conservation science and increase knowledge of wildlife species.

Location: Global

Get Started!

Image credit: Alexia Ellesse/Unsplash

Virtually travel to Lewa Wildlife Conservancy in Kenya and aid conservation research.

Camera traps monitor this 93,000-acre conservancy and scientists need your help identifying areas that have high wildlife traffic. Report what you see in the photos to help identify high-traffic areas and to monitor which species are using these conservation corridors. Keep your eyes out for a wide variety of wildlife, including endangered species like Kenya’s black and white rhino and the Grevy’s zebra.

Location: Global

Get Started!

Events and Opportunities

Professional Development for Libraries, Part Two: A Deeper Dive into Citizen Science Kits

January 26, 2022

In the second part of our library series, we’ll dig in to the nitty gritty of citizen science kits. RSVP for the free webinar on how to take your community science engagement to the next level!

Make your library a community hub for citizen science!


Professional Development for Libraries, Part Three: Planning for Citizen Science Month

February 10, 2022

RSVP for a free webinar to explore how libraries can prepare for this year’s Citizen Science Month!

Learn more!

New On The Blogs:

The Top 21 Citizen Science Projects of 2021 via the SciStarter Blog

Citizen Science Project Leaders: Here’s How and Why To Become a SciStarter Affiliate via the SciStarter Blog

Four People, Four Different Paths Into Citizen Science via the SciStarter Blog

Keep Exploring

Discover more citizen science on the SciStarter calendar. Did you know your SciStarter dashboard helps you track your contributions to projects? Complete your profile to access free tools. Want even more citizen science? Check out SciStarter’s Project Finder! With citizen science projects spanning every field of research, task and age group, there’s something for everyone!

Categories: Uncategorized

About the Author

SciStarter Team

SciStarter Team

SciStarter connects you to thousands of searchable citizen science projects in need of your help. Use the Project Finder ( to find a project to match your location, interests, and age level. Your free SciStarter account will help you earn credit for participating in projects across apps and websites (use the advanced search option at to find Affiliate projects eligible for credit in your dashboard). Together, we can move the world forward!