Global Community Science

Published April 6, 2023

From April 28–May 1, the City Nature Challenge (CNC) returns to invite residents of more than 400 cities to discover wildlife on their blocks and in their backyards.

What began as a friendly competition between Los Angeles and San Francisco has blossomed into a worldwide week-long hunt for wild critters, plants, fungi, and everyone’s favorite–slime molds–to be photographed and uploaded to the crowd-sourced science platform iNaturalist. More than pretty pictures, these observations are making an impact in conservation and research happening around the world–and at institutions like the Natural History Museum. 

In 2022, more than 67,000 people made 1,694,877 observations worldwide, representing more than 50,000 species, including 2,244 rare and endangered species. Each year brings more cities and more participants to the CNC, which means we’ll likely see even more observations in 2023. From May 2–7, researchers identify these observations as close to the species level as they can get from the images, but what happens then? That’s when the real science gets going. 

“The City Nature Challenge is an opportunity for all Los Angeles County residents to slow down, put on their nature eyes, and notice just how many wild plants, animals, fungi, and slime molds can be found in their own neighborhoods--all while engaging in friendly competition with cities around the world and helping researchers answer important questions about biodiversity in urban areas.”
Amy Jaecker-Jones,  Community Science Program Manager 

Every photo submitted has the potential to impact research and conservation policies. All those observations combined create datasets that would be completely unavailable to researchers like the curators working at NHM, and those new datasets are opening doors to new research. 

 BAILA (Biodiversity Analysis in Los Angeles) publication and report
This collaborative effort between NHM and The Nature Conservancy used 59,842 iNaturalist observations from more than 10,000 iNaturalist users, including many observations generated during the City Nature Challenge. When published in 2019, the BAILA project was the largest research dataset to use iNaturalist observation.
iNaturalist photo 258886309 by ant, like the bug

Much like museum specimens, each crowd-sourced observation is a record of an organism at a specific time and place, and the more records you have, the more you can say and study about those organisms and the environment they live in–whether it’s the bottom of the ocean or just around the block. 

Here are some of the ways NHM’s scientists are using all that precious data to protect our planet and how your observations can help their research. Some of the curators in NHM’s Urban Nature Research Center (UNRC) have shared some of the research that’s already been made possible by these kinds of observations, along with some avenues for future research and what they’re looking for right now.

NHM’s Curator of Herpetology and Director of the UNRC Dr. Greg Pauly has been making great use of crowd-sourced observations in his Reptiles and Amphibians of Southern California (RASCals) community science project to better understand native and non-native reptiles and amphibians across the region.

Community science observations have been crucial to identifying non-native species. Non-natives are any species brought into the region directly or indirectly through human activity and now living outside their natural distribution. Invasive species cause harm to the environment, the economy, or even human health. Finding non-native species quickly is the best way to prevent them from becoming invasive in the first place, what conservation biologists call “early detection-rapid response”.

Non-native species frequently turn up in residential or commercial areas first–exactly the places where professional biologists are unlikely to survey, making it hard for them to discover non-native species. Community scientists who live and work in these areas open a window into places that biologists like Pauly might not have access to or would be unlikely to go to search for a non-native species. The observations they’ve shared have revealed species like green anoles native to the Southern U.S. and African five-lined skinks among many others showing up here in Southern California. 

In the case of the African five-lined skink, Pauly and the original observer met with local community members for guidance and prevented the African five-lined skink from establishing itself in L.A. ecosystems. They were able to successfully eradicate the non-native species–a rare achievement outside of island ecosystems where the ocean acts as a barrier. This work demonstrated that iNaturalist can be especially useful for quickly detecting non-native species, representing a possible model for future efforts. 

Community scientist Patrick Gavit photographed and posted an image of an unusual-looking lizard on iNaturalist, which Pauly identified as the African five-lined skink (pictured above). The pair co-authored a paper about this population documenting the first time this species had become established in California and only the second time this species had become established in the U.S.
iNaturalist photo 174750264 by Светлана Царахова

A lot of local wildlife is literally in Angelenos’ backyards, but those backyards are also private property. To conserve that wildlife, biologists like Pauly need to understand how urbanization is impacting local species like SoCal’s widespread–but secretive–alligator lizards. 

A southern alligator lizard (Elgaria multicarinata)
iNaturalist photo 203096379 by  Chris DeGroof, used with permission

CNC observations helped Pauly and his coauthors discover the human-caused threats facing these elusive lizards. Photos revealed they were more likely to have popped their tails off–a defense meant to distract predators, likely house cats–but were less likely to suffer from parasites like ticks–ironically, likely due to urban pets being treated for the parasites. Residents’ observations helped scientists understand how species are making it in the suburbs and the cities–and what we can do to help them thrive. 

Right now, Pauly is looking for photos and videos of alligator lizards mating, one of the behaviors that biologists like him might never encounter on their own (Pauly still hasn’t seen it happen with his own eyes), but are able to study thanks to the many watchful eyes of community scientists whose observations have produced probably the largest dataset ever of mating behavior in a lizard or snake.

Two males biting the head and neck region of a female Southern Alligator Lizard observed in the Baldwin Hills neighborhood of Los Angeles.

Observations of alligator lizard mating help researchers understand how weather–and the increasingly erratic weather we’re experiencing due to climate change–might impact when these lizards breed. “These observations demonstrate that crowd-sourced photographs and data collection can revolutionize the field of animal behavior,” says Pauly. Almost every year, participants in the CNC upload new observations of this rarely observed behavior. 

Every observation of alligator lizards mating is important.”
Dr. Greg Pauly 

NHM’s Associate Curator & Twila Bratcher Chair in Malacology (and Associate Director of the UNRC) Dr. Jann Vendetti has found iNaturalist observations–and the observers behind the photos–invaluable resources for her studies on the land snails and slugs sliming up L.A.

Photos from the seasonal community science SnailBlitz project and the ongoing SLIME project (Snails and slugs Living In Metropolitan Environments, obviously) have contributed to papers identifying introduced species of snails and slugs. 

Identifying these introduced species early–especially being able to identify where they might be parking their shells through location data in iNaturalist–can help protect the natural habitat and native species of Southern California by making it easier for policymakers to take protective measures around a crop or imported good that might be threatened by or carrying potentially invasive slugs or snails. 

Just as important, identifying where endangered and threatened native species are hanging on can help add much-needed support to conservation efforts, like in the case of the San Gabriel chestnut snail (Glyptostoma gabrielense) and the California shoulderband snails (Helminthoglypta sp.). These native SoCal snails are generally understudied, and every new observation helps researchers like Vendetti understand their ranges and further bolster calls to protect habitats. 

iNaturalist observations were used in the petition to have the San Gabriel chestnut snail (pictured above) listed as an endangered species. 
iNaturalist photo 263357982 by Susan Hopkins

For what I'm working on now, any good, close-up, and focused images that include the shell and body would be best. Usually, a focused image of the whole body of a snail or slug is enough to get a good ID. For Helminthoglypta snails, it is especially important to get a good image of the sculpture of the shell. Subtle differences in shell sculpture are sometimes enough to identify species that otherwise look almost the same.”
Dr. Jann Vendetti

 

The fox squirrel is the second most commonly-observed animal in L.A. County on iNaturalist (right behind the western fence lizard), and NHM’s Assistant Curator of Mammalogy Dr. Kayce Bell would like to change that by getting more of the other species of squirrel and chipmunk (the family of small rodents known as Sciuridae) native to the County better represented on the platform. 

She is now helping to manage the Southern California Squirrel Survey, an NHM community science project tracking all those bushy-tailed beasts and their less well-endowed cousins (chipmunks) scurrying up the trees and fences in your neighborhood. Her recent poster, coauthored with other NHM colleagues, outlines where squirrels and chipmunks have been found across the region, but she’s looking to build out the Survey with more observations and hoping to identify where these different squirrels and chipmunks have taken up residence–in urban backyards and further afield. 

Using Museum specimens and iNaturalist observations, Dr. Kayce Bell and other NHM researchers put together a map of where different species of squirrels and chipmunks are living and how that's changed over time. Find out which squirrels are in your neck of the woods by checking out the whole map here!

Using data from iNaturalist, Bell and other NHM researchers were able to map out where all those nutty little mammals are living, and getting more observations of squirrels and chipmunks beyond the fox squirrel will go a long way to figuring out where Southern California squirrels are thriving and where they are not.  

What do you want to see? “More squirrels! It would be great to get observations of more squirrels that aren't fox squirrels, especially in areas that are on the edge or adjacent to urbanized/developed areas.”
Dr. Kayce Bell. 

While museum specimens like NHM’s are the gold standard for keeping track of species across time and geography– community scientists’ observations for projects like the CNC can beef up numbers and fuel conservation strategy. Just like researchers a hundred years ago could not know how modern scientists are using advanced tools like scanning electron microscopes and DNA analysis to get new information out of century-old museum collections, exactly how future researchers might use crowd-sourced observations is impossible to say, but iNaturalist observations are already playing a crucial role in the research of many NHM scientists.   

As Assistant Curator of Ornithology at NHM, one of the many things Dr. Allison Shultz studies is the finer points of feathers.

Using powerful microscopes and other analytical tools, Shultz uncovers the mysteries of how birds achieve their incredible colors among other feathery feats. For Shultz, crowd-sourcing images offers the chance to analyze truly impressive displays of atypical plumage–things like leucistic (albino) birds for example. 

I’m looking for observations of birds with atypical feathers. So keep a look out for oddly colored feathers, but remember that every observation can be valuable for research.”
​​​​​Dr. Allison Shultz

A single researcher hardly ever encounters such atypical feathers on their own, but the 1.6 million observers contributing to iNaturalist mean there are more chances to find rare plumage than ever before, even if any individual user isn’t looking for it. iNaturalist observations create sample sizes large enough for scientists like Shultz to study bird biology in new ways, and those avenues of discovery are just ramping up.

An extreme example of a leucistic bird, this American crow (Corvus brachyrhynchos) has completely white plumage. Any noticeable variation in feather pigmentation is especially rare.
 iNaturalist photo 228079502 by user Justin (CC BY-NC)

“For example, birds lacking melanin might uncover pigments and patterns that are otherwise hidden,” says Shultz. “Or, you can look at what happens to feathers over time when they are missing important components of their pigments/structure. Or, seeing how living in less than pristine environments might actually cause birds to have more mutations (e.g., DNA damage), resulting in feathers losing color. There are so many possibilities!”

This melanistic Cooper's hawk (Accipiter cooperii) is another incredibly rare find, identified only a handful of times in the literature. Its feathers are much darker than a typical Cooper's hawk. iNaturalist helps increase the number of observations of rare animals like this. iNaturalist photo 5566681 by John Karges (CC BY-NC)

iNaturalist launched in 2008 as part of a UC Berkley Master’s project, and the City Nature Challenge was only founded in 2016. iNaturalist users and observations continue to grow exponentially, just as the CNC adds new cities and participants every year. It’s a virtuous cycle of growth. CNC helps create new community scientists while adding more observations from more parts of the world, and all those accumulated observations will continue to become even more useful over time, making new research possible and expanding our understanding of biodiversity in our cities and on our planet. 

Researchers estimate that there are 8.7 million species on Earth and around 86 percent are still waiting to be fully described.

That means there are more than 7 million species unknown to science. Some of those unknown species are probably waiting in museum collections like NHM’s for the careful eye of expert taxonomists, but others are flying, crawling, creeping, slithering (you get the idea), in the wild and not-so-wild places all around us. 

In 2021, two high school students were scouring iNaturalist and found a Southern California scorpion observation that had gone unidentified for six years.

Through carefully studying and comparing anatomical features to known scorpions, the pair eventually realized that these were each new to science. The species they named Paruroctonus soda (after Soda Lake, not any beverage) and Paruroctonus conclusus (another iNaturalist observation that went unidentified for around a year) could have remained some of the 7 million or so unidentified organisms–their ranges are limited to the salty, dried lake beds found in the desert called playas. Paruroctonus soda’s range is entirely within the Carrizo Plain National Monument, but P. conclusus’s territory is unprotected. A construction project could wipe out the entire species, and we might be none the wiser. Crowd-sourced science observations made their discovery possible along with any attempts to conserve and study them. 

An image from the paper describing the two new scorpion species depicting an addult female Paruroctonus soda with 51 newly born juveniles
(CC BY 4.0)

These are just a tiny fraction of the research and discoveries made possible by projects like the City Nature Challenge and platforms like iNaturalist. The impressive list of publications and discoveries in community science projects like the CNC will only grow over time. So from April 28–May 1, be sure to slow down, put on your nature eyes, and take some pictures of what you see out there. Your photo makes a difference.