The following piece was written by OAS Communications Coordinator Ryan Bower for the Snapshot Wisconsin newsletter. To subscribe to the newsletter, visit this link.

Since Snapshot reached 50 million photos, the Snapshot team felt it was a good time to address one of the most asked questions about photos: what happens to photos once they are uploaded by volunteers? At first, the process seems complicated, but member of the Snapshot team, Jamie Bugel, is here to walk us through the process, one step at a time.

Bugel is a Natural Resources Educator and Research Technician at the DNR, but she works on the volunteer side of Snapshot. Bugel said, “I mainly help volunteers troubleshoot issues with their equipment or with their interactions with the MySnapshot interface. I am one of the people who answer the Snapshot phone, and I help update the user interface by testing functionality. There is also lots of data management coordination on the volunteer side of the program that I help with.”

Bugel listed off a few of the more common questions she and the rest of the Snapshot team get asked, including who reviews photos after the initial classification, what happens to the photos that camera hosts can’t identify and how do mistakes get rectified. “We get asked those [questions] on a weekly to daily basis,” said Bugel.

It Starts With a Three-Month Check and an Upload

Every three months, trail camera hosts are supposed to swap out the SD card and batteries in their trail camera. At the same time, volunteers fill out a camera check sheet, including what time of day they checked the camera, how many photos were on the SD card and if there was any equipment damage.

“You should wait at least three months to check their camera, because you won’t disturb the wildlife by checking more often. We want to view the wildlife with as minimal human interference as possible,” said Bugel. “At the same time, volunteers should check [their camera] at least every three months, because batteries don’t last much longer than three months. Checking this often is important to avoid missing photos.”

After the volunteer does their three-month check, they bring their camera’s SD card back to their home and enter the information on their camera check sheet into their MySnapshot account and upload their photos.

Bugel said it can take anywhere from 4 to 48 hours for the photos to appear in the volunteer’s MySnapshot account. Fortunately, the server will send an email when the photos are ready, so volunteers don’t have to keep checking. Volunteers can start classifying their photos after receiving the email.

Initial Classification By Camera Hosts

The first round of classification is done by the trail camera hosts. The returned photos will sit in the Review Photos section of their MySnapshot account while the host classifies the photos as Human, Blank or Wildlife. The wildlife photos are also further classified by which species are present in the photo, such as beaver, deer or coyote.

This initial classification step is very important for protecting the privacy of our camera hosts, as well as helps on the back end of data processing. Over 90% of all photos are classified at this step by the camera hosts. When they are done classifying photos, they click “review complete,” and the set of photos is sent to the Snapshot team for the second round of classification.

Staff Review

The second round of classification is the staff review. Members of the Snapshot team review sets of photos to verify that all human or blank photos have been properly flagged. “For example, a deer photo may include a deer stand in the background. That type of photo will not go to Zooniverse because there is a human object in the photo,” said Bugel. Fortunately, nearly all human photos are taken during the initial camera setup or while swapping batteries and SD card, so they are usually clumped and easy to spot.

The second reason that staff review photos after the initial classification is for quality assurance. Since some animal species are tricky to correctly classify, someone from the Snapshot team reviews sets to verify that the photos were tagged with the correct species. This quality assurance step helps rectify mistakes. “Sometimes there are photos classified as blank or a fawn that are actually of an adult deer,” said Bugel. “We want to catch that mistake before it goes into our final database.”

In cases where the set of photos wasn’t classified by the camera host, the team will also perform the initial classification to remove human and blank photos. The Snapshot team wants to make sure any photos that reveal the volunteer’s identity or the location of the camera are removed before those photos continue down the pipeline.

Branching Paths

At this point in the process, photos branch off and go to different locations, depending on what classification they have. Blank (43%) and human (2%) photos are removed from the pipeline at this point. Meanwhile, the wildlife photos (20%) move on to either Zooniverse for consensus classification or move directly to the final dataset. The remaining photos don’t fall into one of our categories, such as the unclassified photos still awaiting initial review.

Photos of difficult-to-classify species, such as wolves and coyotes, are sent to Zooniverse for consensus classification. Bugel explained, “The photos [of challenging species] will always go to Zooniverse, even after volunteer classification and staff member verification, because we’ve learned we need more eyes on those to get the most accurate classification possible,” another layer of quality assurance.

Alternatively, photos with easy-to-classify species, such as deer or squirrel, go directly to the final dataset. Bugel said, “If a photo is classified as a deer or fawn, we trust that the volunteer correctly identified the species.” These photos do not go to Zooniverse.

Zooniverse

Photos of difficult-to-classify species or unclassified photos move on to Zooniverse, the crowdsourcing platform, for consensus classification. “Wolf and coyote photos, for example, always go to Zooniverse, because it is so hard to tell the difference, especially in blurry or nighttime photos,” said Bugel.

The Snapshot team has run accuracy analyses for most Wisconsin species to determine which species’ photos need consensus classification. All photos of species with low accuracies go to Zooniverse.

On Zooniverse, volunteers from around the globe classify the wildlife in these photos until a consensus is reached, a process called consensus classification. Individual photos may be classified by up to eleven different volunteers before it is retired, but it could be as few as five if a uniform consensus is reached early. “It all depends on how quickly people agree,” said Bugel.

Team members upload photos to Zooniverse in sets of ten to twenty thousand, and each set is called a season. Bugel explained, “Once all of the photos in that season are retired, we take a few days break to download all of the classifications and add them to our final dataset. Then, a Snapshot team member uploads another set of photos to Zooniverse.” Each set takes roughly two to four weeks to get fully classified on Zooniverse.

To date, over 10,400 people have registered to classify photos on Zooniverse, and around 10% of the total photos have been classified by these volunteers on Zooniverse.

Expert Review

It is also possible for no consensus to be reached, even after eleven classifications. This means that no species received five or more votes out of the eleven possible classifications. These photos are set aside for later expert review.

Expert review was recently implemented by the Snapshot team and is the last step before difficult photos go into the final dataset. The team has to make sure all photos have a concrete classification before they can go into the final dataset, yet some photos never reached a consensus. Team members review these photos again, while looking at the records of how each photo was classified during initial review and on Zooniverse. While there will always be photos that are unidentifiable, expert review by staff helps ensure that every photo is as classified as possible, even the hard ones.

The Final Dataset and Informing Wildlife Management

Our final dataset is the last stop for all photos. This dataset is used by DNR staff to inform wildlife management decisions around the state.

Bugel said, “The biggest management decision support that Snapshot provides right now is fawn-to-doe ratios. Jen [Stenglein] uses Snapshot photo data, along with data from other initiatives, to calculate a ratio of fawns to does each year and that ratio feeds into the deer population model for the state.”

Snapshot has also spotted rare species too, such as a marten in Vilas county and a whooping crane in Jackson county. Snapshot cameras even caught sight of a cougar in Waupaca county, one of only a handful of confirmed sightings in the state.

The final dataset feeds into other Snapshot Wisconsin products, including the Data Dashboard, and helps inform management decisions for certain species like elk. Now that the final dataset has reached a sufficient size, the Snapshot team is expanding its impact by feeding into other decision-making processes at the DNR and developing new products. 

The Snapshot team hopes that this explanation helps clarify some of the questions our volunteers have about what happens to their photos. We know the process can seem complicated at first, and the Snapshot team is happy to answer additional questions about the process. Reach out to them through their email or give them a call at +1 (608) 572 6103.