A National Collaboration Releases Their First Publication

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

For the last three years, Snapshot Wisconsin has been contributing to a similar citizen science program called Snapshot USA, and Snapshot USA recently reached an important milestone worth celebrating. They released their first publication! Congratulations, Snapshot USA!

In honor of Snapshot USA reaching this milestone, the Snapshot Wisconsin team wanted to highlight this fellow citizen science project and share with our volunteers a lesser-known way that Snapshot Wisconsin data is being used.

What is Snapshot USA?

Snapshot USA is a national effort to bring together trail camera data from across the country and learn about what drives the distribution of mammal species within the United States. Snapshot USA takes a similar approach to Snapshot Wisconsin, having people classify trail camera photos to generate usable data for science. The main differences are that Snapshot USA is a nationwide effort and is focused entirely on mammals.

Snapshot USA was organized in 2019 by scientists from the North Carolina Museum of Natural Sciences and the Smithsonian Conservation Biology Institute. They asked fellow researchers, citizen science programs (including Snapshot Wisconsin) and private citizens to upload and classify their trail camera photos. Much to everyone’s excitement, over 150 people and programs participated in the effort.

Better yet, people contributed photos from 110 locations across all 50 states, proving that there are people all over this country who value efforts like Snapshot USA and Snapshot Wisconsin.

Snapshot Wisconsin’s Contributions

For our part, the Snapshot Wisconsin program was thrilled to support a fellow citizen science project. We submitted data from 2019 and 2020, and we are working on submitting data from this last year as well. It is important to us to support other programs like Snapshot USA and build up science together.

Every year, Snapshot Wisconsin has contributed data from around 10 of our trail cameras in the Clam Lake elk camera grid. Snapshot USA required at least ten cameras clustered within a 5km area, so only a few areas of our camera grid like the elk camera grids met the requirement.

Despite limitations in which cameras we could include, the Snapshot Wisconsin team is glad that we were able to contribute to this effort at all. Jennifer Stenglein, one of Snapshot Wisconsin’s lead scientists, said, “Snapshot Wisconsin is not set up to have areas with clustered cameras. We made a special exception for the elk grid because the data are used to monitor the growing elk herds across the state. Fortunately, the elk grid matched the minimum requirements to participate.”

Stenglein also mentioned how important it was to her personally that Snapshot Wisconsin contributed to this nationwide effort. “As a scientist, having open data is huge. There is so much trail camera data out there, but it’s [isolated] to specific programs or people. Snapshot USA created a place for trail camera data to come together and be available. That allows scientists to ask questions we couldn’t before, like how climate change is impacting species at a national level.” Stenglein is excited to see what other researchers do with the compiled data.

A bull elk with antlers

How Snapshot USA Operates

In addition to sampling populations from across a wider scale than Snapshot Wisconsin, Snapshot USA samples from all major habitats and development zones found within the United States. When a new collaborator joins the program, they select the combination of setting (Urban, Suburban, Rural, Wild, Other) and habitat (Forest, Grassland, Desert, Alpine, Beach, Anthropogenic, Other) that matches their camera site.

Our volunteers may notice that some of these site combinations differ from what Snapshot Wisconsin uses. For example, urban deployment does not fit Snapshot Wisconsin’s criteria for setting up a camera. Stenglein thought that the addition of urban areas adds an interesting element to the dataset, but it shows a fundamental difference in what Snapshot Wisconsin and Snapshot USA are trying to capture.

Next, collaborators upload their photos from a specified time window. In 2019, Snapshot USA collected photos from the 14-week period from August to November. Once uploaded, collaborators could start classifying photos, similarly to how our camera hosts do it.

One important difference is that Snapshot USA puts all their photos through a second round of classification – this time by an expert. Expert review happens within Snapshot Wisconsin as well, but only for the species we’ve learned are classified with lower accuracy. Our accuracy analyses have shown that volunteers do a great job of accurately classifying most species, especially the most common species, so Snapshot Wisconsin only expertly classifies the photos of the hard-to-classify species and rare species. Besides, Snapshot Wisconsin would not be able to expertly classify its 60+ million photos. However, this extra step is possible for a program like Snapshot USA.

“Limiting the time window for data collection is really common in trail camera studies,” said Stenglein. “I don’t know if there is any perfect time window for Snapshot USA to choose, since you will always miss something. However, it does make sense for them to select a window of time. It would be too challenging to collect a whole year’s worth of data, let alone have an expert review.”

Once both rounds of classifications are done, the data are assembled into a package and prepped for release in the form of a new publication. This type of publication is called a “data paper” because its main purpose is to release a new dataset for others to work with.

“It’s a cool, new trend in science for data papers to come out,” said Stenglein. “I’ve seen more effort being put towards proper archiving of data. Researchers can use these datasets to test their own hypotheses and come up with new and exciting insights into wildlife distributions in the USA. I think this is where research needs to be, so it’s encouraging to see this trend.”

A wolf in an open marsh

2019 Data Is Released

In April 2021, Snapshot USA officially published their 2019 dataset. The paper was published in the scientific journal Ecology and had around 100 different authors.

In total, the dataset included photos from 1,509 cameras across 110 locations, and all 50 states and the District of Columbia contributed data. The dataset had 166,036 observations (photos) and found 83 unique mammal species. Seventeen bird species were also detected, which impressed Stenglein, but the project wasn’t looking for birds, only mammals.

“All together, that’s an impressive number of species detected,” said Stenglein. “Trail cameras aren’t set up to see all species equally. Birds, for example, often spend most of their time above the line of sight of cameras, so capturing 17 species of birds is pretty cool.”

Snapshot Wisconsin’s contributions included sightings of just over 20 of the 83 mammal species found by Snapshot USA. Given the small area that the photos came from, seeing 20 species is a healthy number. If we were able to use more of the grid, that number would have been much higher.

The paper reported that the three most detected species nationwide were white-tailed deer, squirrels and raccoons, in that order. Snapshot Wisconsin’s own data visualization tool, the Data Dashboard, also shows a similar trend, with white-tailed deer and squirrels being the top two species detected in Wisconsin. Racoons weren’t third, but they are high on the list.

Coyotes were the most widespread species detected across the nation, which surprised some of the Snapshot Wisconsin team. However, Stenglein explained, “It may be because there is only one major species of coyote. Deer and other common animals change species as you go across the country. Mule deer, white-tailed deer and black-tailed deer each have different ranges across the U.S.”

What’s Next?

Stenglein was proud of the Snapshot USA team for pulling this effort together. As one of the main researchers for Snapshot Wisconsin, Stenglein knows how much work it is to collect photos from hundreds of sources and extract usable data from them. Stenglein mentioned that it is great to see another citizen science project release their first publication. “Our Snapshot Wisconsin team only has so much capacity to work on decision-support tools, so it is cool to know that these data will be used in more ways and by more people.”

Stenglein also mentioned that there is a second publication in the works already. This publication will release the 2020 dataset. It’s nice to see such a quick turn around time for the second publication.

“The peer review process can easily take months to years,” explained Stenglein, “so there will always be a lag. However, I expect that this first lag will be the biggest. I’ve already seen process improvements on the data uploading side. They’ve moved to a more efficient process, which really helps.”

Stenglein believes Snapshot USA has expanded its data collection to Europe as well for the 2021 season, which could offer some interesting comparisons for researchers.

Stenglein’s final thoughts for the Snapshot USA program were:

“I’m so impressed that they pulled this off. We know from Snapshot Wisconsin how difficult it can be to keep things running smoothly, especially when it comes to IT infrastructure and solutions. I wish Snapshot USA all the luck as they continue to expand their program, and I look forward to working with them each year. What you’ve accomplished is impressive. Remember that.”

February #SuperSnap

We have chosen a striped skunk for this month’s #SuperSnap from Douglas County. Did you know that striped skunk is one of the species of interest found on the Snapshot Wisconsin Data Dashboard? Visit the dashboard to see Snapshot Wisconsin trail camera detections of striped skunk visualized by county as well as time of day and year. Stay posted for 2021 data to be added later this year!A striped skunk walking in an open field

A huge thanks to Zooniverse participant @WINature for the #SuperSnap nomination!

Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.

Submit a Caption for Snapshot Photos!

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

Jessica Knackert, one of the newest Snapshot team members, recently added a new discussion called “Funny Photo Captions” to the Zooniverse Talk Board. This discussion contains funny trail camera photos for volunteers to add their own captions. Take a look as Zooniverse volunteers have already contributed several entertaining captions.

For those who don’t know, Zooniverse is a platform that is used by citizen science projects to expand their reach to a wider community of volunteers. Snapshot Wisconsin uses Zooniverse to draw a consensus classification about trail camera photos, while also involving people from all over the world.

Zooniverse’s Talk Board feature allows volunteers to share photos, get second opinions and meet fellow volunteers. The talk board is also one of the easiest ways for volunteers to connect with the larger volunteer community.

Within the new talk board, volunteers can add photos to four categories that the Snapshot program frequently sees: Animal Selfies, Comical Situations, Interactions and Animal Yoga.

Knackert is excited to provide another space for volunteers to connect.

“Our volunteers were already captioning photos themselves, but they didn’t have a central place for it. I think this board is a great place for volunteers to come and enjoy the humor of their fellow volunteers,” said Knackert.

Volunteers were eager to use this new talk board adding captions to photos within its first day of being live.

To keep the fun going, Knackert has added a new batch of photos for people to caption. Plus, volunteers can make their own posts on the talk board with photos they find. There is plenty of fun to be had.

Captions can be funny, silly or clever. However, the team asks that all photos adhere to community standards. Moderators and staff will remove posts that contain spam or language that violates these standards. To meet standards, all posts must be appropriate for all ages and be respectful of the other volunteers who use the talk board. Also, please do not expose personal information of other users, including names or addresses, without their permission.

Now, let’s get to the fun part – seeing some of the captions that volunteers have already posted. Please note that we couldn’t include captions in their entirety here; visit the talk board to read the full caption. The team appreciates submitted captions and the smiles they brought.

A bluebird flying by the camera and looking straight at it

Animal Selfies

The team knew they wanted to include Animal Selfies as one of the categories of funny photos. Snapshot trail cameras are designed to be as quiet and inconspicuous as possible, but animals inevitably get curious. That curiosity leads them to approach the camera and accidentally take a selfie. The team has used several of these selfies in the program newsletter over the years, but new ones come in regularly.

The photo above was posted in the Animal Selfies sub-thread on Zooniverse, and the team chose three captions that made them laugh. We hope you enjoy these volunteer-made captions and feel inspired to add your own to the Animal Selfie post on the talk board.

Caption from Goldfinch33:
“So…you’ve seen this property, we’ve flown around it, you’re happy with the tree heights…can we close this deal?
~said The Bluebird of Avian Real Estate

Caption from bzeise:
I’m blue, da ba dee da ba di WHOAH! What was that?

Caption from sbreich:
Are you looking at me? ARE YOU LOOKING AT ME??

A racoon climbing up a tree

Comical Situations

The second category within the funny photos talk board covers the silly activities we see animals doing in photos. Whether it is slipping on ice or hanging upside down from a branch, these photos capture some entertaining moments that make us laugh. The “levitating” animal photos from the previous article also belong in this category.

The photo of a raccoon barely clinging to a tree (above) was added to the Comical Situations sub-thread and generated some entertaining captions. Here are a few captions submitted by volunteers. If you can think of more captions, don’t forget to add them!

Caption from momsabina:
But he double-dared me….

Caption from charleysangel:
Help! Now what?

Caption from AndyC3339:
Alex Honnold, [a famous rock climber,] made it look so easy!

A mother bear and cub rolling in the grass


If you look at which photos are shared the most on Zooniverse’s Talk Board, fun interactions are always high on the list. Interactions can be between two members of the same species, or they can be interactions between different species. In fact, these photos are so commonly shared that there is a searchable tag (multi_species) that volunteers can use to see photos of multi-species interactions.

The photo of a mother black bear and her cub, playing in the grass was added to the Interactions sub-threaad. Of the three captions, which one is your favorite?

Caption from Megeth:
When I say “roll over” you need to roll. Ready? Roll!

Caption from Swamp-eye:
Mama down, Papa help me up

Caption from charleysangel:
How many paws am I holding up? Wrong

A coyote stretching out its back legs

Yoga Poses

The last category of funny Snapshot photos is Yoga Poses. Cat Pose, Downward Dog Pose, Crow Pose, Cobra Pose and Camel Pose are all named after animals, so it shouldn’t be surprising that we captured some animals stretching in yoga poses.

This type of photo was already covered a year and a half ago on Zooniverse, but there wasn’t an opportunity to caption these photos. The team wanted to bring these photos back for captioning fun. Don’t forget to add your own captions to the Yoga Pose post on the Zooniverse Talk Board.

Caption from Megeth:
“You put your right leg out and you shake it all about”

Caption from bzeise:
Am I doing this planking thing right?

Caption from Goldfinch33:
What?! I do this every morning when I wake up. My mentor told me “stretching exercises every morning without fail keeps joints supple.” Do I move like I’m 9?

Knackert’s Hope For The Talk Board

Knackert thanks everyone who added a caption already and encourages all Snapshot volunteers to join in the fun.

“My hope for this caption board is that it draws in a part of our volunteer community that has never checked out or even knows about Zooniverse. A lot of our volunteers host cameras and only ever classify their own photos. They only get to see the cool photos that they find. I’d love to see those existing volunteers head over to Zooniverse and join in on the conversations happening there.”

If you want to add captions to any of the photos, head over to the Zooniverse Talk Boards and check them out here.

A Thank-you and Farewell from Team Member Michael Kamp

Most of the writing about Snapshot Wisconsin focuses on what the project does for the Wisconsin DNR and the wildlife of Wisconsin or the incredible work of the project’s dedicated volunteers. This makes sense as all are very important aspects of Snapshot Wisconsin. However, for this blog post, I’m going to write about what Snapshot gave to me as a team member and the experience of working for the Snapshot team.

My name is Michael Kamp, and I’ve been with Snapshot Wisconsin a little over two years. Throughout my time, I’ve worked on many different aspects of the project. I’ve done fieldwork, purchasing, equipment shipping, photo classifications and multiple communication pieces for the project. However, I’ll be leaving my position with Snapshot at the end of January to focus on finishing up grad school at UW-Madison this semester. Then I’ll be heading to Ecuador for the summer to work for the Ceiba Foundation for Tropical Conservation. I want to say thank you to my teammates for making Snapshot a great experience for me.


But first, let’s rewind to the fall of 2019. That September, I returned to my hometown of Madison after a stint working for The Nature Conservancy in Rhode Island. I was applying to new positions in the natural resources and conservation realm. I had never heard of Snapshot Wisconsin but applied for a position with the project. Fortunately, I was given an opportunity to interview and then was offered the position. I immediately accepted the job, which also included some administrative responsibilities for our whole office, the Office of Applied Science (OAS).

Certainly, I was excited for my position with Snapshot and OAS, but I didn’t know what to expect. I didn’t know how lucky I was and how transformative the next couple years would be. I grew a lot professionally and personally over my time with Snapshot Wisconsin.

First off, I joined a fantastic team with Snapshot Wisconsin. Throughout all my working experiences, I’ve been continually reminded of the importance of having a great team. Being part of a strong team, I’m motivated to work for my team members and challenge myself. A truly cohesive team makes the difference between a good and great job in my opinion. The Snapshot team made me feel welcome starting on day one with a welcome meeting, and it only improved from there.

While COVID swept through the world shortly afterwards in March 2020, I already had a solid foundation with my teammates. Having this team was super helpful over the course of the pandemic which as we all know is an ongoing challenge. Even if only on a small square on Zoom, I enjoyed seeing my teammates faces.

So, what are some skills I learned from Snapshot? Well, I can now look at very blurry trail camera images and generally identify the animal captured with confidence. I don’t know how transferable this skill will be to other positions if I don’t work with trail camera photos. Nonetheless, I can chalk this up on my resume as “attention to detail.”

I also gained experience in the behind-the-scenes work needed to make a project like Snapshot successful. Communication and organization are essential when gathering the trail cameras and associated equipment. Sending new volunteers’ equipment and replacing any malfunctioning equipment is a big lift, especially with over 1,700 volunteers. We have to send equipment to all corners of the state.

Furthermore, I learned that trail camera photos are a great way to spark an interest in nature. When people asked what my job was, if possible, I simply showed them trail camera photos. People were amazed at all the wildlife that roam Wisconsin, and Snapshot gave them a perfect viewing window. The 50 Million Photo Celebration is an ideal product to showcase beautiful trail camera photos from bear cubs to displaying turkeys.

Coming into this position with birding experience, I became the default bird guy. If there were any bird identification questions regarding trail camera photos, they came to my desk so to speak. Don’t get me wrong – I was quite happy with the arrangement. I was glad to put my bird expertise to use and share it with my colleagues. Snapshot captures mostly ground dwelling birds, but we captured some great warbler photos and even snapped a yellow-billed cuckoo in flight.

What will I take away from this job? A few things come to mind. Snapshot Wisconsin reinforced the idea that teamwork is essential. Wherever I end up in the future, I want to be part of a great team. I also learned the importance of taking advantage of opportunities in your position. For example, I jumped at every chance to complete fieldwork for Snapshot in the reintroduced elk grids. I gained valuable experience using GPS units and determining suitable spots for trail cameras. Many interesting webinars came into my inbox as well, and I attended when able. I continued learning through my whole tenure with Snapshot Wisconsin.

Another takeaway was the value of setting up trail cameras. After joining the team, I set up a trail camera on my family’s land in Vilas County. What a great decision that was! We have stunning photos of red fox, bobcats, and barred owls to name a few. Trail cameras provide a window into the outdoors that can deepen your connection to the land.

At the end of the day, I simply want to say thank you to all my great coworkers. I’m very grateful that my path wound its way to you all and for the experiences we shared together. Honestly, it’s difficult to leave Snapshot, but the time has come for me to move on. Whenever I think back on Snapshot, it will be with a smile. (Even when thinking of the times I had to prepare what felt like endless FedEx shipments). I look forward to seeing how Snapshot continues to grow.

And for my teammates, if you have any bird identification questions in the future, let me know. You’ve got my number.

-Michael Kamp

January #SuperSnap

Swooping through the trees for our January #SuperSnap is this pileated woodpecker from Sawyer county. Pileated woodpeckers are the largest woodpecker species in Wisconsin, growing to almost the size of a crow. Despite their size, these birds are notoriously difficult to spot. Stay on the lookout for their bright red head crest, and keep your ears open for their loud drumming and high-pitched call.

A huge thanks to Zooniverse participant @JoyKidd for the #SuperSnap nomination!

Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.

Elk Camera Updates

Co-authored by Ally Magnin and Emily Donovan

You may have noticed recently on the blog that the Snapshot team has spent some time in the Northwoods conducting fieldwork in the elk grids. But what was our motive as researchers?

Wisconsin’s elk herds are dynamic and do not necessarily occupy the same area all the time.  Young individuals may temporarily disperse, cows split off from larger herds to give birth, and the herd as a whole may shift their range as they seek out suitable habitat. While this is to be expected, it creates an interesting problem for camera trap research.

A bull elk with antlers wearing an orange GPS collar

A bull elk from Black River Falls, WI with a GPS collar.

Since 2015, Snapshot Wisconsin has had a portion of our project dedicated to monitoring reintroduced elk herds. Cameras were deployed in grids much smaller than the usual Snapshot Wisconsin grid, increasing the density of cameras in the herd reintroduction area and making it more likely to capture photos of elk. As the herds shifted their range, however, some cameras no longer detected elk. To begin to address this mismatch between our elk grids and the herds’ ranges, Data and Spatial Analyst Emily Buege Donovan conducted an analysis.

Donovan began by combining several elk-related data sources to assess the quality of each camera site.  Among these data sources were the most recent GPS locations of collared elk. A portion of the state’s elk are fitted with GPS collars, which transmit a location every 13 hours. GPS collar data is commonly used in wildlife research and management to better understand the movement patterns and resource selection of animal populations. In the present study, Donovan used these data to predict the likelihood that a camera will regularly detect elk. See Figure 1 for an example of the camera locations in relationship to the collar data. Camera locations in the northwest portion of the map have low probability of capturing elk, whereas cameras in the southeast have a high probability of capturing elk photos.

A map of camera locations and GPS collar data

Fig 1. Example map of Snapshot Wisconsin cameras within the elk grids and the 2019 elk collar data.

However, because not all elk in Wisconsin are collared, the collar data could not be used exclusively to determine whether a camera site should remain active in elk monitoring efforts. Donovan also needed to bring in the historical elk detections for each camera site. How long had it been since an elk was detected at this site? How many elk photos were taken by each camera? By combining the collar data, photo data, and several other factors, such as ease of access by the volunteer and habitat type, Donovan created a scoring system to determine the best camera locations. Low scoring cameras were marked for removal, and high scoring cameras were marked to stay on the landscape.

Once we determined which elk blocks should be removed, we reached out to the volunteer who was assigned to each of those blocks and requested their assistance in removing the camera. For the blocks that didn’t have a volunteer assigned, our team planned fieldwork for the summer of 2020 to remove the cameras.

Snapshot Team Member Ally Magnin

Snapshot team member Ally Magnin during elk camera fieldwork.

Many of the cameras marked for removal were deployed over three years ago, so navigating to them proved difficult in some cases. We traversed tamarack swamps, bushwhacked through thick understory, hopped across streams, and puzzled over satellite imagery to reach each destination. Our team enjoyed the challenge!

In addition to removing old cameras, we also conducted camera checks on the blocks that didn’t currently have a volunteer assigned in order to get them ready for a new volunteer to monitor, and replaced cameras that had shown signs of malfunction. We made it a priority to take diligent notes about how to navigate to each camera site to make navigation easier for future volunteers.

Overall, it was a very productive field season that provided the team with the opportunity to step away from our computer screens and into the outdoors. It also gave us an even greater appreciation for the work our volunteers do to monitor their cameras.

Are you interested in monitoring a camera as a part of our elk project? Sign up today at elk.snapshotwisconsin.org. Applications are reviewed when blocks open up, and we will contact you with more information once you’re accepted!

Check out our other elk-related blog posts below:

Elk Snapshots Mean Better Elk Modeling

How Much Do Elk Antlers Weigh?

Elk Calf Searching

December #SuperSnap

Pictures of these two black bears from Lincoln County quickly captured the attention of our Zooniverse community. That’s why we deemed a photo of this pair our December #SuperSnap. Black bear cubs are born during January and February each year. The cubs remain with their mother for about 18 months. During this time, mother bears will teach their cubs how to climb trees, find shelter, and forage for food before sending them off into the world on their own.

A huge thanks to Zooniverse participant @momsabina for the #SuperSnap nomination!

Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.

November #SuperSnap

This playful coyote family from Rusk County has been deemed our #SuperSnap for November. Coyote parents are resourceful when preparing a den for their pups. Some coyotes will repurpose abandoned burrows from skunks, woodchucks, foxes, badgers, and even other coyotes to create a den. Female coyotes will also prepare several den sites that include multiple entrances for a quick escape if threatened by predators. 

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A huge thanks to Zooniverse participant @oregano for the #SuperSnap nomination!

Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.

Taking a Bite Out of Deer Aging

The age composition of a population can tell us a lot of useful information. In whitetail deer (Odocoileus virginianus), age data provides information about deer herd characteristics, harvest or mortality pressure on a specific age group, and general progress of a wildlife management program overall. A common way to age deer is through tooth wear and replacement. Let’s chew into this technique.

As a determined undergraduate, I voluntarily participated in a few of the DNR’s attempts to collect age and sex data of whitetail deer through in-person registration. Those data were collected from hunters pulling into the local gas station to show off (and ultimately register) their deer. Polite small talk was usually cut off by the sight of my clipboard, knife, flashlight, and jaw spreader. With a cheery smile I’d ask, “May we collect some information about the age and sex of your deer for management purposes?”. Most hunters gladly gave us the chance to examine their deer, but every now and then a trophy buck would pull in– and we knew better than to ask. Why? Because aging deer by tooth wear and replacement requires spreading (and sometimes cutting) the jaw and cheek to get a better look at the back teeth. In-person registration is no longer done, nowadays the DNR gets aging data from deer processors and CWD sampling.

A sketch of the side-view of a deer's jaw, labeled with molars, premolars, diastema, and incisors.

Illustration of the sideview of a whitetail deer’s jaw and teeth. Credit: WIDNR

Although aging deer from tooth wear and replacement has its limitations, it is the quickest and cheapest way to determine the age of a deer. It requires determining which teeth are present in the jawbone and how worn those teeth are. The data determine which of the following age classes a deer falls into: fawn (younger than 1 year), yearling (1-1.5 years), or adult (categorized as 2, 3, 4-5, 6-8, 9-11, or 12+ years).


Fawns usually have only three or four fully erupted teeth along each side of their jaw. The first three are temporary premolars and are often called “milk teeth”. Deer are born with these teeth fully erupted in place (unlike humans). It is important to note that the third premolar has three cusps. A deer with only three or four fully erupted teeth along the jaw is a fawn (Image A).

An illustration of the sideview of a fawn's jaw.

Image A. Example of a fawn’s teeth. Credit: Indiana DNR.


Yearlings are described as approximately 1.5 years old in the fall and generally have six fully erupted teeth on each side of the jaw. The third premolar is worn down by now but should still only have three cusps as it has not yet been replaced by a permanent tooth (Image B).

An illustration of the sideview of a yearling's jaw.

Image B. Example of a yearling’s teeth around 18 months. Credit: Indiana DNR.

At 18-19 months old the temporary premolars (first and second premolars) have been replaced by permanent premolars and the third premolar has now become permanent with only two cusps. A deer with six fully erupted teeth along the jaw is a yearling (Image C).

An illustration of the sideview on a yearling's jaw.

Image C. Example of a yearling’s teeth after 18-19 months. Credit: Indiana DNR.


Adult deer are 2.5 years and older. They will have six fully erupted teeth along each side of the jaw: three permanent premolars and three permanent molars. At this point, it is no longer as simple as counting the teeth and cusps. It is going to take a sharp eye to observe the amount of tooth wear on the teeth. Over time, teeth wear down increasing the width of the dentin exposed along each cusp. Deer older than yearlings are aged through wear of the cusps closest to the tongue on the cheek teeth. For 2.5 years and older, the third premolar is stained. The fourth tooth shows little wear, having a distinct point, and the dentine is thinner than the white enamel. As the deer ages, the cusp points will be worn down and the teeth will become relatively flat (Image D).

An illustration of the sideview of an adult deer's jaw.

Image D. Example of an adult deer’s teeth. Credit: Indiana DNR.

By no means am I an expert in aging deer. As you may now understand, learning how to age deer using tooth wear and replacement is not a one-day deal. Like everything, it takes practice. While we only took a bite out of deer aging, years of training and practice can allow researchers (and undergraduate volunteers) to age a deer down to the exact year. As mentioned, using tooth wear and replacement isn’t the most accurate technique for aging deer, but it is the most hands-on (and fun) approach.





October #SuperSnap

This month’s #SuperSnap goes to the slick pair of North American River Otters featured below from Vilas County. Otters are known to produce slide marks as they move their bodies along ice, snow, and mud on the edge of riverbanks. As the only species in the state to produce these distinct tracks, the Wisconsin DNR performs a series of aerial surveys in the winter to search for the presence of otter slide marks. This data is then incorporated into population estimates for the species. 

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A huge thanks to Zooniverse participant @Megeth for the #SuperSnap nomination!

Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.