Snapshot Wisconsin March 2025

Early last month, Punxsutawney Phil proclaimed 6 more weeks of winter. For Snapshot Wisconsin that means now is the perfect time to share trail camera tips for the final weeks of winter, discuss the new ways Snapshot will be able to monitor winter data in the future and highlight one unique way Snapshot volunteers have contributed to another ongoing DNR project this season. Additionally, find a cozy spot and read along as we take a deeper dive into one of the most recent publications that utilized Snapshot data, Fractional Richness: An Index for Trail Camera Networks.

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Fractional Richness: A Closer Look

Take a deeper dive into one of Snapshot's most recent publications, Fractional Richness: An Index for Trail Camera Networks.

Tips for Cold Weather Camera Check

The end of winter can be unpredictable. Here are our tips for the rest of those chilly trail camera checks.

Snapshot Volunteers Aid Bear Research

Snapshot volunteers have contributed to Wisconsin bear research in a big way. Read more to find out how!

Snapshot Wisconsin Collaboration to Receive NASA Grant

Learn more about this new funding opportunity and how it could shape Snapshot Wisconsin moving forward.

Fractional Richness: A Closer Look 

In Snapshot’s October newsletter, we announced the release of a new publication, Fractional Richness: An Index for Camera Trap Networks, that utilized Snapshot Wisconsin data to develop its findings. Although key takeaways were recapped in the previous newsletter, a more holistic understanding of them warrants a closer look at this complex study’s finer details.

Understanding Traditional Diversity Indexes

Trail camera networks are an effective way to monitor wildlife year-round and can provide vital information when considering management decisions. This publication’s focus was on how these trail camera networks can most effectively measure wildlife diversity. Traditionally in ecology, wildlife diversity has been assessed by utilizing measures such as “species richness”, “species evenness” and “Shannon diversity”. 

Species Richness is the total number of different species in an area. For example, the species richness of the animals grouped below would be three.

Species Evenness refers to whether the species in a given area have similar abundances. A basic representation of an even and uneven community can be seen below. 

Shannon Diversity is an index that incorporates these measures of richness and evenness and uses them within a formula to assign a diversity value to an area. The result is a numerical value, with higher numbers implying higher diversity.

The primary issues with these traditional diversity measurements related to trail camera data are twofold:

1. They struggle to account for differences in the detection of different species.

Ex: The chance of seeing a white-tailed deer on a trail camera is different than the chance of seeing a mouse. So, if you spot a deer on your camera, but no mice, that doesn’t necessarily mean mice are absent from the ecosystem as they could just be harder to detect.

2. Species evenness and Shannon Diversity, equate, sometimes incorrectly, more equal species abundances with higher diversity.

Ex: Take a look at the figure below. The graph on the left represents real data pulled from Snapshot Wisconsin’s trail camera network. However, when the data is manipulated to depict the loss of a common species (in this case, deer in the graph on the right), the Shannon Diversity index incorrectly rewards more similar abundances (i.e., evenness) and gives a higher diversity score. 

To improve these species diversity estimates for trail camera data, we present Fractional Richness. 

What is Fractional Richness?

Fractional Richness, like Shannon diversity, is an index where a higher value equates to greater diversity. However, it is unique in that it requires multiple sites (i.e. multiple camera locations). Additionally, instead of using a measure of evenness to compare species’ abundances against one another, Fractional Richness measures the abundance of a single species at one location and compares it to that same species’ abundance at all other locations. 

Take a look at hypothetical trail camera detections below. If site D had been the only sample location, evenness would tell us that because the mouse and deer detections are equal, this area has high diversity. However, if you look at the average and maximum detections of those same species across all camera locations, you can see that at Site D detections for both species were actually lower than the average. Similarly at Site B, though uneven, both species are still quite close to their respective detection averages. These relative differences in detection between species are what Fractional Richness takes into account, making it a preferable diversity metric for trail camera data. 

Testing Indexes with Snapshot Wisconsin Data

Animal detections from 2,218 Snapshot Wisconsin trail cameras were used to calculate Shannon Diversity and Fractional Richness for two animal communities: human-sensitive species (primarily in the northern region of Wisconsin) and human-associated species (primarily in the southern region of Wisconsin). Creating two separate groups helped researchers account for inherent regional differences due to things like habitat availability and climate. 

*Turkeys and white-tailed deer did not show a strong correlation to either group and were not included

Researchers ultimately found that the human-sensitive community in northern Wisconsin had much higher species evenness (i.e. more equal abundances) than the human-associated community in southern Wisconsin. Because of this, both the Shannon Diversity and Fractional Richness model predictions were equally accurate in the even community (north). However, in the uneven community (south), Fractional Richness performed better.

Three key takeaways from this work are:

• Equating species evenness to higher diversity in an ecosystem can cause inaccuracies when using the Shannon Diversity index.
• Because the Fractional Richness index utilizes multiple sample sites to calculate its diversity value, it can help compensate for species that may have lower detection on trail cameras.
• When utilizing a trail camera, data Fractional Richness may be a more accurate index to estimate diversity.

Looking forward

It is a direct result of the hard work and dedication of the Snapshot Wisconsin community, that we can provide data to cutting edge studies like this one. Projects like these and their findings are constantly improving our ability to effectively monitor wildlife and make a real difference on a broad scale. As Snapshot Wisconsin continues to evolve, we look forward to finding additional pathways in which we can contribute to innovative science and best support wildlife management efforts.

Tips for Cold Weather Trail Camera Checks   

On a lighter (but chillier) note, it’s that time of year again! While spring is in sight, birds are still South for the winter, bears are in torpor, and deer have grown their thick coat – Wisconsin’s cold season is in full swing. We have gathered some tips that you should consider before heading out in the cold for your next camera check.

1. Wear Warm Layers – Whether you have a short or long walk to your trail camera, you should always layer up when it’s cold outside. Having a base, middle and outer layer is your best bet to keep your body warm. Even if you don't wear all three layers, it's a good idea to take all layers on every outing: You can peel off layers if things heat up, but you can't put on layers that you didn't bring along. Don’t forget a good winter hat, gloves, and hand warmers too!
2. De-icer for Padlocks – If moisture gets inside the padlock and freezes, spinning the numbers can be difficult or impossible with fingers alone. Deicer is a great tool to have when the lock just won’t budge. Use as directed and the dials should go back to spinning normally!
3. Waterproof Boots – Melted snow, recent rainfall, or areas that are naturally wet may “dampen” your overall camera-checking experience. If you have a pair of waterproof boots or thick socks, you may want to consider bringing these along! Soggy shoes are never fun, especially in below-freezing temperatures.
4. Brush Away Snow and Ice – Make sure to brush away any accumulated snow and ice around the camera the best you can. Any excess moisture on the camera could potentially lead to camera malfunctions when the snow and ice melt. The screen may not work, the battery terminals could rust over, or moisture could get into the lens causing the photos to look bad.
5. Budget Your Time – Even if you think that your hike to your camera will only take thirty minutes, budget some wiggle room for inclement conditions. If you know you won’t have cell phone service in the woods, tell a friend or family member of your plans – this may include where you are parking your car, your intended route, what time you expect to be back, and what time to take further measures if you don’t return by. It’s easy to underestimate how long a camera check may take in the winter.
6. Double Check Your Coordinates – Sometimes your phone and your personal GPS will tell you to go opposite directions, and you will find yourself circling around a swamp for thirty minutes. It never hurts to double-check your GPS coordinates before venturing into the woods, especially if it’s cold outside.

Snapshot Volunteers Aid Bear Research   

Looking for another way to contribute to science this winter? Many Snapshot volunteers already have! The DNR’s Black Bear Litter and Diet Survey is an ongoing project that seeks to estimate bear reproductive rates within management zones, improve the accuracy of state population models and inform bear management decisions. To ensure a strong model, however scientists need to survey many dens each winter and the public is often the best resource for receiving location reports!

We’ve recently heard from our colleagues in charge of this project that they have gotten a number of den reports that cited Snapshot Wisconsin as being how they learned about the study, which is awesome news! Although peak denning season is winding down, there are still a few weeks left to report a known den if you haven’t yet. We appreciate all the support so many of you have already shown for this project, it just goes to show what great things this community can accomplish together!

Snapshot Wisconsin Collaboration to Receive NASA Grant     

In May of 2024, Snapshot Wisconsin joined researchers from the University of Wisconsin’s Department of Forest and Wildlife Ecology to apply for funding from NASA’s Citizen Science for Earth Systems Program (CSESP).  Snapshot is now happy to announce that the grant was received and will allow this collaboration to pursue some exciting new research!

The question behind this new research is simple, how can citizen science projects like Snapshot contribute to a better understanding of how wildlife is changing and responding to the seasons? To help answer this question, NASA’s funding will be able to provide researchers with several things:

1. Snow stakes – Snow stakes, pictured below, are marked poles used to record snow depth. These poles will be placed at approximately 300 Snapshot Wisconsin trail camera sites, with the aim that the cameras will pick up and record the changing snow depth.

2. Temperature logs—Intended to function year-round, these devices will be placed alongside the cameras recording temperature changes.
3. Audio Recording Units (ARUs) – ARUs help to capture the sounds of animals that might not necessarily be visually captured by a trail camera, for example bird songs or amphibian vocalizations. 

All of these tools will help researchers capture the broader picture of biodiversity within ecosystems and better understand the relationship between seasonal changes and wildlife. The data will be analyzed by researchers at UW, who will help to determine the project’s more specific research questions, exact protocol, and how the locations for these additional tools will be chosen. 

The broader implementation of this new project will likely roll out next year. But for now, researchers from both programs have already begun to prepare. Recently, a small pilot program began with 24 snow stakes deployed by volunteers across Wisconsin. This small trial run will allow for the testing of proposed setups, fine-tuning protocol and the chance for program leads to hear feedback from the volunteers involved.

Once researchers better understand these variables, Snapshot will reach out more broadly with information on the full implementation plan. Additionally, once the rollout begins, volunteers can also look forward to immersive Snapshot events such as data analysis workshops where new data will be reviewed and interpreted alongside the project’s lead scientists. 

We’re so excited about this next chapter and grateful for every Snapshot volunteer’s continued support of this project. We look forward to keeping you informed and can’t wait to see what great discoveries lie ahead!