Highlighting Sandhill Cranes on the Data Dashboard

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

Continuing with the bird theme, the Snapshot Team wanted to highlight one of the five specific species that can be chosen while classifying photos: the sandhill crane. At the same time, the team wanted to use the new 2020 data on the Data Dashboard, so they decided to do both!

The team invited fellow DNR researcher, Jess Jaworski, Assistant Waterfowl Research Scientist within the Office of Applied Science, to look through the sandhill crane data on the Data Dashboard. Jaworski is currently working on waterfowl research, but she previously worked with cranes.

Jaworski’s graduate research involved studying the nesting behaviors of cranes in Wisconsin. “My graduate research was focused on the nest success of the reintroduced whooping crane population at the Necedah National Wildlife Refuge. The majority of my work was monitoring incubation behaviors of both whooping cranes and sandhill cranes under duress of an avian-specific black fly. This fly caused a wide-spread and synchronous abandonment of nests.” Jaworski put up several trail cameras at nests and went through thousands of photos to monitor behaviors at those nests; Not that different from what Snapshot Wisconsin does.

A group of sandhill cranes in Jackson County.

A Bit Of Background On Sandhill Cranes

Before we dive in, let’s make sure everyone knows a bit about sandhill cranes. Jaworski was happy to share her knowledge of sandhill crane behavior.

Wisconsin’s sandhill cranes are part of the Eastern population of migratory sandhill cranes, and there are over 70,000 individuals in this population. As implied by the term “migratory,” they don’t spend the entire year in Wisconsin. Jaworski explained that these birds spend the winter down South. Around mid-March, they come back north to their breeding grounds and establish pair bonds.

Sandhill cranes are typically a monogamous species, so they will find a mate and pair off if they don’t already have one. “They usually try to find a pair bond within up to two years of birth, and they start nesting at three to six years in open marsh wetlands, although sandhill cranes can nest in a wide variety of habitats. They hopefully will hatch within a 28-day incubation period and fledge their young within two to three months. Once that is done [usually in September/October], they migrate back to their wintering grounds.” Come the next March, they start the cycle over again.

A map from the Snapshot Wisconsin Data Dashboard showing the percentage of trail cameras that sandhill cranes were observed on.

Diving In To The Data Dashboard

Jaworski was curious how well the trail camera data would match the description she gave above. The team sat down with her to see. At first glance, Jaworski said the data seemed pretty consistent with what she knows about their behaviors and where cameras were located around the state.

Take the map of detections by county, for example. Jaworski pointed out a higher percentage of crane detections in the southeast quadrant of the state. “That is consistent with their habitat [preferences]. They typically nest in open marshes, and the map matches where I know wetlands exist in the state,” said Jaworski. “Dodge County has cranes in the Horicon Wetland Area, for example. To the northwest, there are more cameras picking up these birds, potentially from the Crex Meadow Area. There is a large amount of birds in Adams County nearby to Juneau County where birds nest at the Necedah National Wildlife Refuge, which is where I did my graduate work.”

Jaworski also looked at detections by the ecological landscape, a clickable option to the left of the map. Instead of counties, the map is blocked out into 16 regions with unique ecological attributes and management opportunities. “Generally, the southern and eastern sections of the state have more open, wetland areas, so I’m not surprised there are more detections in those areas. There are also a lot of agricultural fields here too,” said Jaworski.

“Sandhill cranes can adapt easily to human-made landscapes like agricultural fields, and it isn’t uncommon to see them nesting in smaller wetlands near agricultural fields, for example. If there are a lot of cameras in these areas, then there will be more sightings of sandhill crane.” In contrast, the northern part of the state tends to be more forested land, so the southeast is the ideal habitat for a crane looking to build a nest.

Activity By Month And Hour Of The Day

So far, the detection locations matched what Jaworski expected to see, but one of the more interesting features of the dashboard is the breakdown of detections by month and by hour of the day. How well would the data hold up?

Jaworski started with the month data and immediately zeroed in on the lull in detections during the winter months. “This is exactly what I’d expect to see,” said Jaworski. “These migratory cranes are down south in their winter grounds [during these months]. When you get to March and April, I see a heightened activity pattern from cranes migrating back and nesting. Then, there is a lull again later in the year, as they start migrating back south.”

Jaworski also noticed that the migration south occurs over a much longer period of time than the migration back, as seen by a more gradual decline in detections in September and October. “That could be a product of different nest initiation times or different successes/failures throughout the nesting period. If birds nested earlier, then they will have fledged their young earlier than others and potentially leave the state sooner.” Alternatively, pairs who failed to successfully rear a fledgling may start over again if there is time. These pairs wouldn’t be able to migrate as early as pairs who succeeded on their first try, and that may lead to more detections later in the year.

The Snapshot team discussed how the placement of cameras also can influence the detection of species like the sandhill crane. Not all species spend their time in areas that are easy for trail cameras to watch. Not many Snapshot cameras overlook the center of a lake or marsh, which can lead to biases in detections for certain species.

However, Jaworski did confirm that cameras set up near-ideal nesting habitats will be much more likely to detect cranes. Cranes can be seen while they are up and about from their nests, looking for food, or when adults swap who is incubating their nest.

Jaworski also looked at sandhill crane activity throughout the day. “In the morning hours, they will leave their roosting areas. When pairs are forming pair bonds, they will do dawn unison calls. You can often hear them in the early morning hours, [and the calls are quite distinct]. Throughout the day, they are probably feeding and moving about the wetland, so detections are more common then. In the evening, they return to their roosting site for the night.”

All in all, there were pretty clear patterns in the activity graph, and those patterns match what Jaworski expected to see. There is a small amount of variation between the hours of the daytime, but Jaworski didn’t think those peaks and valleys represented any meaningful behaviors for sandhill cranes. Jaworski said, “It is hard to determine fine-tuned patterns throughout the day. It could simply be from a bias in where the cameras are placed.”

The 2020 Data Are Accurate And Consistent

Jaworski and the Snapshot team adjusted the date slider in the left-most column of the dashboard to look at only the 2020 data. The 2020 data showed all of the same patterns that we’ve already mentioned and is consistent with what we know about where cranes are distributed across the state. “It shows that there is nothing unusual about this past year that indicated sandhill cranes are moving from their range or aren’t where you would normally see them occur,” said Jaworski.

Jaworski played around with the date slider some more and looked at each of the other years’ data individually. She noticed that the number of detections increased each year, starting from 2017. “It is really cool that detections are increasing. It says that interest in the program is also increasing,” said Jaworski. “Snapshot’s expansion each year provides more information about where these birds are located. Each year, you will find more detections, which helps inform research for this species. I also really like that there is a record of that data so that we can go back and analyze it if any questions arise in future studies.”

Jaworski’s Parting Thoughts

Before everyone parted ways, Jaworski shared some final thoughts with the team about the program and its impact.

“It’s wonderful that a program like Snapshot exists. If somebody is interested in knowing what is going on with a particular species, it is awesome that Snapshot allows people to find that information through the Data Dashboard. It is a great opportunity for people to get involved.

Additionally, that type of cooperation between researchers and those who aren’t in research is invaluable and helps inform [our] research. Its great from a research perspective and a curiosity perspective when we collaborate.

Plus, getting involved [in citizen science] can spark an interest in a science career! A lot of us in research didn’t initially start out that way. Many of us started out as citizens who observed something interesting or maybe as kids who tagged along with our parents while they were doing outdoor activities. Looking at species or finding out what a scientist did inspired us.

My family comes from a natural resource background. My dad started out as a forester, and my mom worked as a park ranger and a boating officer in New Mexico. I tagged along with my mom quite often when she was giving presentations at the nature center. We were outside recreating a lot, camping and fishing. It had a big influence on my life and my career choice.”

Jaworski encouraged more people to check out the Data Dashboard and learn something new about one of the species available. The Snapshot team suggests looking at the data in a similar way to how Jaworski did, piece by piece and thinking about what a species might be up to in different areas and at different times. It is a great way to think about the lives of these species. Plus, with the addition of the 2020 data, there is more data than ever to look at.