Today Derek and I headed out to Sauk County to look for some birds, reptiles, and insects at one of the most unique environments in the state: Spring Green Preserve. Spring Green is located in the south central part of the state and is one of the most arid places in the state. “Wisconsin’s Desert” is complete with sand, cacti, and numerous flora and fauna that are found nowhere else in the state.
We made the two hour drive and arrived a little after 7 am. We were immediately greeted by swarms of small insects buzzing around our faces. For the early part of the morning the small gnats and flies were nearly insufferable but we pressed on. We heard several loud calls coming from the Prairie as we broke the thresh hold between the parking area and the preserve. The preserve itself is relatively small with only one trail that leads from the lot into the large ridges that prevent moisture from getting to the sandy ground. One call that stood out was that of the Dickcissel. This has been a good year for the species and Spring Green is perhaps one of their greatest strongholds in Wisconsin. It seemed like every short tree and shrub had a Dickcissel on top.
If not a Dickcissel on a particular tree top it was a Lark Sparrow. Lark Sparrows can be found in other counties but they are more seldom reported. At Spring Green they are extremely numerous. This gave us a great opportunity to watch some of their behavior. The sparrows were constantly chasing each other from tree to tree and gathering large grasshoppers and other insects. There was even one Lark Sparrow that nonchalantly hopped on the trail just a few feet ahead of us gathering insects and acting oblivious to our presence.
One other very loud species on the Prairie was the Grasshopper Sparrow. These sparrows earned their name from their insect-like buzzing noise they make as well as the fact that they grasshoppers make up a large portion of their diet. Grasshopper Sparrows belong to a group of elusive sparrows known as Ammodramus Sparrows. This group of birds likes to skulk in tall grasses and other plants. They are often difficult to find, but these Grasshopper Sparrows perched up very nicely for us to view.
After a while we were joined by Rob Pendergast and continued searching. By the time Rob arrived a nice breeze had picked up over the preserve and a lot of the insect activity had subsided. We walked back the same way on the trail we had paced back and forth on earlier and came across one of the local reptiles: a Blue Racer. Blue Racers are among the fastest snakes in North America. They can be found in prairies and Oak Savannas in the western half of the state. This one was lazily slithering near the trail and eventually climbed a small tree.
Also present near the same area was another quick reptile: The Prairie Racerunner. Much like the Blue Racer, these lizards have incredible speed (up to 18 mph.) We found them quickly running across the sand trail and sunning themselves on rusted sheet metal.
As we walked the trail we picked up some other bird species that call the preserve home. An Indigo Bunting sang loudly from the largest dead tree in site and Orchard Orioles created a chorus along with Rose-Breasted Grosbeaks on both ends of the trail where more trees were growing. Many other common birds such as Mourning Doves, Robins and Blue Jays were in the area as well.
Having thoroughly searched for all avian activity in the area, we turned our attention to some unique invertebrates. Spring Green is known by a proud few for its Tiger Beetles. Nine (possibly 10) species of this small but veracious predatory insect make Spring Green their home. We were able to find three species of them. The Oblique-Lined, the Festive, and the Big Sand. They would fly and sometimes run along the path we were walking. Much like everything else we encountered, the Tiger Beetles are extremely fast movers. So fast in fact that while they run after their prey they go temporarily blind until they stop moving.
In all, we were pleased with out day in the desert. We missed out on two rare birds that were reported recently (Blue Grosbeak and Northern Mockingbird), but seeing the other interesting birds, reptiles, and insects made the trip well worth it. It’s not everyday we get to explore such a unique ecosystem in our home state.