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Post date: Aug 10, 2019 11:9:4 PM
On July 13, our team of 15 trackers and naturalists spread out along the roads of Cedar Creek Ecosystem Science Reserve for our fourth Summer Survey. We have come a long way since our first survey on August 7, 2016. In the past three years, over 100 people have participated in one or more of the thirteen surveys we have done at Cedar Creek. Our core group has grown and developed--both in numbers and in skill. Some of our earliest volunteers, such as Kari Skoog and Mark Erikson, have taken part in nearly every survey and are now helping to lead our teams in the field.
For our Summer survey, our group divided into three teams and explored the North Unit, the area around Lindeman Lab, and Old East Bethel Blvd along the western edge of the bison enclosure. The largest surprise of the survey was the modest diversity of mammal tracks our teams found. Unlike some past surveys where we have recorded the presence of as many as thirty species of mammals, our teams verified the activity of just nine this time around: coyote, red fox, raccoon, white-tailed deer, eastern grey squirrel, eastern chipmunk, plains pocket gopher, mole, and shrew. We saw no signs of bears, skunks, weasels, cats, other squirrels, large rodents, rabbits or mice. Significantly, for the second survey in a row, we also did not see any signs of wolves.
It's good to remember that while our surveys can verify the presence of a particular species on the landscape, it is more challenging to interpret what the absence of sign means. We can only record what we find, and what we find depends not only on where we choose to explore, but also the weather, seasonal variation in animal behavior, and the substrates available to us. Our teams regularly find fisher tracks in our winter surveys, but have yet to verify any during the summer. But it seems unlikely that the fisher leave the reserve in the summer months--they just don't use the roads much. There are about as many bears, skunks, weasels, cats and so forth on the property now as in previous seasons. We just didn't happen to see their tracks or sign this time out. But in the case of the wolves, we may be able to read a bit more into our observations. Wolves make heavy use of the roads, and frequently mark road/trail junctions. They also affect the behavior of other animals in dramatic ways. Up until this spring, our teams had found wolf tracks or scat on every single one of our surveys. We have now had two surveys in a row where we haven't seen any. Together with this, the behavior of the coyotes seems to be shifting in the North Unit in a way that suggests there are no wolves in the area. At least for now, it appears that the wolves have left Cedar Creek.
Our team in the North Unit followed the main road in from Gate 7 and up past Field A. From right inside the gate, the team found the tracks deer, red fox, and coyote using the road. The deer and red fox were a familiar sight, but the coyote have been scarce along this roadway in the past. Only recently have we seen coyote tracks along the road. And in each of our past three surveys, they have become more numerous, moved more comfortably in the open, and extended farther from the edge of the property into the area where we had seen the most wolf sign in the past. Interestingly, though the coyotes were clearly making their presence much more known, the red fox did not appear to be shying away from the open--at least not yet. The boldness of the coyotes along the teams entire survey route strongly suggests that the wolves have moved on.
Besides the deer, fox, coyote, and ubiquitous pocket gopher mounds, the only other mammal sign the team found was a lovely set of grey squirrel tracks in mud, just past the edge of the woods. But there was plenty of other diversity in the North Unit to pique our naturalists's interest including toad tracks, a tiny wood frog, a beautiful Arabesque Orbweaver, and Summer Azure butterflies feeding on an old coyote scat.
In the area around Lindeman Labs, fox and deer were the order of the day. On the trail between Lindeman Lab and Cedar Bog Lake, our team found the tracks, scat, digs, and scratches of several red fox. The tracks included a range of sizes, suggesting a mom and kit hunting along the road together. South of Lindeman, the team found more fox tracks along with larger canine tracks which were likely coyote, but not clear enough do distinguish from domestic dog with certainty. Dogs are not permitted in the reserve, but our tracking surveys and the Eyes on the Wild trail camera network have both shown that they do come onto the property.
Our third team spent their time on Old East Bethel Blvd, along the western edge of the bison enclosure, with a focus on following coyote trails and exploring how the enclosure might affect their movement. The team followed the trail of a large coyote north along the road, and spotted the tracks of others in the bison wallows just inside the enclosure. The trails they spotted in the wallows mostly paralleled the road. They also found some coyote trails crossing East Bethel at points where it was easy to pass under the fence. It is clear that the coyote are very comfortable and established in this part of the reserve--and seem perfectly home among the bison.
In addition to the coyote trails, the team also found the trail of a bullsnake, some chipmunk, squirrel and raccoon tracks, and a variety of bird tracks including mourning dove, American robin, ring-necked pheasant, and turkey and sandhill crane, which our trackers are now distinguishing with confidence.
As always, our survey left us with more questions than answers. Primary among these, of course, is where are the wolves? The last time we saw evidence of them was during our winter survey when one team trailed a wolf for a couple of miles, found a kill site, and verified the presence of two different individuals. Where are they now?
Also, while it is not unusual to have a survey where we don't see any sigh of bear or skunk or weasel or cat, it is unusual to not see any of these carnivores. Was this just by chance? Or are there patterns to these animals movements that had them away from the roads we traveled at this time of year?
Many of our trackers are becoming increasingly interested in and aware of bird tracks. But there is little information available about how to distinguish the tracks of most of the birds we find at Cedar Creek. How can we build our knowledge of these small bird tracks? And given that birds, unlike many mammals, can often be seen and heard, is there scientific value in our learning to identify small bird tracks with confidence? There is no question that it is fun and enriching!
We will have a chance to explore these and other questions at our special two-day fall survey on September 21-22. I hope you can join us for one or both days. Full details coming soon.
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