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Fall 2020 Wildlife Survey Story-of-the-Day

posted Oct 9, 2020, 10:46 AM by Jonathan Poppele   [ updated Oct 9, 2020, 10:46 AM ]
Our Fall Wildlife Tracking Survey took place this past October 3 at the Carlos Avery Wildlife Management Area. Eight members of the Minnesota Wildlife Tracking Project gathered to survey the sandy roads or Carlos Avery, just a few miles from our regular survey location at Cedar Creek Ecosystem Science Reserve. While we only found clear tracks of a few species of mammals, they included footprints we had never seen in the filed. We also may have verified a species we had never confirmed at Carlos Avery before. Here is our story of the day.

Our group divided into two tracking teams for the day. One team walked a loop around Pools 6 & 8, focusing attention on an old sand pit just off Wyoming Rd. dubbed “Peaceful Canyon” by our friend Blake Southard. The other team followed South Rd into the southern extension of the WMA, just across Co Rd 18 from the DNR headquarters.

The dirt roads through Carlos Avery provide a mix of substrate ranging from hard, gravely soil to soft sand. There are natural track traps along most roads, but many of these areas get regular traffic. With duck hunting season in full swing, there were few clear tracks along the roads. Digging sign from fossorial mammals along the edges of the roads, however, abounded.

Both of the teams noted large, fresh pocket gopher mounds and mole runways. The greater Twin Cities Metro Area is home to only one species of Pocket Gopher—the Plains Pocket Gopher (Geomys bursarius)—so we can identify these mounds with confidence. Two species of moles are found in the area. The Eastern Mole (Scalopus aquaticus) and the Starnosed Mole (Condylura cristata). Starnosed Moles are weaker diggers than Eastern Moles, are most common along the edges of waterways, and rarely push up the kinds of prominent runs we were finding. We can safely identify most of these runs, many of which were extremely large, as having been made by Eastern Moles.

Many of the pocket gopher mounds we found had tunnel openings in them. Some of the mole runs we found showed openings in them as well. Pocket gophers typically plug their tunnel entrances to maintain consistent humidity and deter predators. Most times of the year, it is rare to see open tunnels in pocket gopher mounds. On this occasion, however, they were quite common. Do pocket gophers have a different set of needs at this time of year? Are these open tunnels related to dispersal? Are they the work of other species, such as voles, making use of the gophers tunnels?

The open mole tunnels were their own mystery, and also offered a rare treat. On the two-track road leading into Peaceful Canyon, one team found a mole runway so shallow that it was an open trench rather than a tunnel. And on the floor of the runway were the clear tracks of an Eastern Mole. Unlike species such as the Hairy-Tailed Mole (Parascalops breweri) which regularly come to the surface to forage in leaf litter, Eastern Moles are almost completely fossorial and may spend their entire lives underground. Eastern Mole tracks are quite rare, and none of our trackers had ever seen them in the field before. As far as we know, these are the only photographs of Eastern Mole tracks on iNaturalist, or anywhere in the tracking literature. 

And these weren’t the only surprising tracks our teams found at Carlos Avery. One team returned with a photo of a single large canine print from a sandy roadside. It was an isolated tracks. The rest of the trail had been covered over by human traffic. But it was tantalizing. The print measured 3 3/8” long and 2 1/2” wide, with a star-shaped negative space. It is always difficult to identify a large canine to species based on a single track. Carlos Avery is a popular spot for dog walkers, and canine tracks in the WMA are generally best considered “domestic dog until proven otherwise.” In this case, we had something to compare the track to—field drawings of the hind track of the wolf our team had been tracking at Cedar Creek for the past few years, prior to the pandemic. Not only is the size of this track an exact match, but specific shape of the palm pad is as well. While it is possible, at least in principle, that there is a domestic dog with a rear palm pad that has the exact proportions of the wolf we have tracked at Cedar Creek, it is highly improbably. If we found this track at Cedar Creek, I think none of us wold have any doubt that it was from our local wolf. Cedar Creek is only about 10 miles away from where this observation was made, and is connected by nearly unbroken stretches of woods and wetlands. So this shouldn’t be a huge surprise. But this is the first time we have gotten a strong indication that the wolf is ranging into Carlos Avery. It also appears to be the first track from this animal we have recorded since last winter.

There were other sightings throughout the day as well. We identified some animal remains, such as this meadow vole and this red-bellied snake who were unfortunate victims of cars. Our teams also found the tracks of three species of squirrels and were able to take a deep dive into the sometimes subtle differences between the tracks of chipmunks, red squirrels and gray squirrels. Some of these observations also offered a reminder to us in the value of multi-factor analysis. One of the chipmunk trails we found measured 3 3/16” wide, which is wider than any of the published ranges for chipmunk trails. Elbroch lists 2 7/8” as the upper limit. But the track size and foot morphology were distinct. Apparently they grow ‘em big in Carlos Avery.

You can see all of our observations from the day here on iNaturalist.

Our Fall Survey is the last wildlife survey for 2020. We are holding off on scheduling or 2021 dates until we have a better understanding of when normal operations will resume at Cedar Creek. Stay tuned for future announcements and keep an eye on the calendar. We hope you can join us for a future survey.