June 2019 Natural Mystery

posted Jun 11, 2019, 8:18 PM by Jonathan Poppele   [ updated Jun 11, 2019, 8:18 PM ]

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Bemidji Track & Sign Evaluation with David Moskowitz

posted Jun 11, 2019, 8:17 PM by Jonathan Poppele   [ updated Jun 11, 2019, 8:18 PM ]

Over the weekend of May 11-12, the Minnesota Wildlife Tracking Project's new Bemidji Chapter hosted David Moskowitz for a CyberTracker Track & Sign evaluation in the north woods.

Over the two-day evaluation, Moskowitz asked us a wide range of questions covering the tracks and sign of fourteen different species of wild mammals and seven species of birds. Some of the highlights included flicker scat, jumping mouse tracks, bear bites, wolf scat, an otter feeding station, and pocket gopher eskers.

Like all the CyberTracker evaluators, Moskowitz is a masterful teacher and has a tremendous wealth of knowledge. He shared with us tiny details of foot morphology, principles for interpreting sign, behavioral characteristics, and points of his philosophy on tracking. He also welcomed and drew out the knowledge from our diverse group. As a result, our debrief conversations were tremendously rich and everyone, including David, learned a great deal over the weekend. A couple highlights from Moskowitz teaching included:

Pocket Gopher Eskers
Approaching animal sign by asking three questions. First, if I had a toolbox, what tools would I need to produce the sign I am looking at? A chisel? An awl? A pair of sheers? Second, what animals come “equipped” with that kind of tool in the right size for making this sign? Finally, what behavior from these animals makes a coherent story to explain the sign I am seeing? Using this approach, some of us were able to decipher sign we had never seen before during the evaluation.

Keep in mind the differences between front and hind track morphology when thinking about key features that distinguish particular species. The narrow profile and “dot with wings” heel pad of a coyote, for example, are features of the hind track, not the front. Sometimes we remember key features of a particular species tracks, but apply them without distinguishing front from hind feet.

In addition to the questions on the evaluation, our group of trackers and naturalists found time to share knowledge and experiences and even add a few of our own conversations beyond those for the evaluation. Mark Fulton shared his keen eye for porcupine sign, regularly pointing it in the woods during our two days in the field. Sue Mansfield helped us understand some of the details and nuances of the bear trail and bear bites we found (you can tap into some of Sue's expertise about black bears here and here). Kim Shelton found the bounding trail of a small animal along the side of the road which looked at first glance to be the tracks of a small rabbit. After a bit of discussion in the group, we concluded they were the tracks of a thirteen-lined ground squirrel—an analysis that Moskowitz confirmed.

At the end of the day, eight trackers received certification in Track & Sign interpretation. The highlight was our host Kim Shelton receiving her Level IV Track & Sign certification--an impressive achievement and a well deserved acknowledgment for one of the most knowledgeable and experienced wildlife trackers and naturalists in the state.

We are looking forward to many more projects with the new Bemidji chapter of the club. Keep an eye out for a wildlife survey in that part of the state, as well as Minnesota's first Track & Sign Specialist evaluation!

Until then, there is still one spot remaining for our final Track & Sign Evaluation of the year with Casey McFarland over Labor Day Weekend. For more information, Contact Us.

May 2019 Natural Mystery Answered

posted Jun 4, 2019, 6:17 PM by Jonathan Poppele   [ updated Jun 4, 2019, 6:22 PM ]

Our May Natural Mystery was an unusual trail--wet footprints on asphalt. Though little detail is visible, a number of you puzzled this one out and correctly interpreted what happened here. Congratulations to Leah, Kim Cabrera, Brendan White, Amy Jacobs and Sandy Reed who correctly identified the sign and the species that left it. And a special congratulations to Shelly Montana who not only identified the species, but also deduced the exact circumstances of the tracks being made! I'll let Shelly take it from here:

I see the wet tracks starting at bottom of the photo, the animals stops when first entering the road as I see 2 drip marks behind the 2 round side by side tracks. I believe these to be front tracks. They seem too round to be coyote.The animals then walks as it takes a few steps, stops and shakes off the water. This produces a good bit of water left behind. The animal also seems to wander in the style of a drunk. Maybe sniffing the road as it’s crossing. This is not the sign of a wild animal as they usually move in straight line from point A to Point B. I believe this to be a Domestic Dog. Also the area is a rural, and a residential area. This is also good sign for domestic dog. I believe the person that took the photo had to see the animal make this sign to be able to take a photo of such fresh wet tracks and sign, as he must have been out walking with the dog while looking for wildlife tracks and sign.

That is exactly right. Three of us who were in Bemidji to take a Track & Sign Evaluation with David Moskowitz rented an Air BnB just outside of town. We were out for a walk the evening before the evaluation, exploring the neighborhood and looking for tracks and sign, accompanied by the property's resident yellow lab, Olaf. Shelly's interpretation of Olaf's behavior is uncanny, and a prefect description of what we saw that evening.

Incidentally, Olaf also had quite a nose for finding dead things. Earlier in the walk he brought us the rotting, partially degloved head of a woodchuck. We got some photos of that as well, but chose to use this sing for the natural mystery! Here is a photo of us with Olaf a just a little later in our walk.

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May 2019 Natural Mystery

posted May 13, 2019, 8:43 AM by Jonathan Poppele   [ updated May 13, 2019, 8:45 AM ]

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April 2019 Natural Mystery Answered

posted May 6, 2019, 1:46 PM by Jonathan Poppele   [ updated May 13, 2019, 8:59 AM ]

For our April Natural Mystery, I'd like to send out a special thanks and congratulations to Terry Hunefeld. Terry sent in the first correct identification of these tracks and offers us several helpful pointers in his answer. Terry is also our newest sponsor on Patreon, joining at the River Otter level. Thank you for your support of the newsletter and these Natural Mysteries, Terry! Congratulations also to Kirsten Welge and Rob Grunewald who also submitted correct answers this month. I'll let the three of them take it from here:

Terry offers us the following breakdown of the tracks:

Game bird track. Somewhat asymmetrical with partial webbing between toe 3 & toe 4. The feet are turned inward (pigeon-toed) unlike similar-sized quail tracks but characteristic of plovers. The bird is walking (thereby excluding birds that hop). Metatarsal pad registers lightly on the right track, not at all on the left. Track length 1.25"  Width 1 3/8"

Similar species eliminated:
Sandpipers and dunlin would register a hallux.
Piping and Semipalmated plovers are smaller.

Conclusion: Killdeer

And indeed, theses are Killdeer tracks. As Rob notes in his answer, few of us in Minnesota were tuned in to the nuances of shorebird tracks on our fist evaluation back in April of 2016, but we all learned a lot that day, and in the years since. Rob echos Terry's points in his own answer, noting:

Compared with sandpipers, killdeer tracks are more asymmetrical, trails are more pigeon toed, and tracks do not register toe 1, whereas sandpiper tracks reliably register toe 1.

Kirsten shares these points in her answer as well, while offering some additional refinements. Regarding the asymmetry of the tracks, she notes that "There is a greater angle between toe 2 to toe 3 (about 85 degrees), compared to toe 3 to toe 4 (about 45 degrees)." The roughly 45º and 90º angles Kirsten describes are fairly distinctive and can be used as a quick (though not foolproof) diagnostic for Killdeer. Kirsten also digs into the range maps and migration timelines to point out that the plovers and dunlin would be extremely rare to see in mid-April in Minnesota, whereas Killdeer are becoming a common sight.

Congratulations again to Terry, Rob & Kirsten. And thank you again, Terry, for your support on Patreon. Your custom ruler is in the works! And just so you know, I've been working on illustrations of Killdeer tracks recently. Here is a sneak preview of my draft pencil sketches. I'll have these done soon and will get them posted on Patreon where you and all the other supporters can download the images.

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Cedar Creek Wildlife Survey, Spring 2019

posted Apr 30, 2019, 12:53 PM by Jonathan Poppele   [ updated Apr 30, 2019, 12:53 PM ]

The 2019 Spring Cedar Creek Wildlife Survey took place on April 13, just after a late season snow storm passed through the area. Though the ground was covered with a few inches of wet, heavy snow, signs of spring abounded. Our teams reported budding trees, close sightings of warblers and other migrant songbirds, grouse drumming in the woods, and the courtship display flights of a pair of harriers. It was a beautiful spring day in the woods, made all the richer by the wonderful tracking conditions. Here are some highlights from the day.

Twenty trackers and naturalists gathered for the survey and divided divided into four teams to spread out across the snow covered reserve in search of tracks and sign of resident wildlife. One team headed up to the very north end of the property, to a roadless area of the reserve where we have never surveyed before. A second team walked the roads of the North Unit inside Gate 7 and two teams headed to the southeast corner of the property—one exploring the bison enclosure, and the other following the trails around Fish Lake.

Both teams on the north end of the property recorded a large number of fisher tracks and trails. This is the first time that we have recorded fisher in any of our spring surveys. But then, this is the first time we have had snow on the ground for our spring survey. To date, our teams have found fisher tracks on every survey when there has been snow on the ground, but have never spotted fisher tracks when the snow is absent. This late season snowfall gave us the chance to get a glimpse of spring time fisher behavior. Both teams found trails where fishers of different size appeared to be moving together on the landscape. Breeding pairs, perhaps? Mid-April is mating season for fisher.

The number of fisher trails the teams found piqued our curiosity once again about fisher range and population density. Are there just a few very active fisher on the reserve? Or are there fisher peering down at us from nearly every tree? A quick literature search1 turned up estimates of fisher density in suitable habitat range from one per 2.6 km2 to one per 10 km2. That would suggest somewhere between 2 and 9 fishers across the 23 km2 of Cedar Creek. Would it be possible for us to distinguish individuals based on track and trail measurements? If so, is it possible for us to get an accurate count of the number of fisher at Cedar Creek? Given estimates for home range size, most of the animals we see likely venture well beyond the bounds of the reserve. And given our dependence so far on snow for locating fisher tracks, such a project might need to wait until next winter--or require the use of baited track plates.

The team at the northern end of the property also found a high density of both deer and turkey sign, but no canine tracks. The team scouting the roads of the North Unit found two sets of fox tracks near the edge of the woods. In both cases, the animal was moving in a gallop. In past surveys, we have sometimes found large numbers of fox tracks on the road inside Gate 7, and at other times found few to none. Were the foxes avoiding the roads? Or did their day-to-day movements just have them elsewhere in the days leading up to the survey? One thing the team did not spot was any wolf tracks. This was the first time in any of our surveys that none of our teams found any wolf sign. A Cedar Creek staffer spotted fresh tracks in the North Unit the following Monday, so we know they are still around. But they hadn't passed along the routes we surveyed for at least a few days.

The team exploring the bison enclosure took advantage of the fresh snow to follow coyote trails across the landscape. One trail they followed ran nearly parallel to the sand road, about 50 feet off to the side—just far enough to avoid being seen from the road. Following in the coyote's footsteps, the team found the tacks and trails of pheasant, grouse, raccoon and fisher. A side-trip down the fisher trail led to a mostly-eaten gray squirrel, which had been investigated and perhaps scavenged by a raccoon.

Black Bear track
The area around Fish Lake offered the greatest diversity of tracks and sign on this survey. The team exploring around the lake found coyote tracks along nearly every part of their trail, mink tracks near the water's edge, beaver tracks and sign, and the tracks of several birds. Both this team and the team exploring the bison enclosure found turkey and sandhill crane tracks close together, and got some practice at distinguishing the rather similar tracks of these two large birds. The Fish Lake team also identified turkey tracks with wing drag marks left by a male in display, and the wing marks of a pheasant taking flight. The team also made the most surprising find of the day, picking up the trail of a black bear as it traveled along the edge of the bison enclosure. Bears frequent the northern half of the reserve, but sightings are quite rare on the south side of Fish Lake. It appears that this particular bear was likely foraging in the back yards across the road, because the scat our team found along the trial was filled with sunflower seed husks!

The juxtaposition of spring animal behavior and a snow covered landscape made for a wonderful day in the woods—and as usual brought about as many questions as it did answers. One big question on our minds is where are the wolves? It is not rare that we see only a little bit of sign, but this is the first time we haven't seen any. And apparently there were fresh tracks just a few days later. Have we just been lucky on our past surveys to cross paths with the wolves? The fresh snow limited what we could see to only sign from the past couple of days. Typically we get a longer window of track and sign ages to look for. But this raises the question, how much time do these wolves spend at Cedar Creek? And how wide to they range?

We are also curious about the fox activity. Some days our trackers have walked in from Gate 7 and seen multiple sets of fox tracks running up and down both sides of the road. On one survey a tracker joked that the foxes were running laps. Other days, there are no fox tracks to be seen along this stretch. What has the foxes sometimes use this road heavily and other times avoid it? Does this just reflect their movement about their territory? Or is something pushing or pulling them on the landscape?

Just how many fisher are there at Cedar Creek? Studies of fisher density suggest somewhere between 2 and 9. Can we narrow those numbers down a bit? Can we learn to identify individual fisher from their tracks?

Finally, what brought one of the bears down to the southeast corner of the property? Do the neighbors backyards offer good foraging for a hungry bear coming out of hibernation? And why didn't we see any bear sign on the North Unit?

We are looking forward to getting back out on the landscape to learn more about the wildlife at Cedar Creek. Please mark your calendars and plan to join us for our upcoming surveys.

Saturday, July 13
September 21-22

Powell, R. (1981). Martes pennanti. Mammalian Species, (156), 1–6.
Powell, R.A., Buskirk, S.W., & Zielinski, W.J. (2003). Fisher and Marten. In Feldhamer, G.A., Thompson, B.C., & Chapman, J.A. (Eds.). Wild mammals of North America: biology, management, and conservation (2nd ed). Baltimore, Md: Johns Hopkins University Press.

April 2019 Natural Mystery: Test Prep Edition

posted Apr 9, 2019, 7:41 AM by Jonathan Poppele   [ updated Apr 9, 2019, 10:08 AM ]

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March 2019 Natural Mystery Answered

posted Apr 8, 2019, 11:19 AM by Jonathan Poppele   [ updated Apr 18, 2019, 10:54 AM ]

Our March natural mystery was a tricky one, as small bird tracks usually are. In this case, it is possible to trim down the list of possible birds quite a bit based on when and where this photo was taken—in January in an urban area of St. Paul, MN. By making a list of possible birds, and comparing that to the size ranges in the literature, we are left with just a few candidates…

I'll start out by noting that this is an unverified track photo, so we may never be able to be 100% certain on the ID, but let's see how close we can get.

Kirsten Welge drew on her experience living in St. Paul to create a list of the most likely candidates: Northern Cardinal, American Robin, Black-Capped Chickadee, White-Breasted Nuthatch, American Crow, and Blue Jay. She measured the mystery track at 1 5/8” long, eliminated the corvids, robin and chickadee based on size, then selected the Northern Cardinal over the White-Breasted Nuthatch based on morphology. As she notes, “nuthatch shows a very skinny foot and a strong claw register – not a match for our mystery track.“

This is a good process, but there are a few other birds we need to consider before we conclude that these are cardinal tracks. Juncos, finches and even a few sparrows also frequent St. Paul in January. So let's take a further look at a more extensive list of candidates.

If we look on eBird for sightings in Ramsey County in January, we can put together a list of about 15 species of smaller passerines. Using size data from Elbroch & Marks Bird Tracks & Sign we can pare the list down even farther:

In our photo, the right track in each pair appears to be 1 1/2" long. Interestingly, the left track in each pair appears longer--about 1 11/16". Perhaps this is because of the way that foot drags the snow in the hopping gait, or perhaps the left foot is splaying more. In any case, we can use the range of 1 1/2” to 1 11/16” as a starting point.

Based on Elbroch's measurements, the tracks are too large to be a wren, goldfinch, house sparrow or chickadee. Though there are no data in the literature, comparing body to similar species we can likely eliminate American tree sparrow and pine siskin, both of which would also be unusual to see on a sidewalk in an urban area of St. Paul. The tracks are too small to be robin, starling, or blue jay.

That leaves house finch, purple finch, northern cardinal, dark-eyed junco, white-breasted nuthatch and white-throated sparrow as possibilities.

As Kirsten notes above, we can eliminate white-breasted nuthatch based on morphology.

While there is no published data for house finch or purple finch track sizes, we can make some guesses based on body size of these birds and comparing them to their slightly smaller cousin, the goldfinch. Assuming that these birds are proportional, we can compare various linear measurements such as body length, wingspan, and the cube root of body weight. I used data from the Cornell Lab's All About Birds website to do this, and found that house finch can be up to 10% larger than goldfinch and purple finch can be as much as 20% larger. This suggests that the tracks of these slightly larger finches would still be under 1 3/8”, making them too small for our mystery.

The tracks seem a little on the large side for any of our remaining candidates, but if we allow for the tracks appearing a bit large because of the snow, we can consider junco, white-throated sparrow and cardinal.

Dark-eyed junco tracks show slender toes and, of particular note, a slender hallux. These images appear to show plumper toe pads, particularly in the hallux, compared to junco. Elbroch also lists the hopping strides for juncos as 1-6”, while we were told that our trail showed hopping strides of 7-10”

White-throated sparrow also have a more slender hallux than cardinals, but the difference is less pronounced. Here again, Elbroch lists the hopping stride as 6” or less, where our bird was consistently hopping over 7”. We are also on the very edge of white-throated sparrow winter range, and they are a much less common sight in these urban areas compared to cardinals.

This leaves us with the cardinal as the last bird standing. The hopping stride fits Elbroch's data, the track size appears a tiny bit on the large side, but seems reasonable, and the morphology seems the best fit. Like finches, cardinals have a fatter hallux than sparrows and juncos do--particularly the proximal pad--a feature we see in these tracks. Although it isn't definitive, the clues we have available most strongly suggest that these are the tracks of a Northern Cardinal.

An Interesting Note: Elbroch lists the size of cardinal tracks as 1 1/4" - 1 9/16", which is still smaller than the measurement for the left side tracks--but he notes that his size range comes from a small data pool. If we the same calculations we used for the house finch and purple finch suggests a maximum track size for cardinals of at least 1 9/16" (the same as Elbroch's data pool), and possibly as much as 1 11/16" (the length I measure for the left track in this photo). But cardinals have a different enough body shape from goldfinch that I don't think this is more than a curiosity.

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March 2019 Natural Mystery

posted Mar 6, 2019, 12:01 PM by Jonathan Poppele   [ updated Mar 6, 2019, 12:03 PM ]

February 2019 Natural Mystery Answered

posted Mar 6, 2019, 10:32 AM by Jonathan Poppele   [ updated Mar 13, 2019, 11:05 AM ]

Our February Natural Mystery proved challenging--but two of you met the challenge. Congratulations to Anne Marie Meegan & Rob Grunewald for successfully identifying this common, yet surprisingly unfamiliar track. We are so used to seeing the full track pattern of this and related species, we may not recognize these two prints in isolation. Two prints--but not a double register.

These are, as Ann Marie put simply, "the front feet of a Lagomorph." Specifically, an Eastern Cottontail. Rob Grunewald identified the species and offered these additional comments:

"In a Cottontail's bound, the typical gait for this species, the front prints sometimes land next to each other, as pictured here. The animal is moving toward the top of the picture. You can see the entry at the bottom of the print where the snow is disturbed, the exit has a sharper edge."

The fur on the bottoms of rabbit feet tends to obscure the details of the foot morphology, but if you look closely, you can make out some toe pads, and even a couple of claw marks on the leading edge of the two tracks.

Thanks to everyone who tried their hand at this mystery--and congratulations again to Anne and Rob.

A Correction

Last month's Natural Mystery were the tracks of a flying squirrel. When I posted the mystery, I wrote that the photo came from Cedar Creek Ecosystem Science Reserve, in southern Minnesota. I was mistaken about this. The photo that I posted was actually taken in far Northern Minnesota, on the edge of the Boundary Waters Canoe Area. According to the range information I have been able to find, this means the tracks must be those of a Northern Flying Squirrel (Glaucomys sabrinus). The size of the tracks and the trail fit within the published ranges for both Northern and Southern Flying Squirrels, and the hopping gait is reported to be much more common for Southern Flying Squirrels. It appears, however, that it is not diagnostic. In truth, where size overlaps, I cannot find any features of the tracks or the trails that are diagnostic between these two species. Where their ranges overlap, it may only be possible to distinguish the tracks as Flying Squirrel.

My apologies for the mistake--and a delayed congratulations to Bren White, who was the only person (including me) to correctly identify this photo as the tracks of a Northern Flying Squirrel.

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