Studying Pressure releases in the tracking sandbox – July 6th and 7th, 2019

Studying Pressure Releases can be very difficult, especially if you are doing it on your own, or perhaps having only one or two resources to work from, so it made for a lovely weekend up at Earth Tracks headquarters to study Pressure Releases with a motivated, curious and fun group of folks, despite the heat and humidity.

Pressure Releases (“PR” from here on) are sign written within or without the track of an animal created by pressure against the substrate the animal has moved over. This could be some dirt thrown up by a boot coming down on a muddy path, or a tiny sand ridge created by the pressure of a frogs hind leg as the frog lands in a sandbox (more on this example later…).  They are created in the substrate by a bodies weight, by the shifting of that weight, and through the motion generating pressures and then how the substrate reacts to those specific pressures.

Tom Brown Jr's book "The Science and Art of Tracking"

Tom Brown Jr’s book “The Science and Art of Tracking”

There are many examples of PR, all of which we learned about this past weekend can be found in Tom Brown Jr.’s book “The Science and Art of Tracking”. We really studied three causal qualities of PRs actually

  • 1) Pressure Against The Wall, which can teach us about turn a body in motion has made, sudden stops and even the eventual position of the next track by observing the increasing intensity of pressure required to create different possible PRs in the previous track. With names like “ridge”, “crest”, and “cave”, these PRs are like microcosms of the greater landscape though they are sign written by a foot (or other part of a body in motion) putting pressure on the substrate.
  • 2) Changing Or Maintaining Forward Motion, which teaches us about how much energy was required to, you guessed it, change or maintain forward motion. This might include speeding up from a slow jog to a fast jog, to a fast run for a human, or in the coyote counterpart, trot, bound, and gallop, all the while only looking at one track instead of requiring a set of tracks to determine a gait pattern.
  • 3) Roll and Head Position, which could mean looking at the depth of toes or the heels to determine if the animal, human or not, was looking up or down.

Tom Brown covers many more PRs with seemingly endless variability for each depending on a wide variety of influences and outcomes. I would be helpful to find his book and study it while working in a tracking sandbox.

Alexis explained the PRs, using diagrams written on a flip chart to help elaborate, and then demonstrated by moving through the tracking sandbox. He asked us to imagine an hour hand of a clock protruding from his chest and facing 12:00 and then he turned his torso very slightly so he would be facing 12:15 on the clock, and then 12:30, and then 1:00, with each turn taking a new step to create a new set of tracks. Each track would show slight variations in the pressure in the wall of the track highlighting the turns Alexis was making. These could be read by turning our heads so we could see the horizon of the sand and noting the peaks in the displaced sand which now stood atop the wall of the track, or by the way a toe seemed to dig into the floor of the track creating a small indentation or “cave” where the floor of the track met the wall.
This is just one small example of a PR.

The day went on, and we all took turns stepping into the sandbox moving in small ways, or big ways and then after stepping out of our tracks examining the PRs which remained.


Disk – light intensity


Disk-fissure – more intensity


Dish-crumble – even more intensity


We took a break on our first day to drive a little ways to a nearby woodland, but then got back in the sand the next morning. We began with the 3rd study, Roll and Head Position, where Alexis stood in the box and demonstrated head turns and the resulting PRs.

Examining the PR created in the track by looking over the Left Shoulder. Note the longer shadowed area on the left side of the left track denoting the greater depth to which the left foot sank due to the shift in weight.

A highlight of the morning was being visited by a Northern Leopard Frog (Lithobates pipiens) which was quickly placed in the tracking box so we could observe their movements and the PRs left behind as they hopped out and made their way back to the pond.

Lithobates pipiens

Note increased depth in the print of the hind leg on left side denoting more pressure from this foot created by pushing out of the sitting position while hopping out of the sand.










Later still, we tried another activity in the box. While everyone else was looking away, a student moved through the box with variying speed and actions while being filmed. When the student was done and camera stopped, everyone returned to the box to try and decipher what had just taken place. We used our bourgening knowledge to explore the PRs and movements highlighted in the tracks to figure out what had just happened, and after a few minutes of discussion and comparing ideas, we reviewed the video to confirm or challenge what we thought had happened. What excitement it was to be right! What joy to be wrong! It was so much fun to see where there was a forward bend with head facing the left, when we thought the head was straight and the fissures and crumbles were created by increased speed. This activity was certainly a hit.

First, try and decipher the tracks… then watch the video.

Studying PRs is a lifelong commitment. Perhaps many lifetimes of work is required to truly master and understand all the possible interpretations which lie in a track.

I am in deep gratitude to Tom Brown Jr, Alexis Burnett, and all the other teachers who take the time to pass on these skills to others so that we can hopefully build on this great moving body of knowledge even more, and explore, decipher and celebrate the mysteries we encounter, in the sandbox or the woods.



Story of the day – Krug Tract in the drizzle

Our cool (but not chilly) breezy day began with gifts and gratitude. Upon our arrival at the Kinghurst Forest Nature Reserve we were blessed with a sighting of a great blue heron. As people were packing up their belongings, those listening closely may have heard a shallow peeping noise coming from the ditch. Before we could look twice, a spooked baby fawn darted across the road and back into the forest. We immediately went into tracking mode and delayed our usual gratitude circle to get lost in the moment.  We noticed some blood in some of the hoof prints.

Here is Alistair measuring between tracks with his walking stick. He has marked out a ruler along the side and bottom. This way he can better interpret the gait patterns and this tool helps him find the next track. As he finds the tracks he can then mark them at the back of each with a popcicle stick. This way he can look down the trail and see better the repeating pattern of the fawns footfall.

measuring with walking stick

measuring with walking stick

We followed the fawn’s trail all the way down the road. making out faint tracks in hard packed gravel.

After tracking the fawn for a while we got back to opening circle.

Our field guides help us dive deep into the mystery of the questions that arise through careful observation.

Alexis examining a blue egg. Could be a Robin egg, but there are other birds who lay similar sized blue eggs.

Stephanie takes a souvenir home to examine more closely.


As we passed through the forest, we found blue bird egg shells, and wondered if they were from a robin or from some other kind of bird that also has a blue shell. Someone noticed that the shape of the shell seemed to be more oval than that of a typical robin egg.

Kaya’s bug protection is ON POINT.

We examind some long dark feathers that have possibly been sitting in the same location for multiple years. Like an old kill site, definitely a feeding site. The feathers had been chewed off, not clipped.

Porcupine kill site?

looking at beaver chews

looking at beaver chews










Throughout the day it drizzled a bit but we got to see fresh tracks in the soft ground and the smells were just so full. Grateful for another day on the land.

jewelled leaf

jewelled leaf



Along the shores of Lake Huron in Saugeen FN

We got out of the cars and stretched a little, letting the blood recirculate to all the places it struggled to reach on the drive out there. We laughed a little dizzy from standing up too fast and handed out the books and grabbed our bags.

In less than a minute we all had our eyes to the lovely Yellow Lady’s Slipper growing alongside the trail in. A few short seconds later, Scarlet Painted-Cup (Castilleja coccinea) and Sundew (Drosera rotundifolia) dotted the moist grassy knolls between the sand and the water of Lake Huron.

Castilleja coccinea

Castilleja coccinea

Drosera rotundifolia

Drosera rotundifolia








This was a sandy beach country, with small patches of Cedar, rushes, and grass anchoring some of the taller mounds of sand preventing their erosion back into the lake. This is where the lovely Scarlet Painted-Cup (Castilleja coccinea), otherwise known as Indian Paintbrush or just Scarlet Cup, and the Sundew helps us to understand this landscape and perhaps start making some connections with who else may be out here. I am always trying to remember that these plants we meet can teach us about the land as much as the animals we track.

We moved on just a little further to study the trail of a yearling White Tailed Deer (Odocoileus virginianus) walking alongside their mum, a track we picked up on a couple of times. We also noticed  the trail of a younger fawn further North along the beach. The track of this young fawn was only about 2.7cm wide! It is sometimes hard to imagine an animal who can run so fast and will grow so big with such small feet… and some don’t make it at all.

We later found a young fawn’s unguis, perhaps analogous to our fingernails, which make up the walls of the hoof, in some nearby scat.

The unguis is composed of compressed hairs glued together by the proteins in the deer’s body. It adds to the strength and rigidity of the hooves and this durability is likely why the unguis made it through the coyote’s digestive track mostly unscathed. It still smelled like it had made it’s way through the coyote’s digestive track.



small deer track with measurement

small deer track with measurement

Shortly before lunch I heard a call from up the waters edge. Someone had found something special. I made my way carefully past more sundews and other lovely beach plants and came around some short cedar’s when Alexis asked “Does anyone want to make a guess…” and I stood there for a moment, stunned and then thought I knew. “Just call it out if you think you know” Alexis instructed.

“Snapping Turtle!” I called out, but immediately thought differently as others pointed out the obvious. This skull was too big to be a Snapping Turtle.. And if a turtle at all, likely some sort of Sea Turtle, but that just wouldn’t belong here.

I heard others mention fish quietly, and I realized who it was for real this time.

“Carp?” It was a Common Carp (Cyprinus carpio), and what a mighty big skull this fish had.

Non-native to the Great Lakes, but spread widely throughout, this large fish may have been visiting this flooded beach to mate, and lay eggs, or perhaps just washed ashore dead and eaten by some carrion eater. We found scales in the grass and in the water beside.

Common Carp (Cyprinus carpio)

Common Carp (Cyprinus carpio)

Common Carp (Cyprinus carpio)

Common Carp (Cyprinus carpio)








We took some time for lunch, and continued on admiring strange hare tracks with an uncertain course, a turtle trail cut through the silt of an ephemeral pond in the middle of some four wheeler tracks, a person whose tracks told they may walk with a limp on the left side, and a Black Bear, crawling up the sand bank and heading into a thicket of Eastern White Cedar. All quite engaging, full of mystery and wonder. This is why tracking takes hold of us, inspiring awe at the mundane: being able to see into time when weren’t present and noticing the ways life and death moves across the landscape (and lakescape).

One of the most impressive mysteries came near the end of our day together. Annie and Steph had spotted some old scat on a trail to the west of the one most of our crew was exploring. I walked past them and heard the excitement in their voices grow louder, higher in pitch and faster in cadence. Finally I had to turn back and see what they had found.

“..and a hand! And look at those teeth!”

I was glued to the scene before I even saw what they were looking at.

“A Shrew!” they announced as I walked up and sat down beside them. I saw the lump of grey patchy fur and small boney hands. I scanned the form in front of us and saw the rusty red teeth they had excitedly been yell-talking about moments before. I agreed that I also thought it was a shrew, but then offered a question, why was it here, dead and dishevelled looking?

We threw out some answers – perhaps someone had stepped on them [singular them]? Perhaps they just had died? Was it an owl who ate part and spit out the rest? A couple more hypotheses were thrown in, and I offered what I had learned last year from reading the Short Tailed Shrew (Blarina brevicauda) entry from Donna Naughton’s book “The Natural History of Canadian Mammals”.

Short Tailed Shrews taste terrible to most animals. Great Horned Owls, who have great hearing and sight, lack in the smell and taste department. They eat shrews readily, but most mammals find them gross.

I shared that I had seen quite a few dead shrews, many with bites out of their sides, but mostly intact and left behind in the woods likely where they had been killed. I then proposed my theory that this chewed up shrew was caught and killed by a larger mammal predator, perhaps fox or coyote, and then when they tasted the shrew thought differently of eating them, and instead spit them out. This would make sense for the mangled look of the body, and for the fur missing.

It was decided that this was plausible and we replaced “Grim Shrew” (as we had been referring to them) back where they were found and made our way to meet up with the rest of the group before we walked back to the parking lot for the tired drives home.

It was a good day.

"grim shrew"

“grim shrew”

shrew head and hand

shrew head and hand











Story of the Day for May 11 2019, Orangeville Pits

Overcast and windy for most of the day until around 2:45ish when a light rain began. 8-10°C

Waxing Crescent 44%


We began the day with an opening circle on the sidewalk across the road from some newly constructed and in the midst of constructed houses, edging on to an old sandy quarry and mixed Cedar forest. It seems sometimes like this might be the wrong place to be tracking, but life exists everywhere so off we went, and almost as soon as we stepped into the construction site we discovered some tracks.

First thing we noticed was that the claws were pretty far out in front from the toes and there appeared to be 5 toes in the tracks, at least the clear ones. Some of the tracks showed a faint rear track in front of a front track, and the stride measured in at around 16.5 cm (6 ½ in). Some thoughts were quickly thrown around and then finally we settled on Mephitis mephitis moving at an overstep walk. Can you see the hind foot landing in front of the front foot in the photo?

Nearby we also noticed a couple of potential Vulpes vulpes tracks. There was a thought to peel the top layer of mud off but it seemed like the track wouldn’t lift so it was left to it’s own to fade to time.


We took a sandy path further away from the newly built homes, passing Sylvilagus floridanus chews and Canis latrans twisted hair-filled scats and came across a hole, a deep hole, a 35.5 cm (14 in) deep hole nearly straight down into the sand right in the middle of a heavily used path. Who could it be? There were measurements and estimates, more measurements and guestimates, but no conclusions from the group, even after we saw a small track – 7.62 cm (3” in) x 6.35 cm (2.5” in ) – just off to the right of the hole. Tamias striatus, or Tamiasciurus hudsonicus..  We just couldn’t tell. Can you? 


Pellets seemed to be falling from the sky today. We may have found 5 today. Big ones, little ones. Skulls, jaws, mammalian bones, bird bones, all over the Pits.


Next we moved on to look at some Odocoileus virginianus tracks, and we talked about the dew claws and how on one set, the fronts or the rears, the dew claws are closer to the two hooves in front of them. We also noted that the dew claws which were closer to the hooves were used for traction, to help the animal “steer” better. These closer dew claws also tended to be fatter yet not as splayed out or wider set than the others… Do you remember which dew claws are closer to the hooves used more often to help “steer” this animal as they move?

As we moved through the sand we noted many more animals making their ways through. More Canis latrans, more Odocoileus virginianus, but we took some time to examine the Meleagris gallopavo tracks, and especially the remaining sign. We examined the scat left behind, and how the scat will be in different forms depending on the sex; there will be longer and tubular, perhaps even slightly “J” shaped for one sex, while the other’s scat will be globular, rounded and clumpy. Whose is clumpy? Whose is tubular?

It was fun to notice how when they nip the grass they are leaving a pretty straight, flat, even cut across the top, which eventually dries, withers slightly and changes colour, from green to a pale yellowy white. Lagomorphs and rodents will bite the grass off at a 45° angle, deer will be a little ragged, and dogs and cats even more so.


We continued on, looking at gaits of domestic dog and remembering that this is a practice, a skill which will take a lifetime of practice and study. We will learn to see the tracks and the gaits the animals are using. We will learn to know these gaits by heart, and perhaps even imagine seeing the animals in our minds moving across the land as look at these tracks left behind. The science may developing into a profound intellectual knowing which may help us to develop our instinct and our gut knowing, and someday, with lots of study and practice begin to sense from seeing how the tracks land across the substrate, a deeper connection with these animals we are tracking. I look forward to a time when I know and understand the science in a deep enough way, that I can read the signs with a little more instinct and a little less intellect.


Afterwards we broke out on our own for a discovering a bird kill site, a larger rodentish skull, and some old honeycomb at the base of a Tsuga canadensis full of holes. Then, after regrouping and slowly making our way through sheltered forest of Thuja occidentalis, Populus tremuloides, Prunus serotina, and Betula alleghaniensis, we found another pile of bones! This time a bird.

We examined the carpometacarpus, the ilium, the femurs and the skull! We tried to look up the skull in Mark Elbroch and Eleanor Marks book “Bird Tracks and Sign” but we couldn’t decide in the end who this bird was. We had some approximations, but no certainties.. Do you know whose skull this is?


We closed out the day with a closing circle, sheltered from the wind and rain sharing our gratitude for the animals, for the forest beside the subdivision, for the skulls we found, for the comradery of our crew, for the sand pits full of tracks, and for the chance to reconnect with land. All left looking forward to next month.

Written By:  Byron Murray – 2nd year Tracking Apprentice


Twas December 2nd

Twas December 2nd

Written by Tamara Anderson


‘Twas December 2nd, when all through the house

Plant apprentices made medicines, some with calendula flowers.

The salves were made on the stove top with care,

In hopes that there would be plenty to share;


We learned about the folk method for making tinctures

And the standardized calculation for herbalist thinkers.

With guidance from Alexis, so lively and quick,

“Almost there!”, the cough drop liquid was becoming thick.







When out in the kitchen there arose such a chatter,

Fire Cider was being made with plant-based batter;

Turmeric, cloves, ginger, garlic, white pine and horseradish;

Onion, jalapeño, cayenne pepper, rosemary and lemon zest.

What to our wondering eyes should appear on the counter;

But many tiny jars of salves, syrups, and balms to prepare for winter.

The secret planta gifts were gathered on the table,

The gifts were plant-based, like syrup from maples;

Or small zines about winter weeds made from paper.


And then, in a twinkling, the weekend was done.

Hugs and well wishes to all for making it fun.

Hearts filled with love and gratitude

For the many plants that we used;

And for the people who harvested and prepared them;

May our paths cross again!

Herbal cough drop recipe:


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