Welcome to episode 57 of the Mountain Nature and Culture Podcast, I’m your host, Ward Cameron and I’m recording this on April 1, 2018. This week I look at three amazing fossils that are teaching palaeontologists about the evolution of some of the world’s oldest creatures. I also look at the return of red fox to the Rocky Mountains. It’s an action-packed episode so with that said, let’s get to it.
Some wisdom from John Muir
I wanted to start today with a fabulous quote by John Muir. As a hiking guide and naturalist, I see too many people striding through the wilderness, eager to reach a destination, or bag a peak, yet they miss the beauty that’s all around them. For me, the best way to enjoy nature is to simply bathe in it. Spend time in the wilderness and let the energy and the ambience wash over you.
If you really want to experience the mountain west, then stop, sit down and listen. Wander slowly along trails while filling all of your senses with endless stimulation. Feel the bark of a tree; listen for the sounds that make up the unique chorus of each location; get down on your knees and look at the tiniest things you can find; and become a part of something far bigger than you.
John Muir was one of the greatest naturalists, nature writers, and activists that the U.S. has ever produced, along with the likes of Edward Abbey, Rachel Carson, Ralph Waldo Emmerson, Henry David Thoreau, and Aldo Leopold. He explored the American west during the mid to latter parts of the 19th century and was instrumental in helping to protect landscapes like Yosemite, Sequoia National Park, and the Sierra Nevada Mountains.
Muir first arrived in California in 1868 and soon after made a pilgrimage into the Yosemite Valley. Muir wrote that:
“He was overwhelmed by the landscape, scrambling down steep cliff faces to get a closer look at the waterfalls, whooping and howling at the vistas, jumping tirelessly from flower to flower”.
He was one of the first people to recognize the action of glaciers on the landscape and helped debunk the existing beliefs that the vistas were the result of earthquakes as opposed to glaciers.
Muir was instrumental in the creation of Yosemite National Park, first as a state park in 1890, and then as a national park in 1906.
In 1892, he helped found the Sierra Club and served as its first president. By the time he died in 1914, he had published some 300 articles and 12 books.
John Muir spent his entire life exploring, bathing in, documenting, and fighting to protect natural, intact ecosystems.
The John Muir Trail is one of the U.S.’s most beloved trails, yet had you asked what he thought of hiking, this was his response:
“I don’t like either the word or the thing. People ought to saunter in the mountains – not hike! Do you know the origin of that word ‘saunter?’ It’s a beautiful word. Away back in the Middle Ages people used to go on pilgrimages to the Holy Land, and when people in the villages through which they passed asked where they were going, they would reply, ‘A la sainte terre,’ ‘To the Holy Land.’ And so they became known as sainte-terre-ers or saunterers. Now these mountains are our Holy Land, and we ought to saunter through them reverently, not ‘hike’ through them.”
– John Muir
I couldn’t agree more.
Next up more Burgess wonders
New Burgess Shale Discoveries
The various exposures of the Burgess Shales in Yoho and Kootenay National Parks continue to provide new and exciting discoveries. It seems that each year introduces us to species never before described, or spectacular new fossils of old friends that allow palaeontologists to reclassify them based on new evidence revealed.
One such fossil is the newly described Habelia optata. This fossil is not new to palaeontology. In fact, Charles Walcott, the original discoverer of the Burgess Shales, described the first specimen in 1912, only three years after he first stumbled on this bonanza of ancient life.
A recent study published in BMC Evolutionary Biology has shed some amazing new light on this unique creature according to lead scientist Cédric Aria. In a recent CBC article, he stated:
“It’s like a centipede or perhaps an insect that would have not one pair of mandibles, but five.”
One of the challenges with fossils of the Burgess Shales is that they are found between two layers of shale. This leaves a flattened, reflective film in the rock layers. Think of them as a two-dimensional black and white photograph of an ancient creature.
This means that each fossil may represent an image of a different angle or aspect of the animal and thus reveal details not visible in earlier samples. It’s this constant evolution of understanding that helps fossils to eventually be classified in a much more exacting way.
At a minimum, palaeontologists need to see fossils samples that show the side, top, and front views in order to begin to get a better idea of the structure. As new fossils reveal new details, scientists get a deeper understanding of how the animal fits within classic scientific categories.
Charles Walcott knew that Habelia was an arthropod, but he didn’t have enough information to pin down where it fit within this huge group of animals. Arthropods are one of the most diverse classes of animals on the planet and include the insects, arachnids, crustaceans, and the group that contains millipedes and centipedes. Oh yeah, and my favourite, the trilobites. Essentially it contains all of the world’s invertebrates that have a segmented body, jointed limbs, and a hard shell. In total, they comprise some 80% of all animal species on the planet.
There are also two major groupings of arthropods: the mandibulates and the chelicerates, or more simply, the chewers and the suckers.
Mandibulates have, well mandibles, or chewing mouthparts, along with sensory antennae. They include the centipedes and millipedes, insects, crustaceans.
On the other hand, among the Chelicerates, we find animals that liquify their dinner before consuming it. Most familiar among this group would be the spiders, but it also includes ticks, scorpions, horseshoe crabs and sea spiders. While not all Chelicerates need to liquify their diet, most do.
Originally, Chelicerates were predominantly predatory, but over time have diversified to allow many feeding strategies, from parasitism (as in ticks), plant eaters, scavengers, and detritivores or animals that eat decaying material.
The one common thread is that they lack both mandibles for chewing and jaws, but they do still have a mouth. In addition, Chelicerates have six pairs of appendages, four of which are used for walking.
If you look at a Chelicerate such as a spider face-on, the chelicerae are the fangs which inject venom into their prey to paralyze them. Later, they inject digestive enzymes which liquify the interior of their chosen dinner and give them an organic slurpy.
Behind the chelicera are the pedipalps. This is the most variable appendage that Chelicerates have. In spiders, they’re small and form a sensory function. In scorpions, they’ve evolved into the large pincers used for capturing prey.
Finally, also attached to the head, or cephalothorax, are 4 pairs of legs.
Now back to the Habelia. This little guy has taken palaeontologists on a merry chase since the first fossil was discovered in 1912. It seems to have both antennae and mandibles, but more recently, it was also discovered to have chelicerae-like appendages.
OK, what exactly does this mean? The Burgess Shale contains fossils that are unlike any creatures on the planet today. The shales also represent an incredible feat of timing. At just over half a billion years old, they represent the biggest explosion of multicellular life that the planet has ever seen.
It was a time when aquatic creatures were experimenting with a multitude of basic anatomical adaptations and showing rapid evolutionary responses. During this time, animals were evolving hard shells for protection, and predators had to evolve responses to these hard shells. It seems like the Habelia, which scientists believe were chelicerates, evolved additional structures that are also found on mandibulates, including mandibles and antennae.
The Habelia, instead of the usual 6 pairs of appendages, had seven, and rather than adapting the appendages behind its chelicerae for walking, on the Habelia, they evolved into multiple rows of mandible-like pincers, each containing sharp teeth designed to crush the shells of small trilobites.
So, it used appendages that were supposed to be legs, as pincers. So what’s a Cambrian critter to do? It evolved five more pairs of appendages on its thorax that it used for walking. This was one unique animal.
It’s believed the pincers are used to help it to pierce the hard shells of trilobites, its main food. They would then feed the tiny pieces to the mouth.
As for the Habelia optata, it is now sitting alone on its own branch of arthropods, on a sub-branch of the chelicerates.
Now, how about another recent discovery, also from the Burgess Shales, but from a new outcrop in the area of Marble Canyon in Kootenay National Park. This study, like the previous one, was published by lead author Cédric Aria in the journal Nature.
This new site is offering palaeontologists a completely new look at old friends and new fossils previously unknown to science. This new species, Tokummia katalepsis might help us to understand how the mandibulates actually evolved. As already mentioned, mandibulates include modern-day insects and crustaceans, as well as the millipedes and centipedes. It is the most diverse group of animals on the planet.
Extremely high-quality fossils of Tokummia in the Kootenay exposures have given some of the earliest looks at the anatomy of mandibulates. The mandibles are used to grab, crush, and cut food.
While most of the Cambrian predators were quite small, a few like Tokummia and the formidable Anomalocaris were terrors of these early seas. While Anomalocaris could reach lengths of up to 2 metres, Tokummia was a more diminutive 10 cm, but still frightening hunter.
It could swim, but it was more comfortable on the ocean bottom using its legs to explore, much like a modern-day lobster. Also, like centipedes, Tokummia had a many-segmented body sporting legs for walking towards the front of the body, and more finlike appendages for swimming towards the rear. Atop its body was a strong bivalve shell protecting it from predators.
The claws emerging from the front of the shell, like those of lobsters, have one claw that’s fixed, and one that moves, allowing it to open and close. According to lead author Aria:
“The first image that came to me when I started looking at these appendages was that of an old can opener. In spite of their shape, these pincers were likely not robust enough to deal with the hardest shells or shields, such as those of trilobites. I rather see Tokummia feeding on smaller soft-bodied arthropods or on Oesia worms, which are abundant at Marble Canyon.”
For creatures like the Tokummia, the claws would be used to cut soft-bodied animals into tiny bite-size chunks. It may have fed regularly on the next creature I’ll speak about soon, a segmented worm called Kootenayscolex barbarensis.
While earlier in this story, I mentioned that the fossils of the Burgess Shales were flattened between layers and often looked like black and white photographs. What I didn’t mention is that most of them do still maintain a three-dimensional structure despite this flattening. In some cases, careful removal of some portions of the fossil can reveal hidden parts of the anatomy.
In the case of Tokummia, careful dissection of one of these fossils showed a pair of mandibles hidden beneath its shell. This is a huge discovery as it represents the earliest evidence of mandibles on Cambrian fossils. It also may indicate the genesis of the largest group of land animals on the planet – the mandibulates.
It was long believed that the Burgess fossils would reveal the earliest examples of mandibles. Several other potential fossils, in particular, those of Branchiocaris, Canadaspis and Odaraia, may likewise sport mandibles, yet the fossils so far discovered and dissected have yet to provide clear evidence.
Tokummia has now paved the way for new areas of study as thousands of specimens languish in museum drawers and new ones are discovered. The unparalleled wealth of fossils that have been collected in the various exposures of the Burgess Shales, along with rapid increases in the ways scientists can peel away layers to reveal internal structures, will likely lead to many more discoveries.
So far this week, I’ve looked at an ancestor of modern-day scorpions, spiders and horseshoe crabs. Then I looked at one of the earliest creatures to display mandibles. Both of these animals were fearsome hunters patrolling the Cambrian seas.
The first, Habelia hunted hard-shelled animals like Trilobites, but Tokummia, with its delicate pincers, would have patrolled the ocean bottom looking for softer morsels. What kind of foods would it feed on?
Once again, the new Burgess deposits at Marble Canyon in Kootenay National Park may have provided the answer; bristle worms. Bristle worms are incredibly common in the oceans today. With over 10,000 known species, they are one of the most common of undersea creatures. Essentially, they’re a segmented worm, or annelid, with each segment sporting numerous bristly projections called chaetae which are made of chitin.
Today, bristle worms are incredibly easy for biologists to study simply because they are so plentiful. However, if you turn the clock back far enough, there is little evidence of soft-bodied creatures like worms in the fossil record. Fossilization in and of itself is a very rare process. Most organic matter decomposes long before it ever has time to fossilize.
When something is lucky enough to leave a fossil record, it’s usually just a record of the hard parts, like impressions of the shell, or the bones of dinosaurs. In very, very, very rare cases, such as in the Burgess Shales, the process allows the remains of animals with no hard parts to be perfectly recorded in the fossil record.
Danielle Dufault Royal Ontario Museum
This is the magic of the Burgess Shales, and in the new Marble Canyon site, a newly discovered bristle worm called Kootenayscolex barbarensis, is helping palaeontologists rewrite the evolution of the heads of worms. Never before have so many fossils of bristle worms been recorded in such a pristine character. As Dr Jean-Bernard Caron, Senior Curator of Invertebrate Palaeontology at the ROM stated:
“While isolated pieces of annelid jaws and some annelid tubes are well known in the fossil record, preservation of their soft tissues is exceedingly rare. You need to look to truly exceptional fossil deposits like those found in the 508-million-year-old Burgess Shale locality in British Columbia to find well-preserved body fossils. Even then, they’re quite uncommon and many of the currently described species there are still poorly understood.”
Over 500 examples of this one species have already been excavated from the rock layers and it’s given scientists like Karma Naglu, a researcher with the Royal Ontario Museum, a new look at a very old creature.
In modern bristle worms, the bristles do not protrude from the head of the worm, instead, they are limited to all of the other segments. However, this is not the case in this worm. As Naglu stated in an article published by the ROM:
“However, unlike any living forms, these bristles were also partially covering the head, more specifically surrounding the mouth. This new fossil species seems to suggest that the annelid head evolved from posterior body segments which had pair bundles of bristles, a hypothesis supported by the developmental biology of many modern annelid species.”
Essentially the head evolved from a normal section of the body, complete with bristles. In addition to the bristles on its head, it sported two sensory structures called palps and a smaller antenna between them.
The Cambrian explosion saw the first emergence of many of our modern biological lineages, but many of the creatures are markedly different from their modern ancestors. Each year palaeontologists working on Burgess Shales fossils continue to peel back the layers of time, and in many cases, the layers of shale, to uncover new creatures, new discoveries, and a growing understanding of how life evolved on this planet. I can’t wait to see what they discover next.
Up next red fox return to the mountain parks
The Return of the Red Fox
The red fox is not just beautiful, but it’s the most widespread carnivore species on the planet. It can be encountered anywhere in the northern hemisphere from the Arctic Circle all the way to northern Africa.
They are clever, adaptable, and do just fine in close proximity to people. They are common across most of Canada, but until recently, they have been exceedingly rare in the mountain parks.
Anybody that owns a dog knows dogs are funny animals. They get along with some dogs and not with others. This is also true when we talk about the various wild dogs that wander the forests of North America. Wolves, coyotes, and fox have very different relationships with one another.
Biologists use the term trophic cascade when referring to indirect relationships between predators or prey in an ecosystem that reverberates down through the community.
Every change people make to ecological communities cascades down the food chain and impacts many different plant and animal species. Over the years, we’ve seen many trophic cascades in the mountain parks. Predator control through much of the 20th century allowed elk to reproduce unchecked and have huge impacts on the landscape.
There has been a tonne of research talking about how removing carnivores from the landscape allows prey animals to explode. Hunters have taken advantage of this throughout much of the past century. Fewer wolves and cougars mean more elk, moose, and deer to shoot.
Elk are voracious predators in their own right, but they focus on aspen and willow. Without wolves to limit their numbers, they in turn, limited the number of aspen and willow trees, amongst other plants in their range.
One area of research that has been missing is how removing wolves from the ecosystem affected other carnivores, in particular canids like coyote and fox.
I moved to the Bow Valley more than 30 years ago, and I’ve seen an amazing amount of change through the years. I was here in 1987 when the biggest wolf study in North America, the Central Rockies Wolf Project, was initiated.
By the late ’80’s wolves had begun to return to the Rockies and to be a retain their role as the top-level predator in the mountain parks. This study opened the eyes of biologists as they began GPS collaring wolves and saw the extent of their wanderings. One wolf, nicknamed Pluie, travelled from Banff, south to Montana and Idaho, through parts of British Columbia, and back to Banff. In her lifetime she made 3 trips to Montana.
For the first time, biologists began to, not only understand the vast ranges that wolves travelled but also how important it was to keep equally vast areas of protected habitat. We began to realize that even the four mountain parks of Banff-Jasper-Yoho-Kootenay were small compared to the vast areas that wolves regularly move.
It helped inform wildlife management for the decades that followed. Pluie taught us more about how wolves use the landscape than any wolf before or since.
But let’s get back to red fox. For decades fox were a rarity in the mountain parks. I’m sure they were here, but their numbers were very low. As a guide, I’m out on the roads or trails almost every day during the summer season. I’m also part of a community of other guides that are also plying the roads and trails of the mountain corridors.
From the time I first arrived in the Rockies as a seasonal park naturalist in 1983 until sometime in the mid-2000’s, I never encountered a single fox in the mountain parks.
I can’t remember the exact year, I’m guessing it was around 2005 when I was guiding a local tour around the Banff area. We were just pulling out of the Lake Minnewanka parking area when one of the guests called out that there was a fox in the parking lot.
Being the unflappable expert I like to think I am, I began to pivot my body towards the sighting while initiating my verbal correction that it would not be a fox but in actual fact, a coyote. As my eyes focused on what I assumed would be a coyote, I realized that in fact, it really was a fox.
This was my first fox sighting since my arrival in the mountains. To say that I was excited would be an understatement. Growing up in Thunder Bay, Ontario, I was used to seeing these beautiful, yet diminutive carnivores on a regular basis.
As a wildlife photographer, the first image I ever had published, when I was about 20 years old, was of a red fox, just as I was beginning my career as a naturalist. I’ve had a long relationship with fox and I was, as the Brits say, gobsmacked to see one in my adopted backyard.
Recently, Banff Park Wardens have begun to see more and more fox on their wildlife cameras throughout the park. Of the 200 cameras in the park focused on long-term monitoring of wildlife, fox have been seen on around 20% of the camera’s and recorded some 1,400 times.
They are generally found on the Alberta side of the divide so far, but they’re also moving uphill to sites like Egypt Lake. Their population is on the upswing and if you’re lucky, maybe you’ll get a chance to see one in your travels through the mountains.
What’s the point of this story? The point is simply that wolves, coyotes, and fox are intimately connected. To most of us, they may simply be various kinds of dogs hunting through the mountains, but there are distinctive relationships between the three species.
For several decades, in the absence of wolves, the dominant canine predator in the Rockies was the coyote. After a generation of wolf suppression, coyotes emerged as the top dog in the mountain parks.
Wolves, coyotes, and fox have co-evolved for millennia, each competing with the other for their piece of the prey-pie. Until recently, few biologists looked into the relationship between these three canids.
When wolves from Jasper National Park were reintroduced to Yellowstone National Park in 1995, it was the first, large-scale predator reintroduction in a generation. Canadian wolves were parachuted into a landscape that had not seen wolves since the 1920s.
In the absence of wolves, coyotes had become the primary canine predator in the park, and over time, coyotes displaced fox in the park.
Studies in Yellowstone showed that coyotes suppressed the populations of red fox. While coyotes rarely took down adult elk, they were quick to take advantage of winter-killed animals. At these kills, fox were either displaced or deterred in 47% of observed encounters between February of 1991 and April of 1993. In some occasions, the coyotes killed the fox. In the end, fox populations dropped as coyote populations swelled.
While no studies that I’m aware of have duplicated these results in Canada, it seems plausible that as coyote populations grow, fox populations drop.
In a 2012 study published in the journal of the Ecological Society of America, biologists tried to define the three-way relationship between wolves, coyotes, and fox in North America.
The study realized that, for most of the 20th century, we have not seen predator-prey relationships as they would have been prior to the arrival of people to the west. We didn’t arrive and observe, we arrived and interfered.
We’re now seeing a trophic cascade that descends from wolf to coyote to fox. In a landscape that includes all of three canine carnivores, there are very specific interactions, as well as implications for both the population and the prey.
Wolves are the top dog in terms of canine predators. This is their turf and they have a very specific routine. They work in extended family groups taking down the very largest of the areas herbivores. They don’t waste time with snowshoe hares or smaller prey but focus on elk, moose, and the occasional bison.
Along their side were the coyotes. Coyotes are flexible in their behaviour. They are, without a doubt, the most successful of all three of the canine hunters. As wolves were being wiped out from much of their historic range, coyotes actually extended their range, despite the same efforts focused in their direction.
Coyotes though aren’t going to take down a bison. They’re not going to tackle an adult elk or a moose. They hunt medium-sized prey like snowshoe hares, but also suppress smaller predators like the red fox and house cat.
In towns like Canmore, you can’t walk down to the local community garbage bin without seeing a “have you seen fluffy” poster. If you let your cat out at night then it’s just part of the food chain. To a coyote, there is nothing like a filet of Fluffy on a dark night. Like a fox, house cats are a competitor to coyotes.
Coyotes love a good rotting carcass, and wolves are very good at generating them. Unfortunately for the coyotes, wolves don’t always want to share their spoils.
At the same time, it’s also well documented that coyotes displace, deter, and kill red fox in their territory.
Biologists refer to this as a top-down cascade. Wolves deter coyotes which in turn deter fox. Now here’s the twist. Without wolves, coyotes rule and fox are the losers. This may explain the relative absence of our rust coloured friends for decades.
Bring back the wolves, and coyote numbers drop, reducing the pressure on fox from coyotes.
It’s essentially a three-sided triangle where one canine predator deters or kills the next. While coyotes compete directly with wolves as scavengers of their kills, fox have very little overlap in feeding behaviour with wolves. They do, however, compete directly with coyotes.
How does this wolf, coyote, fox interaction affect the other components of the ecosystem? Well each of them focuses on different types of prey. Wolves take down large hoofed animals, coyotes hunt medium-sized prey like snowshoe hares and red squirrels, and red fox take down even smaller prey like mice and voles.
On an ecosystem level, high wolf population will mean less hoofed animals, and with increased numbers of fox, fewer small rodents.
Who cares? Well as scientists try to predict ecosystems, they also need to look at the whole picture. Let’s look at just one current news item; Lyme disease. The ticks that transmit Lyme disease needs two hosts; an adult deer or elk as a reproductive host, and small mammals like mice or voles as earlier stage hosts in order to keep spreading.
In a landscape that includes both wolves and red fox, the wolves help control the elk and deer while fox help to keep the smaller rodents in check. By controlling both ends of the host spectrum for Lyme infected ticks, wolves and fox can play an important role in reducing the spread of Lyme disease.
In a coyote dominated landscape, they feed more on intermediate-sized prey like snowshoe hares and squirrels, neither of which play a role in the spread of Lyme disease. It may just turn out that wolves and fox may become a critical tool in the fight against Lyme disease.
In Yellowstone, the reintroduction of wolves had a profound impact on the landscape. Everything changed as they began the work of rebalancing the ecosystem. Elk numbers dropped dramatically, which allowed the willows and aspen to begin recolonizing the landscape.
Rivers which had been heavily eroded from over browsing began to stabilize their banks as new growth helped to hold the soils together.
Coyote numbers dropped which allowed squirrels, snowshoe hares, and red fox back onto the landscape.
This is the perfect example of a trophic cascade. The reintroduction of the wolf had impacts that rippled through the entire ecosystem.
Be sure to check out the video below. It showcases the amazing changes that wolves brought to Yellowstone National Park.
This summer, the bison in Banff will be released to wander a much larger area and will, for the first time, be part of Banff’s food chain. It will be interesting to see how the wolves and other predators react to this new arrival. I spoke about how wolves have adapted to bison in Yellowstone in episode 30, I spoke about some of the new research into wolves and bison and how they currently interact. You can listen to it at www.MountainNaturePodcast.com/ep030.
And with that said, it’s time to wrap this episode up. Remember that Ward Cameron Enterprises is your source for step-on, hiking, snowshoe, and photography guides in the mountain parks. Check us out at www.WardCameron.com. If you’d like to contact me directly, you can hit me up on Twitter @wardcameron, or visit our facebook page at www.Facebook.com/WardCameronEnterprises, and with that said, the sun’s out (finally) and it’s time to go snowshoeing. Happy Easter and I’ll talk to you next week.