So, four years ago, as a volunteer at the University of Montana Zoological Museum, we
got a call from Montana Fish, Wildlife and Parks about a gray wolf that had been hit
by a car -- and, as many of you still fondly remember, we filmed aspects of the preparation
process: skinning it, and gutting it...
You know, all the pretty parts.
This was because I really wanted to show you guys how museums turn road-killed
animals into valuable research specimens.
That was also the series where I also accidentally misdialed Lenscrafters - which maybe became
one of the funniest things to ever happen in the history of The Brain Scoop.
Those videos gave us a chance to talk about anatomy and physiology- so while I dove into
its stomach contents to figure out what it was eating, we didn’t really get into any
questions that that specimen could help us answer.
I also didn’t even talk about the incredibly complicated history of wolves and people,
or the important role wolves play as top predators in their ecosystems.
It’s nearly impossible to know where to begin with this subject: wolves are some of
the most highly studied animals on our planet, and the relationship between wolves and people
itself is prehistoric.
There’s an overwhelming amount of information out there, to the point I nearly scooped my
own brain out just trying to research for this episode.
One of the most confusing things is trying to figure out just how many different kinds
of wolves are in North America today, and how distinct each of those kinds really are.
So for the sake of needing a starting point for this video we’re recognizing gray
wolves, eastern wolves, and red wolves as distinct types in the U.S.- and Mexican wolves,
Arctic wolves, and great plains wolves as populations, or subspecies, of those three.
The conflict between wolves and people has been called “the longest, most relentless,
and most ruthless persecution one species has waged against another.”
In the 2003 book Wolves, the authors put it this way:
“To many humans, this animal is the ultimate symbol of wilderness and environmental completeness.
To others - for example, a Wyoming rancher or an Italian shepherd - it represents nature
out of control, a world in which the rights and needs of rural people are subjugated by
city-dwelling animal lovers intent on imposing their conservation values on others.”
...and they’re not wrong.
The animals in this episode are small parts of a huge, complicated story we’re going
to tell about American human and scientific history, and ethics - endangered species,
and philosophy - and what the future looks like when we try to fit the messiness of nature
into neat, legal boxes.
And when I mean messy, I mean… we got kinda messy with this one.
Let’s go.
Before Europeans began settling across the United States - before they were
even called the United States - this was a country of diverse, Native peoples and abundant
wildlife - including wolves.
Wolves were spread across North America, with an estimated population of around 380,000
individuals.
But pretty much as soon as the ‘Pilgrim Fathers’ arrived in the early 1600s, so
did their efforts to eradicate wolves - as they had just exterminated the wolves in England
and across Europe.
Human-wolf conflict is an ancient story: depending on which cultures and periods you’re looking
to, people either saw wolves as totems and positive symbols of strength (like in many
Native American cultures, and historically the Celts and the Greeks) - or they saw wolves
as evil creatures to be removed from the face of the planet at all costs.
Such was the case with America’s settlers in the early 1600s.
At that time the conflict between wolves and people rose from a number of factors, including
fears based off of Old World myth and folklore - but the protection of livestock was one
of the biggest reasons in justifying their removal.
Wolves attacked and ate cows and sheep while their natural prey - bison, deer, and elk
- were depleted by settlers to make room for grazing livestock, and to feed growing human
populations.
And sometimes, like with the eradication of the American bison in the western United States
- prey animals were killed in staggering numbers for fun, as it seemed like nature’s bounty
was endless.
The continual hunting, trapping, and poisoning of wolves- largely encouraged by offering
bounties, and government-supported extermination programs - continued in the United States
for nearly four hundred years, until by the mid-1960s only a single population of gray
wolves remained in Minnesota and Michigan.
It’s likely we would have hunted the wolf to extinction in the United States, were it
not for the creation of the Endangered Species Act by Richard Nixon and congress in 1973.
Grey wolves were listed a year later, in 1974.
Larry Heaney: Forty, fifty years ago-- there were almost no wolves at all anywhere in the
lower 48 states.
Emily: That’s Dr. Larry Heaney.
He’s a curator of mammals here at The Field Museum.
Larry: In the early 1970s, there were maybe 200 wolves in the Great Lakes area.
They had been completely eliminated by the anti-predator programs in the U.S.
Emily: As wolves were eradicated across the continental US between the mid-1800s to
mid-1900s, their former territories opened up and coyotes were given an opportunity.
Wolves tend to kill but don’t eat the coyotes they encounter in the wild, so it’s a wise
coyote that avoids running into a wolf pack.
But in the absence of their top predators, coyotes began spreading out across these newly
unoccupied habitats, leaving western grasslands to occupy eastern deciduous forests.
Unlike wolves, coyotes aren’t seen to be as threatening to people, maybe because they’re
smaller and don’t travel in packs, so they’ve avoided persecution in large numbers.
And compared to wolves, coyotes are inconspicuous, and more difficult to spot and hunt: I suppose
you could say they’re wily.
And they’ve have an incredible ability to adapt to cities-- which are all factors that
have contributed to the success of this species.
After the Endangered Species Act protection of grey wolves their population numbers began
to rise, and individuals spread out from southern Canada and Minnesota.
But this was not necessarily accomplished by a slow distribution: wolves can cover a
lot of ground.
See, in order for a wolf to have the highest chance for succeeding in a pack, it needs
to establish its own territory, otherwise it’ll constantly be competing for food resources.
Therefore, wolves practice a strategy called directional dispersal, meaning they move away
in a single direction from their birth pack- and the distance can be immense.
Larry: It was the young males that were dispersing- sometimes hundreds, maybe a thousand miles
out into territory where there were no wolves.
Emily: Some wolves have been recorded as far as 550 miles away from where they were
born.
Since the wolves in the lower 48 were essentially gone, as these new packs began spreading out
from northern territories, two particular kinds of wolves- the red wolves, and the Eastern
wolves - didn’t encounter female wolves… they encountered coyotes, an animal they would
typically kill.
But without the option to mate with other wolves - because there were no wolves - these
wolves bred with coyotes instead.
Recent research has found that wolves and coyotes in North America diverged from a common
ancestor about 50,000 years ago, which really isn’t that long when we’re talking about
the history of a species.
Since wolves and coyotes are still genetically similar, they’re able to produce offspring
that are fertile themselves.
And here is where things really start to get complicated, BUT FIRST.
Genetic studies based off of museum specimens tell us an enormous amount of information
about the evolutionary history of any number of groups: for example, North American canids.
That genetic material is in the form of tissue samples taken from each individual specimen
when they’re prepared for the collection, and then placed in little vials and kept in
cryogenic storage tanks, frozen in liquid nitrogen.
Study of the evolutionary relationships and history of species is called phylogenetics,
and it uses data collected from specimens in museums, including the study of their sequenced
genomes, to build evolutionary trees.
A genome is the complete genetic material of an organism.
The genomes from several wolves and coyotes in a recent study has allowed scientists to
look at information from 1,000 ancestors of these populations from 20 generations of wolves
and coyotes- resulting in thousands of years of historical information.
In this way, genomes are like time machines, helping us to understand evolutionary ancestry.
But a genome can only tell us so much: other questions are answered by looking
at individual specimens.
The Field Museum has one of the largest collections of full wolf skeletons in the world.
For a time, mammalogists believed that most questions about an organism could be answered
by looking at its pelt and its skull alone - not always examining the other bones in
its body.
And that’s pretty convenient, ‘cuz big skeletons take up a lot of space in drawers,
so they could store more specimens if they only kept the skull.
It’s also true that examining a skull’s unique characteristics like teeth and inner
ear bones, as well as its overall shape and size, can help scientists differentiate one
species from another.
Here at The Field Museum, assistant collections manager and taxidermist Tom Gnoske has been
taking in animals like wolves and coyotes for decades.
These specimens, with their pelts and complete skeletons, have provided important information
for recent studies.
And they help us understand the transformations of native dogs in north america over the last
tens to hundreds of thousands of years.
He recently invited me up to the prep lab to see for myself.
Emily: Can you talk a little bit about the process of making a case skin, and why we
decided to go that route instead?
Tom: It’s sort of a traditional taxidermy - and, one being that you’d leave the claws
in on the one side- and you’d leave the last digit with the skeleton on the other
side, so that you’d get the maximum potential benefit or use out of each specimen.
Some of those things we were just doing because it may be valuable to somebody.
Emily: What is really separating these two, and making them “different”?
Tom: Where you really see that is when you look at domestic dogs.
Even the dog that you may think is tall- they’ve got very significant proportional difference
to a coyote and a wolf.
But when you see them with their skin off, they’re like machines.
Their ligaments and their tendons are massive, their nails are massive, their teeth are massive.
You see - in the process of preparing them- and you do enough of them, you start to see
patterns over- like, over the first twenty of them, I started thinking, god, these are
really different than domestic dogs.
Emily: We have got a ton of footage of the skinning process for these two specimens
and we’re going to post that in a separate video because we know how much you guys like
that stuff, but first we have got to get up to date on the status of wolves and coyotes.
In 2012, US Fish and Wildlife published a monograph detailing just how many different
kinds of wolves had lived, or now live in the United States, because honestly the literature
on the topic is all over the place.
Up until that point, the most comprehensive reviews had determined 2 species of wolves
- the gray wolf and the red wolf - and between 8 and 27 different subspecies in North America.
Like, talk about a lack of consensus, but this review in 2012 confirmed that a proposed
third species - the eastern wolf - was unique enough to be valid, too.
Although now… that may no longer be the case.
A paper published last year looked at the genomes of both red wolves and eastern wolves,
and discovered that these two types have more coyote DNA than wolf DNA in them.
The authors argue, red and eastern wolves are not distinct lineages of wolves: what
makes them unique is that they’re hybrids.
The genomic study showed that eastern wolves were really just half gray wolf, half coyote-
the red wolves were comprised of 75% coyote DNA.
There are real-world consequences for this confusion.
Government protection right now in the US are based on clear, definite taxonomy,
and right now, there is no clear, definite taxonomy.
The Endangered Species Act has no policy for hybrids.
Even if hybrids were recognized, how much DNA from an endangered species would you need
to qualify for protection?
Half… or a quarter?
Twelve percent?
And it’s impossible to prevent hybridization from occurring in the wild without concerted
efforts to manage these, uh, encounters. Maybe in this case, hybridization is simply a natural
response to the dramatic changes we’ve inflicted on the ecosystems of both coyotes and wolves.
Larry: Legal systems don’t do well with complexity.
Emily: (laughs) No.
Larry: They don’t do well with change.
Emily: What does that mean for conservation and research?
Larry: A couple of examples: the Upper Peninsula of Michigan is recognized as having wolves.
The lower peninsula of Michigan has animals that look a lot like wolves, and sound like
wolves, and function like them to a pretty fair degree -- but they probably are thirty,
forty, maybe fifty percent coyote.
There had been research done by the Michigan DNR up to the point of discovering that they
were significantly hybridizing with coyotes.
And at that point - because of the way the state laws and budget restrictions are written
- they could not do any more research on them, because they’re not wolves.
They’re hybrids.
Emily: So you get the results back and it says, congratulations, you have a wolf-coyote
hybrid- and then it’s just like a hot potato?
They’ve just got to drop it and walk away?
Larry: Apparently, that’s the way -- at least to some significant degree - that’s
the way that it’s worked.
Emily: If the ESA doesn’t recognized hybrids… then what are we really protecting?
The wolf we skinned in Montana had more ‘pure’ grey wolf DNA than the red wolf and the eastern
wolf, but it’s the Mexican wolf subspecies that has the lowest amount of genetic diversity
because they’re largely inbred through captive breeding programs in an effort to retain that
genetic purity.
And those programs have seen a lot of success, too.
The Brookfield Zoo in Chicago is one of many agencies involved in a captive
breeding and reintroduction program for the Mexican wolf- so, we went to go talk with
the zoo’s associate curator of mammals, Joan Daniels, about their involvement in the project.
Joan Daniels: We built our new exhibit around the recovery program for the Mexican wolves,
and brought them in 2004.
Emily: So, how is the population doing today?
You said it’s been doing a lot better than it has been historically.
Joan: It is doing a lot better but it’s because of the recovery program, and the effort
of zoos in both Mexico and the United States- and the reintroduction program that was started
in the late 1990s has now become so successful that there’s close to a hundred wolves that
have been reestablished in Arizona and New Mexico.
Emily: So, do you see this kind of model as the future of establishing populations, or reestablishing
populations?
Joan: It’s a really good model, and as you said in North America we have a number
of wolf subspecies that are endangered- and having them out of the environment, really
affects the environment.
We need wolves in our ecosystems.
Emily: But just because red wolves and eastern wolves have a good amount of coyote DNA in
their genes doesn’t mean they’re not worthy of protection, too: after all, a portion of
their genetic makeup is from a species that remains endangered, at least in numbers.
Today, there are no population numbers of wolves in the U.S anywhere near what
they were pre-eradication; in 2015, U.S. Fish and Wildlife estimated there were around 5,500
wolves in the lower 48 states.
And in January, they proposed an updated recovery plan for the last 50 red wolves in North Carolina
- so there are still conservation efforts moving ahead.
The complications in this situation are bred from the same issues that resulted in the elimination of
wolves in the first place- and that is, for better or worse, we are trying to control
nature, either through the directed elimination of a species, or by the strict management
of it's population growth.
Hybridization events continue to crop up in wolf populations around the U.S. faster than
can be detected through monitoring programs and genomic studies.
Because the legal framework for protection for these animals is so rigidly based off
of very clear taxonomic lines that don’t always exist, movement or progress in any direction
within that structure is difficult, if not completely impossible.
Despite hitting walls when it comes to securing research funding for studying hybrids, or
an inability to draw legal boundary lines around a species’ protections, one
thing is certain: the stream of science is relentless.
Larry: Science attempts to tell us what is.
Science doesn’t deal with what “should” be.
That’s a decision that we make.
Science provides us with information.
We then decide what to do with that information.
These are issues that we are going to have to grapple with as a society- and decide how
we’re going to modify our rigid laws, which - in order to be clear and applicable - have
to be rigid.
Emily: Hey!
This episode of The Brain Scoop was produced and directed by Brandon Brungard and Sheheryar
Ahsan, with production assistant help by our intern Laurel Tilton, and it was written and
hosted by yours truly.
We had collections access and research help from Larry Heaney, Tom Gnoske, Kayleigh Kueffner,
Lauren Smith, Caleb McMahan, Roland Kays, and Gretchen Rings.
We had help here at the Brookfield Zoo by Sondra Katzen and Joan Daniels- and The Brain
Scoop is brought to you by The Field Museum in Chicago, Illinois.
I think I got everybody!
… it still has brains on it.