If you went looking for a place to replenish the dwindling numbers of a nearly extinct
species, the area surrounding a nuclear disaster probably wouldn't be your first Zillow search.
And yet Przewalski's horses have found a place to do just that inside the Chernobyl Exclusion
Zone.
Hi, I’m Erin McCarthy, and this is The List Show.
The early morning of April 26, 1986 saw what is often considered the worst nuclear disaster
in human history.
A faulty design and improperly trained workers are two of the precipitating factors that
led to an explosion in Reactor 4 of the Chernobyl nuclear power plant.
The total amount of radioactive material eventually released was hundreds of times higher than
seen in the atomic bombing of Hiroshima.
Scientists are still reaching conclusions about the long-term impacts of the disaster.
But rather than eliminating all wildlife in the vicinity, as you might expect, the tragedy
has, in some ways, created the conditions for some fauna to thrive.
Today I’m sharing surprising facts about the animals of Chernobyl.
I’ll talk about how these mutants might not look like what you’d expect and share
the good (like those horses), the bad (like decimated insect populations), and the cuddly—who
wants to adopt a Chernobyl puppy?!
Let’s get started.
The Smithsonian’s National Zoo & Conservation Biology Institute called Przewalski's horses
“the last truly wild horse.”
Other species sometimes referred to as wild, like the kind you might find on the United
States’ Assateague Island National Seashore, are properly classified as feral domestic
horses—they descend from horses that escaped domestication.
Whether Przewalski horses—also called takhi—can truly be called a wild species or subspecies
is actually a matter of some debate.
But what’s clear is that a once-large population that ranged across large swaths of Asia and
Europe was eventually reduced to almost nothing.
When Lee Boyd and Katherine A. Houpt edited a book about the animal in 1994, the most
recent wild sighting had occurred in the late ‘60s, leading the authors to declare them
“extinct in the wild.”
In 1998, around 30 of the horses were released in the Chernobyl Exclusion Zone.
In the years since, that population has increased to more than 200.
Some of the original animals released into the area lived for decades, as seen on camera
traps; they also reproduced in the wild, leading to new generations.
As the head of the scientific department of the Chernobyl nature reserve, told Phys.org,
"Paradoxically, this is a unique opportunity to preserve biodiversity.”
In the case of the Przewalski’s horses, the animals were introduced years after the
disaster at reactor Number 4.
But according to biologist Jim Beasley, the population of large mammals in the exclusion
zone has surpassed the numbers found before the near-meltdown.
With limited human activity in the area for decades now, it’s all a little bit like
those scenes from a disaster movie where nature starts to retake a city.
Moose, deer, wolves, and beavers are just some of the species that have seemed to find
a happy home in the radioactive area.
A constant dose of low-level radiation obviously isn’t beneficial, but it may be the case—for
some animals, at least—that it isn’t harmful enough to outweigh the pre-disaster impact
of human beings encroaching on habitats and actively hunting wildlife.
Wolves, in particular, may benefit from their propensity to travel great distances, giving
them the opportunity to dilute the amount of radiation consumed during hunting.
Beasley pegged the population density of the Chernobyl wolves as significantly higher than
that found in America’s Yellowstone National Park.
As Beasley sees it, “ … humans have been removed from the system and this greatly overshadows
any of those potential radiation effects.”
Beasley’s conclusion is obviously an informed one, but there isn’t universal consensus
that it’s correct.
No one outside of Peter Parker is arguing that radiation is good for you, but there’s
disagreement over just how harmful particular levels are in comparison to other environmental
factors.
It may be a matter of which species you’re focusing on.
A 2009 paper in Biology Letters pointed to severely reduced insect and spider populations
two decades after the nuclear disaster, a trend that was particularly pronounced in
the areas with the highest levels of radiation.
Similar effects were seen in the aftermath of Japan’s Fukushima disaster.
A 2011 paper published in Biological Conservation estimated that plants and animals in the area
had up to 20 times the rate of genetic mutations of species not subjected to these high levels
of radiation.
In 2018, scientist Michael Byrne tracked a wolf traveling a great distance—ultimately
outside of the Exclusion Zone—and wondered whether the disproportionately high number
of mutations in the Chernobyl animals could be passed on to other populations.
Byrne was even-handed in his speculation: “I don’t want to say that animals from
Chernobyl are contaminating the world.
But if there are any forms of mutations that could be passed on, it’s a thing to consider.”
That doesn’t mean there’s a bunch of three-eyed fish or two-headed cows in the Exclusion Zone,
though.
In 2016, footage of some very large catfish in the cooling pond of the Chernobyl reactor
spread online, leading some to conclude that the radiation had supercharged the fishes’
growth.
It’s doubtful that the mutations caused by radiation, though, would lead to a larger
overall size.
These types of mutations generally decrease an animal’s fitness and ability to grow
to full size, let alone some kind of Hulk-like supersize.
The explanation for the large catfish was actually quite simple: some fish are just
really big.
It seems that the most dramatic genetic mutations occurred immediately after the explosion at
Reactor Number Four, consistent with what we’ve observed in human beings.
About 30 people died within months of the original explosion, primarily from acute radiation
syndrome.
Longer-term deaths related to the disaster are a matter of considerable debate, though
there is evidence that thyroid cancer rates were elevated in people (especially children)
exposed to Chernobyl’s radiation—possibly through contaminated food.
Perhaps surprisingly, a study published in the journal Science showed that parents who
experienced genetic mutations as a result of radiation exposure did not pass those mutations
on to their children.
It makes some sense that the biggest impacts would be felt in the immediate aftermath of
the disaster, given how radiation works.
Over the years, some of the potentially harmful radionuclides released by the blast have decayed,
presumably making the area less dangerous to live in.
Uncontrolled iodine-131 exposure, for example, is known to increase the risk of thyroid disease,
including cancer.
But it has a halflife of only eight days, and would have basically disappeared from
the zone within a few months.
Other radioactive isotopes are still present in significant quantities.
Cesium-137, for example, has a half life of over 30 years.
And some animals are disproportionately affected.
One risk factor is the animal’s diet.
Voles, for example, are a type of adorable little rodent that likes to eat a lot of mushrooms.
Unfortunately, some mushroom species happen to be particularly good at concentrating radiation,
passing on the harmful material to hungry voles.
Sure enough, voles seem to demonstrate the harmful effects of radiation in a number of
ways.
The critters were shown to be less fertile in areas with higher concentrations of radiation,
with a corresponding drop in overall populations.
They were also shown to have higher rates of cataracts than animals from outside the
Exclusion Zone.
Motion to get some surgical ophthalmology for the Chernobyl voles!
Barn swallows in the area were shown to demonstrate elevated levels of partial albinism, presumably
a result of radiation-related genetic mutations.
Areas with higher levels of radiation also seemingly gave rise to bird populations with
smaller brains, less viable sperm, and decreased species diversity and abundance.
So no—the story of Chernobyl’s animals isn’t a simple one of the land returning
to some kind of fecund paradise—but it also isn’t the barren wasteland you might’ve
imagined before starting this video.
In addition to all the wild animals we’ve discussed, the Exclusion Zone is also home
to hundreds of feral dogs—descendants of pets that were sadly, if understandably, abandoned
in the aftermath of the catastrophe.
At one point authorities tried to kill the strays.
When that didn’t work, the canine populations grew unchecked for a number of years.
Now, an organization called the Clean Future Fund helps conduct sterilization campaigns
in the area.
They also provide medical care, vaccinations, and even food to the Chernobyl pups (and cats).
Back in 2018 and 2019, a number of dogs were identified as having safe levels of radiation,
and a few dozen were actually adopted.
It seems that the 1-2 punch of the pandemic and the Russian invasion of Ukraine have disrupted
the organization’s efforts, though they do continue to do occasional work in the Exclusion
Zone.
Some of the Chernobyl dogs have been adopted by people who, themselves, live in the Exclusion
Zone.
This video was mostly about non-human animals, but I wanted to end on the most surprising
thing, for me, that came up in researching this script.
Despite laws ostensibly prohibiting it, there are actually a number of human beings living
in the Exclusion Zone, some with tacit permission from authorities.
These residents are called samosely, or self settlers.
They’re mostly seniors, mostly women, and mostly lived in the area before the nuclear
disaster.
For any number of reasons, the samosely have decided that the potential risks of radiation
are outweighed by other considerations—financial, cultural, and geopolitical—that called them
to the area.
That’s it for this episode of The List Show.
If there’s another interesting part of the world that we should make a list about, tell
us about it in the comments below.
Thanks for watching!