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Episode 277: Rewilding Scotland

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This week is Caitie Sith and Dave’s episode! They want to learn about animals reintroduced to Scotland, especially the Highland wildcat!

The Scottish (or Highland) wildcat:

The Eurasian lynx:

The Eurasian beaver (with babies!):

The white-tailed eagle:

Reindeer in Scotland:

The pine marten:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week is Caitie Sith and Dave’s episode, where we’ll learn about the re-wilding of Scotland! Re-wilding is the process of restoring an ecosystem to its natural state, basically reversing habitat loss. Most of the time there’s a lot more to it than just reintroducing native animals, but sometimes that’s all that’s required.

Scotland is a part of the island of Great Britain, north of England. People have lived there since the last glaciers melted at the end of the Pleistocene, around 12,000 years ago. During the Pleistocene and a few thousand years after the glaciers melted, Scotland was connected to Europe by a lot of marshy land where today there’s ocean, and naturally many animals lived in Scotland that were also found in Europe at the time. Some of the ice age megafauna that lived in Scotland included the woolly rhinoceros, woolly mammoth, bison, aurochs, wild boar, saiga antelope, giant deer, red deer, reindeer, moose, wild horse, beaver, walrus, Polar bear, brown bear, lynx, wolf, Arctic fox, and cave lion. Many fossil and subfossil remains of Pleistocene animals were destroyed by the formation and movement of thick glacier ice, which scoured the land down to bedrock in many places, so those are only the animals we know for sure lived in Scotland.

But Scotland wasn’t covered by glaciers all the time. The Pleistocene wasn’t a single ice age but a series of cold events interspersed with warming trends. During these interglacial periods, which lasted some 10- to 15,000 years at a time, animals would move to Scotland from other places or become more numerous than before. Then the climate would start cooling again, glaciers would slowly form over many years, and animals would move to areas where there was more food. This happened repeatedly over a period of more than 2.5 million years.

In other words, while we have some fossils of Pleistocene animals that once lived in Scotland, we don’t have nearly as many as have been found in England, Ireland, and Wales. But what we do know is that Scotland was once teeming with all kinds of animals we’d never associate with the country today, like cave lions and Polar bears!

Much of the ice age megafauna went extinct around 12,000 years ago when the last glaciers melted and the climate started warming. Cold-adapted animals couldn’t always survive in a warmer climate, not to mention that as the climate changed, the types of plants available to eat changed too. Some animals migrated away or went extinct, while some were able to stay in Scotland successfully. This included the red deer, reindeer, wild boar, walrus, brown bear, and lynx.

If you’re wondering why that list is full of animals that don’t actually live in Scotland these days, like the brown bear and lynx, it’s because humans hunted many of the native Scottish animals to extinction. Others went extinct due to habitat loss or competition with introduced animals. Many surviving species are endangered today for the same reasons.

For example, the Scottish wildcat, also called the Highland wildcat. We talked about it briefly in episode 52 way back in early 2018. One of the animals that migrated to Scotland after the Pleistocene, but before sea levels rose and cut the British Isles off from Europe, was the European wildcat. The Scottish population has been separated from the European population for at least 7,000 years, and some researchers think it should be classified as a subspecies of European wildcat.

The Scottish wildcat is a little larger than a domestic cat and is always tabby striped. It has a bushy tail with a black tip, a striped face and legs, never any white markings, and is usually dark in color with black paws. It’s a solitary animal that mostly lives in woodlands, where it eats mice, voles, and other rodents, rabbits, and birds. It used to be common throughout much of the British Isles, but these days it’s only found in parts of Scotland.

You’d think people would be excited to have a genuine wildcat living in their country, since wildcats are pretty awesome and eat animals that can damage crops. But for some reason, until recently people thought these wildcats were pests and would shoot them on sight. Some people thought the wildcats were killing game birds, which is rare, or that they were dangerous, which isn’t true. At the same time, the people shooting wildcats were letting their domestic cats roam freely, which has caused an even bigger problem to wildcats than getting shot at.

Like other wildcat species, the Scottish wildcat can and will cross-breed with domestic cats. The resulting kittens are fertile, meaning they can have babies with either wildcats or domestic cats. Kittens are great, of course, but domestic cats are a different species from wildcats. Hybrid cats are less suited to live in the wild, but too wild to be good pets, and if too many domestic cats breed with wildcats, soon there won’t be any real wildcats left. Not only that, domestic cats carry diseases that wildcats can catch.

The Scottish wildcat is a protected species these days, with conservation efforts in place to keep the wildcats and their habitat as safe as possible. One important step is to encourage people to get their domestic cats neutered. This is healthier for pet cats anyway and will help keep tomcats from spraying and fighting, and of course it stops them from having kittens with wildcats.

Another felid that once lived in Scotland is the Eurasian lynx. It still lives in parts of Asia and Europe, but it went extinct in Scotland several hundred years ago, mainly due to deforestation and hunting for its fur. It’s about 28 inches tall at the shoulder, or 70 cm, and is a heavily built animal with thick spotted fur and a short bobtail. The tip of its tail is black although the rest of the animal is mostly tan or brown with darker brown spots, and it has long black tufts of fur on the tips of its ears. It’s slightly bigger than the related Canadian lynx.

Conservationists have wanted to reintroduce the Eurasian lynx to Scotland for years. Since the lynx is threatened in the rest of its range by habitat loss and hunting, reintroducing it to its former range in Scotland would help it and the ecosystem in general. With no large predators to keep their numbers in check, the population of roe deer in Scotland is too high to be healthy, and the lynx loves to eat roe deer.

Some people worry that if the lynx is reintroduced to Scotland, it will be dangerous to humans and livestock. But the lynx is a shy, solitary animal that avoids humans as much as possible. There are enough roe deer alone to sustain a population of over 400 lynxes in the wilder parts of Scotland, especially in the Highlands. The lynx also spends almost all of its time in forests and doesn’t like open pastures. It’s been successfully reintroduced to its former range in other countries, with a nice side effect being increased tourism to national parks where it’s now found.

Scotland also used to have beavers, which were hunted to extinction in the 16th or 17th century. Then, in 2009, the Eurasian beaver was reintroduced to parts of Scotland and is doing great! There are more than 1,000 beavers living in Scotland now. Beavers are considered a keystone species, a term we haven’t really examined on the podcast before, but it means that an animal is so important to an ecosystem that if it goes extinct in an area, the ecosystem sort of falls apart and many other animals go locally extinct soon after.

Beaver ponds create a winter habitat for many types of fish, and beaver dams don’t stop fish like salmon that migrate upriver to spawn. The dams help reduce flooding, improve water quality, and create cover for lots of fish and other animals.

Naturally, though, some people complain about the beavers, because there will always be someone who complains about anything. Some people think beavers eat fish and will eat up all the fish that humans want to catch. Beavers actually don’t eat fish at all, they only eat plant material. Some people think beavers carry the giardia parasite, which causes a bacterial infection sometimes called beaver fever that’s spread in water, but giardia is actually mostly spread by domestic dogs. Some people complain that beavers fell trees and build ponds, and both these things are true. But the beaver is just doing what it’s supposed to do, and as we just learned, this tree felling and pond-making are good for the environment—unlike humans, who chop down lots of trees and make artificial ponds when landscaping, while simultaneously draining wetlands, which doesn’t help the local environment at all. Besides, the beavers are cute and attract tourists who want to get pictures of them, which is also good for the local economy. Everybody wins when there are beavers around, is what I’m trying to say.

The beavers reintroduced in 2009 aren’t the only beavers in Scotland. In 2001, people started seeing them around the river Tay—but no one knew where they came from. Well, presumably someone knew, because the beavers didn’t get there without help. If this reminds you of episode 48, where we talked about some mystery beavers that appeared in Devon, England, the Devon beavers showed up in 2013, twelve years after the Scottish mystery beavers. At first the Scottish government planned to capture the Tayside beavers and keep them in captivity, but the beavers are still there and doing very well.

It’s great that over a thousand beavers live in Scotland now, but that’s actually not very many. Still, it’s a whole lot better than the number of Eurasian beavers about 150 years ago, when researchers think there may have been as few as 300 individuals alive in the whole world.

Another animal that once lived in Scotland, was hunted to extinction, and then mysteriously reappeared recently is the wild boar. They first appeared in the 1990s and by now there are thousands of them in Scotland. It’s possible they escaped from farms, where they’re sometimes raised for meat like domestic pigs. While they’re a native species, they don’t have any predators in Scotland and are causing a lot of damage as they become more numerous. The wild boar’s natural predator is the wolf, and the last wolf in Scotland was killed in 1743. Lynxes will also kill wild boar piglets.

Some birds have been reintroduced to Scotland too. The white-tailed eagle is a type of sea eagle, closely related to the bald eagle of North America although it’s slightly larger than the bald eagle. The biggest ever reliably measured was a specimen from Greenland with a wingspan of 8 feet 4 inches across, or 2.53 meters, just a smidge larger than the largest bald eagle wingspan known. It’s mostly brown and gray with a yellow bill and feet, and a white tail. It lives around water and eats a lot of fish, but it also eats lots of carrion, gulls and other birds, and occasionally small mammals like rabbits. It always lives near water but it prefers wooded areas, especially lowlands and forested islands.

The white-tailed eagle went extinct throughout Britain in the early 20th century when people decided they wanted all those fish the eagle eats for themselves. Never mind that even a thousand eagles couldn’t eat as many fish that a single commercial fishing boat catches in a day. People also decided that eagles killed lambs, even though this is extremely rare. White-tailed eagles would much rather eat fish and seagulls than lamb. The last white-tailed eagles in Scotland were shot and killed in 1916.

As if that wasn’t bad enough, white-tailed eagles were also killed throughout the rest of their range and were especially vulnerable to the chemical called DDT. DDT was a popular pesticide developed in the 1950s and used to kill insects on crops and gardens. But DDT is dangerous, because like other pesticides it doesn’t just do its job and evaporate. It stays in the environment and ends up in the bodies of animals, including people. It’s especially bad for birds that eat a lot of fish, since a lot of pesticides end up in the water, and it causes their eggshells to become so thin and weak that the eggs break when the mother tries to keep them warm. This is the same thing that almost drove the bald eagle to extinction in North America. By the time DDT use was banned in many countries and the white-tailed eagle was declared a protected species, it was almost too late.

Conservation efforts have helped stop the white-tailed eagle from going extinct and its numbers are slowly growing. Starting in 1975, young eagles were brought from Norway to Scotland, where they were successfully reintroduced in the inner Hebrides islands and have now expanded to other parts of Scotland. Some people still complain about the eagles and sometimes shoot or poison them even though it’s illegal, but most people are happy to have them around, especially birdwatchers.

Scotland even has some reindeer these days. Reindeer probably lived in Scotland until around the 12th century, and in 1952 a Swiss herdsman thought they should still be there. He brought a small herd to the Cairngorm mountains, which is now a national park. The reindeer are semi-domesticated but roam free, and they attract tourists who hope to catch a glimpse of them.

At the same time that many native animals have gone extinct, lots of non-native animals have been introduced to Scotland, including wallabies, American mink, gray squirrels, various species of crayfish, and many more. Conservationists are working to minimize the damage these introduced species cause. Many invasive species were animals kept as pets that either escaped or were released into the wild. We talked about the invasive eastern gray squirrel versus the native red squirrel in episode 241, for instance. People released gray squirrels into parks in England because they were so cute, and a hundred years later, the gray squirrels are taking over in many places. They’re increasingly common in Scotland, although Scotland has a small predator called the pine marten that loves to eat squirrels.

The pine marten is a type of mustelid, or weasel relative, that’s common throughout much of Europe and Asia. It grows about two and a half feet long, or 75 cm, including its bushy tail. It mostly lives in wooded areas and spends a lot of its time in trees, hunting squirrels and other small animals like frogs, insects, and birds. It will also eat carrion, bird eggs, and sometimes fruit. It’s mostly brown with a cream-colored throat. It even has partially retractable claws like a cat to help it climb trees, although it’s not related to the cat.

The pine marten is especially good at catching squirrels, and it tends to target the gray squirrel because it’s easier to catch. The red squirrel is more cautious. Where there are pine martens, there are fewer or no gray squirrels. The problem is, the pine marten is considered a pest that kills game birds, so some people shoot or poison it even though it’s a protected species. Then those same people complain about all the gray squirrels around. The pine marten is doing well in many parts of Scotland, though, and has even expanded its range slightly in the last few years.

Scotland is a beautiful country known for its wild and rugged countryside. It wouldn’t take much to rewild it properly, a process that’s well underway with keystone species like beavers already re-established in many places. The main problem is people who don’t understand that a healthy ecosystem requires predators. Without lynxes, wolves, bears, and other large predators, animals like roe deer and wild boar become so numerous that they can’t find enough to eat and either starve or destroy crops and gardens.

Fortunately, many more people in Scotland do understand the importance of building healthy ecosystems. After all, they’re naturally proud of where they live and want to make it even better.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 048: Out of Place Animals

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Happy New Year! Let’s learn about a few animals that have shown up in places where they just shouldn’t be. How did they get there, and why? Sometimes we know, sometimes it remains a mystery.

Some of Pablo Escobar’s hippos:

King Julien, the ring-tailed lemur who was discovered almost frozen to death in London:

A little alligator captured in a koi pond. In Maryland. Which is not where gators live:

A monk parakeet eating pizza in Brooklyn, because of course it is:

How did these beavers get into a Devon river? They’re not telling:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Happy new year! Let’s ring in the new year with some out-of-place animals. Sometimes an animal shows up in a place where it just shouldn’t be, and while the animal itself isn’t a mystery, how it got there is. In this episode we’ll chase down the solutions to a few of these mysteries, and ponder a few others we can’t solve.

We’ll start with some hippos that aren’t hanging out in Africa where they belong, but are living in Columbia, South America. In this case, we do know what happened. Back in the 1980s, a guy named Pablo Escobar had a private zoo that contained four hippos, along with other animals. Escobar was not a nice person. He was a drug lord who grew obscenely rich from selling cocaine and killing anyone who didn’t agree with him. In 1993 the police raided his estate and Escobar was killed in a shoot-out. The government took over the estate and turned it into a park, and most of the animals were given to zoos. But the hippos stayed. The estate had a lake that they lived in, and they weren’t hurting anything.

But after a few decades, the four hippos turned into forty. The hippos have expanded their range from the park to neighboring rivers. Sometimes a hippo wanders into a neighboring town or ranch. Hippos can be dangerous—in fact, they’re the most dangerous animal in Africa, killing more people than any other animal. But the locals like the hippos. At this point the government is torn between needing to keep the people and environment safe from these out-of-place animals, and preserving animals that everyone agrees are really awesome. In 2010 the government started a program to castrate the males, which will stop the population from growing, although castrating a wild hippo is not easy so the program is not necessarily going to work.

This is what a hippo sounds like:

[hippo sound]

In December 2011, someone found an unusual animal in London, a ring-tailed lemur. Even if you don’t know what it is, you know what it is. The vets who treated the animal named him King Julien after the character from the movie Madagascar. Lemurs are primates, only found in the island country of Madagascar, so what was one doing in London on a below-freezing day? Poor King Julien almost died of hypothermia and dehydration.

King Julien was very tame, so had probably been someone’s pet. People are allowed to own lemurs in England, but only with a special license. Ring-tailed lemurs are popular exotic pets, and part of the reason they’re endangered in the wild is because they’re frequently captured for sale on the black market. I tried to find out what had happened to King Julien, without luck, but hopefully he recovered fully and now lives in a zoo or wildlife sanctuary where he can be properly cared for and can hang out with other lemurs.

This is what a ring-tailed lemur sounds like:

[ring-tailed lemur sound]

Unfortunately for many animals kept as exotic pets, once the people who buy them realize owning an alligator, for instance, is not as fun as it sounds, the animals are often just dumped outside to fend for themselves. The kind of person who would buy an exotic animal in the first place is probably not the kind of person who bothers to learn how to take care of it.

Back in the mid-20th century, if you took a vacation to Florida and went into a souvenir shop, you could buy a live baby alligator for a few bucks. Baby alligators are cute, like big lizards. But they grow fast, they eat a lot, they make a mess, and they often get sick because they’re not properly taken care of. I like to think I know a fair amount about animals, but I wouldn’t know how to take care of a baby alligator. And if it was 1950 and I couldn’t just look that information up online, or find it in the local library, I’d probably not do a very good job.

Now I know you’ve heard about sewer alligators. The story goes that back in the days when baby alligators were cheap pets, people would bring them home as souvenirs, realize very soon that they didn’t actually want an alligator as a pet, and would flush them down the toilet to get rid of them. Some of the flushed baby alligators survived, and grew up in the safety and relative warmth of the New York City sewers, eating rats. Every so often a maintenance worker would get the shock of shining a flashlight down a sewer tunnel and seeing the reflection of alligator eyes. In the stories, the gators were always enormous.

So did this ever happen? Did alligators ever really live in the sewers of New York or any other city? Alligators have actually been found in sewers, although it’s not known if they were survivors of being flushed or if they were released aboveground and found their way to the nearest water through storm drains. In 2010 a two-foot-long, or 60-centimeter, baby alligator was found in the sewer in New York City. In 1984 a Nile crocodile was captured in the Paris sewers. But a sewer is not a good habitat for any living thing, especially not a reptile. Any alligators found in sewers haven’t been there long—they wouldn’t survive long, and they certainly couldn’t breed in a cold, lightless environment.

But alligators don’t just turn up in sewers. They’re forever being found in people’s ponds, and not in Florida or surrounding areas like you’d think. As just one of many possible examples, in 2015 a guy in Maryland, in the northeastern United States, found a three foot, or .9 meter, alligator in his koi pond. Probably he did not have any koi left by the time police officers caught the gator and relocated it to a local zoo.

This is what an American alligator sounds like:

[alligator sound]

It’s not too unusual to find a bird somewhere outside of its natural range. While migrating birds have amazing skills at navigating long distances, sometimes a bird is blown off course by a storm, or joins a flock of closely related birds that then fly somewhere other than its usual migration route. But sometimes the presence of out-of-place birds aren’t so easy to figure out.

For instance, the Brooklyn parrots. Brooklyn is part of New York City, not a particularly welcoming place for tropical birds. But there’s a population of wild parrots called monk parakeets, or Quaker parrots, that have been living in the city for over 50 years. And no one’s sure where they came from.

The monk parakeet is from Argentina. It’s smallish, around 11 inches long or 29 cm, with a 19 inch wingspan, or 48 cm. It’s a cheerful bright green in color with pale gray forehead and breast, and some blue on the wings. It eats plants of all kinds and builds elaborate multi-family nests called apartments by weaving twigs together.

It’s also been a popular pet for a long time. It learns to mimic speech easily, is intelligent and hardy, and lives 15 to 20 years, or even longer. But because so many feral populations have developed in North America and Australia, some areas no longer allow monk parakeets as pets at all.

The Brooklyn parrots are probably escaped birds from pet stores and especially from shipping crates full of birds imported from Argentina. Thousands of the parrots were sold as pets in the United States during the 60s and 70s. The first report of parrots living in New York City comes from December 1970, when an article about them appeared in the New York Times. Since then, the origin of the parrots has achieved urban legend status, with unsubstantiated stories of heroic releases of captive birds from sinking cargo ships, a mass release of captive birds from an abandoned aviary, and so forth. In the mid-2000s, a poaching ring trapped birds to sell on the black market, but the ring was busted and the birds freed.

Populations of monk parakeets also live in Chicago, Austin TX, Brussels, Belgium, and many other cities. Because their droppings don’t harm statues and other structures the way pigeon droppings do, and studies of urban birds reveal that they aren’t a threat to native species, many cities have stopped trying to exterminate the birds. Their large nests do frequently have to be removed from power transformers.

This is what a monk parakeet sounds like:

[monk parakeet sound]

I always think of beavers as a North American animal, but the Eurasian beaver is native to—you guessed it—Europe and Asia. But like the North American beaver, the Eurasian beaver was almost driven to extinction by humans, who wanted its fur and a substance called castoreum that is still used in perfumes and cigarettes. Castoreum is produced by the beaver to scent mark their territory, and a beaver’s castor sacs is found right next to the anal glands. Another reason to quit smoking!

So by 1900, the Eurasian beaver was almost extinct throughout its range. Only a few small populations remained. In England, Scotland, and Wales it went extinct completely by the 16th century. But after conservation efforts throughout Europe and Asia, beavers have started to be reintroduced into their historic ranges. The first official reintroduction of beavers into Scotland occurred in 2009 and the animals are doing well.

In 2013, people in Devon, England started seeing beavers along the River Otter. The next year they had babies. No one had any idea where the beavers had come from—Devon is too far from Scotland for the Scottish beavers to have migrated there naturally, and anyway the Scottish beavers are closely monitored. If three had gone missing, the researchers in charge of them would know.

It led to a lot of controversy in Devon, to say the least. Fishers and farmers worried that the beavers would mess up the river, carry diseases, and in general cause havoc. And since the beavers hadn’t been officially introduced, no one knew whether these were even the right kind of beaver for England and if they were healthy. But locals liked having beavers around—they are really cute animals, after all. When the government agency Natural England announced it would capture the beavers and put them in a zoo, locals protested so strenuously that the plan was changed. Instead, the beavers were captured, examined by veterinarians to make sure they were Eurasian beavers and disease free, and rereleased. This happened in 2015. The beavers were healthy, they were the right species, and they were returned to the river. Still, no one one knows how they got there.

Beavers are actually good for fish and the local environment. Beaver ponds create winter habitat for many types of fish, and beaver dams don’t stop fish like salmon that migrate upriver to spawn. The presence of beaver dams helps reduce flooding, improves water quality, and creates cover for lots of fish and animals. And while some people believe beavers spread the giardia parasite, which causes a bacterial infection sometimes called beaver fever, giardia is actually mostly spread by humans and our domesticated animals, especially dogs. Giardiasis causes nasty diarrhea and other intestinal distress that can go on for weeks, and it’s why you don’t ever drink water that hasn’t been treated in some way.

The beavers in Devon are doing well and have spread into neighboring waterways. They got in the news again a little over a year ago, in October of 2016, when a rich guy decided he didn’t like them. Sir Benjamin Slade, who has a great name but who is clearly a prime jerk, posted a reward of 1,000 pounds to anyone who would kill the beavers who’d moved onto his estate, because he didn’t like that they were felling some of his trees. Dude, you are rich. Hire somebody to plant more trees for you. Besides, beavers have brought tourists to Devon who hope to catch a glimpse of the animals, which helps the local economy, Mr. Slade, if that IS your real name.

Anyway, this is what a beaver sounds like:

[beaver sound]

There are so many out-of-place animal reports that there’s no way to cover more than a few in one episode, so I’ll definitely revisit the topic. Until then, keep an eye out for anything unusual walking through your back yard.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!