Feeds:
Posts
Comments

Posts Tagged ‘reindeer’

rudolph isn't a reindeer

This is a reindeer:

reindeer

And Neil deGrasse Tyson drops a fact bomb:

neil degrasse tyson reindeer

 

Read Full Post »

From left to right: Siberian musk deer (which isn't a true deer), Reeves's muntjac, and a Western roe deer.

The notion of tusked deer is a bit foreign to North Americans, but people living in the UK will know that two small deer that were introduced from Asia, the Reeves’s muntjac and the Chinese water deer, actually possess sharp canine teeth.

It is thought that the ancestral deer was very similar to the so-called musk deer of Asia.  Musk deer have several features that true deer lack, and one of the most notable is their lack of antlers.  Musk deer have very well-developed canine teeth, and they look almost like saber-tooth cat crossed with a deer.

Musk deer are solitary animals, and if they meet, they use these long canine teeth on each other.

Just as it is the male true deer that typically have the antlers, it is the male musk deer who have the really impressive canine teeth.

The reason why it is thought that modern deer were much like musk deer is that many smaller species of deer in which the males possess impressive canine teeth.

The water deer of Asia has the long canine teeth, and neither sex has antlers. Water deer can form small groups, but they are less social than other true deer.

Reeves’s muntjac, which is native to temperate parts of Asia, has smaller canine teeth than a musk deer, and the bucks have antlers.  These antlers are quite small compared to other species of deer, and they use them primarily as a way of knocking their opponents off balance. After they knock their opponents off balance, they use their canine teeth on them.

Most modern deer have lost their canine teeth entirely. The antler has become the primary weapon.

But before deer had antlers, they had fangs.

And some still have them today.

The species we call reindeer or caribou (depending upon location and whether one is wild or domestic) probably could have had some use out of fangs.  Both sexes of caribou/reindeer possess antlers, which they use against each other.  It is thought that this species of arctic deer developed this trait– which is normally a trait of sexual dimorphism in other species– in order to give the females better tools to fight off other deer when the foraging gets tough in the winter.  Antlers take a lot of energy and nutrients to grow every year, so as weapons, they are pretty costly to the animal. Fangs really aren’t that costly, and they have them all the time.

Deer likely evolved super ornate antlers as a result of sexual selection.  The females are just more attracted to males with more ornate head weapons.

Caribou evolved from deer that had gone down this evolutionary road, so the trait of both sexes possessing antlers had to be built out of that lineage.

So female caribou have to devote energy and nutrients into growing antlers and into feeding their offspring. No other female deer has this problem.

That’s a major tax on any animal.

Ah, yes, we have another example of why intelligent design is crap.

And intelligent designer would have given caribou fangs.

But I don’t think Rudolph would be all that cute if he had the dentition of a saber-toothed cat!

Read Full Post »

People of the Reindeer

Source.

These are all people who live in the remote northern regions of the Russian Federation.

These people are reindeer pastoralists. However, they are not the only ones. Different groups in European Russia, Scandinavia, and Finland herd the antlered stock.

Different cultures in North America have also relied upon the reindeer, but these animals, which we call caribou, are all wild creatures.

 

Read Full Post »

Wolves hunting Santa’s Reindeer

Source

These wolves are hunting caribou, which are the wild reindeer of the North American Arctic and boreal forests.  It is the same species that exists in Eurasia.

Read Full Post »

What do steenbok have to do with Christmas?

I don’t know, but have a look this from Tetrapod Zoology.

Now, I can see where someone could get confused. How many people have seen the stop motion special Rudolph the Red-nosed Reindeer?

Here’s a clip in case you haven’t seen it:

Source.

The species that this cartoon was based upon was not the reindeer/caribou of northern Eurasia and North America. Because this special was made in the US, the species it was based upon was the white-tailed deer. In fact, if you watch the whole thing, the does don’t have antlers. In  real caribou/reindeer, the does do have antlers, an adaptation that helps them compete for scarce food resource during the worst part of the winter.

This makes some sense, though, if the average person in the US saw what reindeer/caribou actually look like, I seriously doubt that the film would have had any credibility. I mean they just aren’t that cute:

Thelon Caribou

Now, the young male reindeer in this special have little antlers, which look a lot like the steenbok’s horns. Unlike the reindeer/caribou, steenbok have actual horns, and only the males have them.

The word steenbok in Dutch refers to the Alpine Ibex, which is known as “Steinbock” in German. When the Dutch and German-speaking settlers came to Southern Africa, they called the little antelope they saw “steenbok,” and the name has lived on in the Afrikaans language and in English. (Similarly, the large antelope these settlers found was called an “Eland,” which is Dutch for elk/moose.”  In North America, we called the close relative of the red deer an elk. Yes, I know we got also got that one wrong, but at least what we call an elk is a deer!)

Steenbok live in Southern and Eastern Africa.  It is not exactly a species of the barren grounds of the High Arctic.

But maybe I have it wrong.

Maybe Santa Claus’s flying reindeer are actually flying steenbok, and they use their large ears as wings and soar just like the flying nun.

Source.

Read Full Post »

Entirely unrelated. Kven people milking reindeer in Western Finnmark in Norway.

Entirely unrelated. Kven people milking reindeer in Western Finnmark in Norway.

This is in Finland.

Reindeer are called caribou in North America. It’s the same species, and like the European version, the North American animal was once found much farther south than it is today.

It is a good thing that this eagles don’t come out at night, or we’d never get any Christmas presents. And Rudolph wouldn’t help much. He’d  just show the eagles where they were!

Read Full Post »

Canada lynx II

One of the most interesting biological stories takes place on the island of Newfoundland.  Before settlement, only Arctic hares could be found on Newfoundland. Its predators included the now extinct Newfoundland wolves and a very small population of Canada lynx.

Its population was small, mainly because Arctic hares use open habitats and they are always somewhat vulnerable to predation.

The small population of lynx that lived in Newfoundland were always at a bit of disadvantage. They are mostly adapted to eating snowshoe hares, which are creatures of  the dense forest. However, before the 1860’s, there were no snowshoe hares on Newfoundland.

The Canada lynx that lived on the island had to live like bobcats– eating what prey species availed themselves. Bobcats and Eurasian lynx are better at hunting deer species than the Canada lynx, but the Canada lynx on Newfoundland occasionally hunted caribou, especially the young of the year.

But because there were no easily captured snowshoe hares for the Canada lynx to eat, their numbers remained quite small. The Canada lynx doesn’t do well as a bobcat.

In the 1860’s, the government of Newfoundland discovered it had a problem. Lots of people were going hungry. The forests and sea were not producing enough to feed them.

To rectify this problem, the Newfoundland government introduced the snowshoe hare, which is staple in the diet of many rural residents of the mainland. The hares fed the people, and they adapted well to Newfoundland’s environment.

And they spread. In the early 1900’s, there were tons of them on the island. They soon reached what ecologists call the “carrying capacity” and then many of them starved.

Then something else happened.

Arctic hares began to disappear, and the caribou numbers began to drop.

What caused the numbers of those species to drop?

Well, it has something to do with the Canada lynx.

What?

Well, as I said before, the Canada lynx is a snowshoe hare specialist. On the mainland, its population is directly linked to snowshoe hare populations. It lives almost exclusively on them, and it is very well adapted to hunting them.

When the  population of snowshoe hares began to take off in Newfoundland, the native Canada lynx population could stop living like bobcats. They could return to their ancestral habits of hunting the snowshoes, the species they evolved to eat.

Things were fine until the snowshoe hares reached their carrying capacity and their population dropped off.

Then, the larger population of Canada lynx that had developed from eating those large number of snowshoe hares had to find something else to eat.

They slaughtered the Arctic hares, even though Arctic hares are much harder for the Canada lynx to hunt. With so many Canada lynx in Newfoundland looking for food, the poor Arctic hares had no respite from the predation. The predation was so intense that Arctic hares can be found only in remote areas the northern part of the island, where one cannot find Canada lynx or snowshoe hares.

On the mainland, Canada lynx, snowshoe hares, and Arctic hares are not found in the same spots. Arctic hares are always found to the north of prime Canada lynx and snowshoe hare habitat. It is likely that Canada lynx are the main reason why Arctic hares have a rather clearly demarcated southern limit to their range. They simply cannot live where Canada lynx and snowshoe hares do, because the Canada lynx will eat the Arctic hares when the snowshoe hares have their population crash.

Yes, snowshoe hares have a ten year cycle in which the population hits its carry capacity within ten years and then has a massive die off. Then it rebuilds after that die off until it hits its carry capacity ten years later. The Canada lynx is at the mercy of these ten year cycles. And so, it seems, is the Arctic hare.

The introduction of the snowshoe hare in Newfoundland had been a major disaster for the Arctic hare, even though the two species do not necessarily conflict with each other. They don’t even live in the same habitats, with Arctic hares preferring the open tundra and snowshoes preferring the forest. It is the rather strong predator-prey relationship that exists between the snowshoe hares and the Canada lynx that ultimately affected the Arctic hare.

Now, that is only part of the story.

Why did the caribou drop off?

Well, it is a very similar story.

When the Canada lynx population exploded with the introduced snowshoe hares, they generally left the moose and caribou alone. Canada lynx will eat snowshoe hares before they’ll touch any species of deer.

When the snowshoe hare population collapsed, the caribou and moose population began to suffer almost as badly as the Arctic hares.

The caribou population collapsed through the 1950s until there were just a few hundred caribou on the island.

It turned out that many of these caribou were dying as calves from a bacterial infection. Large numbers of calves were found dead. They had strange puss-filled marks on their throats, which were cultured and found to have the Pasturella multocida bacteria in those puss-filled marks. It was this bacteria that was killing them.

The caribou of Newfoundland prefer to calve in low-lying swampy areas on the island. They try to keep their calves out of the elements so they do not succumb to illnesses or the elements.

So why were they getting this bacterial infection? And what about the strange marks on the caribou calves’ throats?

Well, remember the earlier story about the Canada lynx and the snowshoe hares in Newfoundland?

It turns out that the Canada lynx were not only preying on Arctic hares when the snowshoe population crashed. They were also preying caribou calves. However, as I said before, Canada lynx are pikers when it comes to hunting any species of deer.

They often made a mess of it.

As you are aware, cats often kill by a bite to the throat. Canada lynx kill biting the throats of their prey. However, when they tried to kill caribou calves, they really didn’t do too well. They really don’t have the teeth of a big cat to really suffocate a large prey species like a young caribou.  When they would have a young caribou on the ground biting its throat, the mother caribou would have time to run back and drive the lynx off its calf.

With that many lynx making failed attempts to kill young caribou, it didn’t take that long for lots of calves to get infected with nasty bacteria. And thus, they died.

Now, the discovery that Canada lynx were causing Arctic hare and caribou populations to drop was a major revelation in population ecology. The biologist who made this discovery was A.T. Bergerud.

Bergerud’s discoveries were a major afront to the accepted theory in wildlife management at the time.  Before Bergerud, the accepted theory was that of Paul Errington. Errington’s theory is the classical predator-prey relationship. Prey species produce many offspring, usually far more than the habitat can handle, but these prey species are kept in check because they are eaten by the predators. The ones the predators catch are called the “doomed surplus.” Predators play a vital role keeping these prey species at healthy numbers.  Because natural predators take the animals that are part of this doomed surplus, natural predators do not make prey species go extinct or make their populations drop precipitously.

Bergerud’s theory is quite different from that. It suggest that there are conditions in which predators actually can make a population drop really quickly.

I don’t think that it entirely negates the classical wildlife management theory on predator-prey relationships. However, there are exceptions to every rule, and the Canada lynx and snowshoe hare are pretty exceptional species. Not very many predators are so closely linked with a single prey species. It is also rather unusual to find a prey species with such clearly defined cycle to its population dynamics as the snowshoe hare.

And Newfoundland is a pretty strange place. It is an island that never had snowshoe hares on it. When prey species are introduced to an environment where they don’t have many predators, they will reproduce at an astounding rate. The doomed surplus doesn’t become doomed, and the population explodes until the ecosystem can handle no more. The small population of Canada lynx had been eking out an existence as a generalist predator until the snowshoe hares appeared like manna from heaven.

Yes, it is an unusual situation, but it proves that exceptions exist to every rule. And that’s why predators sometimes need to be managed to protect the prey species.

Read Full Post »

%d bloggers like this: