The Making of Planet Earth: The Polar Bear

First of all, don't forget to scroll down and look at today's official post, about the three-toed sloth! 

I almost forgot to tell you all about another very interesting video clip about the polar bear, from "The Making of Planet Earth."  The clip below, narrated by David Attenborough, features the challenges that the main cameraman Doug Allan, aided by his field assistant Jason Roberts, came up against when it came to filming the polar bears in Norway.  Not only is the video quite interesting, it gets amusing towards the end, as well!

Filming the Polar Bears

Below is a picture of cameraman Doug Allan.  In the picture below, he is staked out, attempting to film the snow leopard, one of my absolute favorite animals.  This elusive cat proved quite difficult to film, and, hopefully, sometime in the next few weeks I can talk about the difficulties the crew of Planet Earth encountered when it came to filming the snow leopard in the wild.

Animal Spotlight: The Sloth

Today's "Animal Spotlight" is the arboreal South American three-toed sloth (Bradypus variegatus).  The three-toed sloth holds the record for the world's slowest mammal: in fact, it is so slow, that algae grows on its fur, giving it a greenish color.  The algae helps to camouflage the slow animal in the treetops of its rainforest home.  In the case that its camouflage fails it, then it will resort to taking a stab at its attacker with its incredibly large claws.  Definitely not something that you want to take a hit from.

After perusing a few sources, I have come up with a list of the top 10 sleepiest animals, as you can see below.  The numbers are all number of hours spent sleeping a day. 

1. Koala:            20-22
2. Sloth:             20
3. Armadillo:       19
4. Opossum:       19
5. Lemurs:          16
6. Owl Monkey:  17
7. Lion:              14-16
8. Hamster:        14
9. Squirrel:         13-14
10. House Cat:     11-12 

 HERE is a link to an earlier post about the koala, and why it is so sleepy.  The sloth apparently is so incredibly sleepy simply due to the fact that its leaves are so poor in nutrients, much like the predicament the koala finds itself in.

Two other sloth facts struck me as pretty interesting.  The first one is the fact that, due to a few extra neck vertebrae, the sloth can turn its head 270 degrees, as you can see in the picture below.

The second interesting fact is that, despite the poor ability of the sloth to walk on the ground due to weak hind legs, they are actually surprisingly adept swimmers, as you can see in both of the videos below.

A Sloth Walking

A Sloth Swimming


According to the website of National Geographic, the three-toed sloth is labeled as "Endangered" by the IUCN.  Sloths live in Central and South America, and the three-toed sloth specifically inhabits the countries of Venezuela, Guyana, Suriname, French Guyana, and Brazil.

Finally, to learn a little bit more about the sloth, click on the link below.  The video is a short clip narrated by David Attenborough, and is also quite amusing.  Enjoy!

Saying "Boo!" To A Sloth

Animal Spotlight: The Polar Bear

The polar bear (Ursus maritimus) is the world's largest extant, terrestrial carnivore, with males growing up to 1,500 pounds.  Like many animals that spend a good amount of time in the water, their feet are partially webbed to aid in swimming.  Although the fur of the polar bear is white, to help it blend into the ice and snow when it is hunting seals, its skin underneath is black, to aid in heat absorption.

In the picture above, it certainly looks like the polar bear is just enjoying itself, and having a good time.  While both of these may be true, the polar bear is actually cleaning its fur, presumably after a kill, given the blood-stained snow off in the left of the picture.  Below the picture is a link to a video clip from BBC's "Planet Earth," narrated by one of my personal heroes, David Attenborough.  In the video, make sure to watch for the fur cleaning.

This is the link to the Planet Earth link: https://www.youtube.com/watch?v=OwZH_aT0FGI

The polar bear, due to its immense size and lack of natural predators, fears nothing, humans included.  This, coupled with a natural, and insatiable, curiosity, often brings bears and humans into contact.  The video clip below is from another BBC show, called "Polar Bear: Spy on the Ice."  I first saw this show when we were in South Carolina this summer, and found it really interesting!  This clip is one of my favorite parts from it.

Polar Bears Attacking Spy Cameras:  http://www.youtube.com/watch?v=DvduCPXO_FE

Finally, we have another interesting YouTube video that I discovered today.  Watch and enjoy!

https://www.youtube.com/watch?v=JE-Nyt4Bmi8

The polar bear's range covers five different countries: Russia, Denmark owned Greenland, Norway owned Svalbard, Alaska, and Canada.

We Interrupt Our Previously Scheduled Programming: Robert T. Bakker

So today I went in for an interview for a volunteer position at the Morrison Natural History Museum (you should check it out, it's pretty cool!).  I went in, and I met Robert Bakker.  He is pretty much like the Michael Phelps of paleontology.  He is really, really cool.  He and John Ostrom were pretty much the catalysts of the so-called "Dinosaur Renaissance," where the ideas of dinosaurs being cold-blooded, sluggish, stupid and slow were turned on their heads.  So that was pretty exciting.  Below is the link to his page on Wikipedia.  Very exciting stuff!

http://en.wikipedia.org/wiki/Robert_T._Bakker

We will get back to the polar bears later in the day, but I had to talk about this first!

Evergreen on Dwellable

What REALLY Killed the Dinosaurs?

Today, almost all paleontologists believe in one of two scenarios that brought upon the downfall of the dinosaurs; the Silver Bullet Hypothesis, and the Blitzkrieg Hypothesis.  Proponents of the Silver Bullet Hypothesis consider the asteroid that hit Mexico 65.5 MYA to be the cause of the dinosaurs extinction, while fans of the Blitzkrieg Hypothesis believe that the asteroid worked in concert with other factors, like a number of extraordinarily large volcanic impacts and receding sea levels.  Although both of these hypotheses hold great weight, and stand up well to investigation, I find myself more in the Silver Bullet camp.  (If you are unsure, check out this video: http://www.youtube.com/watch?v=5gqq2rgOmi8 .  It's a bit long, but you can skip parts of it and still get the gist.  I was simply blown away after watching it, and landed smack-dab in the center of the Silver Bullet camp.)

However, this post is not to talk about the merits of the generally accepted dinosaur-death hypotheses; just like the post regarding the oddly named animals (http://thenaturalworld1.blogspot.com/2012/07/masiakasaurus-knopfleri-and-other.html), Scott Sampson's book Dinosaur Odyssey had another especially interesting tale, a tale about the many different hypotheses (over one hundred in all!) about how the dinosaurs died from over the years.  Here are some of the more interesting ones, quoted from Scott Sampson's book:

1.   Disease
2.   Slipped Vertebral Discs:  Because dinosaurs were so big
3.   Loss of Interest in Sex
4.   Poisonous Plants 1:  The consumption of these plants led to a deadly diarrhea amongst the dinosaurs
5.   Poisonous Plants 2:  The consumption of these plants led to a deadly constipation amongst the dinosaurs
6.   Fungal Invasions
7.   Climatic Change 1:  Global Warming
8.   Climatic Change 2:  Global Cooling
9.   Cosmic Radiation From a Supernova
10.  Egg-Eating Mammals
11.  Sunspots
12.  Nasty Aliens
13.  Not Enough Room on Noah's Ark
14.  The Racial Senility Hypothesis:  Dinosaurs, as a group, were young and restless when they first appeared in the Late Triassic Period.  During the Early Jurassic, the dinosaurs experienced "adolescence," as they expanded "in both form and diversity."  When they reached the Late Jurassic and Early Cretaceous, the dinosaurs had "reached their evolutionary peak;" they were middle-aged, and had nowhere to go but down.  Thus, in the Late Cretaceous Period, when the dinosaurs like Triceratops, Parasaurolophus, and Pachycephalosaurus grew interesting crests, frills and the like, these were "the result of hormones gone wild and certainly symbolic of a group on its way out."

Obviously, some of these solutions are more interesting than others, but all of them are, at this point in the study of dinosaurs, outdated.  But who knows: perhaps, someday soon, someone will discover proof that it was aliens, and not an asteroid, that ultimately did-in the dinos.

The Fox's Animal Magnetism

For a while now, it has been thought that birds could see the magnetic field, in order to help them migrate.  It has been hypothesized that, when they are facing north, they can see a little blurry patch at the bottom of their eye.  If they are facing east or west, then they can't see the patch, so they know where to put the patch in their field of vision to get where they want to go.  Recent research by a Czech team of scientists seems to indicate that the red fox can also use the magnetic field, but for a different purpose: hunting.

The red fox (Vulpes vulpes) ("Least Concern" by the IUCN) has the largest geographical distribution of any member of the Carnivora, with habitat on all of the continents except for South America and Antarctica.  In North America, it inhabits the United States and Canada, in Europe and Asia it lives almost everywhere, and in Africa it lives in Morocco, Algeria, Tunisia, Egypt, Sudan, and Libya.  Not only does it possesses the range shown in the map below, it has been introduced to Australia, where, like the Dingo, it poses a threat to native species.

The red fox hunts by leaping up into the air, and coming down right on top of its prey, literally (for the prey, at least) appearing out of nowhere.  But how to pinpoint its jump?  The answer lies in the magnetic field, which is visible to the foxes.  But how does this work?  Out of all of the explanations set forth by various journals and such, I thought the explanation from Nature was easiest to understand.  Here's what they have to say:

"Think of a laser pointer attached to you that always points slightly downwards in the same direction. Now think of some object on the ground. If you walk towards the object until the laser spot is on top of it you know that object is a set distance away."

Generally, it was thought that foxes would pinpoint their location solely using their very acute sense of hearing.  But then the Czech team found that, when the red fox was leaping in a northerly direction, 74% of the attacks were successful, while the leaping attacks in other directions had the success rate of a mere 18%.  That's a very big difference, and seems to point to the magnetic field theory.

A picture of the red fox outside of the house that our friends the Beckleys rented in Breckenridge one summer.  Awesome place to stay, especially if you are looking to escape the summer heat!  Photo Credit: Julie Neher

East Breckenridge on Dwellable

What Is It? The Weekly Challenge #3 Answer

Today's animal was easier for many of you, and we had a number of good guesses!  We had a few close guesses (like the American Kestrel, another North American bird of prey, but we had one totally right answer.  This weeks winner is Julie N., who guessed the Peregrine Falcon!

Peregrine Falcon

 The Peregrine Falcon is one of my favorite birds, mainly because of how it hunts.  It dives at medium-sized birds from up to 3,000 feet in the air, and often dives towards the birds with the sun at its back; that way, its prey has a difficult time of seeing them through the sun's glare.  In its dive, speeds of 175 - 200 mph have been recorded, placing it at the terminal velocity able to be achieved by the bird.  Some people have reported that the peregrine can exceed terminal velocity but, despite being taken in by this theory for a time, I believe that this not, in fact, true.  (I am not that into the math or physics, but I believe it might even be impossible, but I'm sure some of you know that better than me!)  Click on the link below to learn a little more, and to see the bird in action!

http://www.youtube.com/watch?v=cKqt05iR9WI&feature=player_embedded#!

Although their population numbers suffered tremendous, pesticide-induced blows during the 20th century, they have made quite a comeback throughout the United States.  However, it was a close call.  Use of pesticides like DDT (commonly known as DEET, used to be common in mosquito repellent before its negative impacts on the environment became fully known) caused the Peregrine Falcon's eggshells to become weak, and they were easily broken.  The result of this was very few baby falcons surviving to breed themselves.  In fact, at one point it got so bad that the Peregrine Falcon was listed as "Endangered" by the IUCN in the 1950's through the 1970's.  It became extirpated, or locally extinct, in both Belgium and the eastern United States.  However, now it is labeled as "Least Concern;" an amazing comeback, for an amazing bird.

This picture of the Peregrine Falcon was taken by me, last week at the Reptile Day at Dinosaur Ridge, near Golden.  My friend Masaki Kleinkopf and I went and were able to see a few pretty cool things, the Peregrine Falcon being just one of them.  I highly recommend going to check out the Ridge, as well as the museum they have there, it is really quire interesting!

Don't forget to check in later in the day for this week's challenge!