Top Ten Most Interesting Arboreal Mammals (Part 2)

Welcome to Part 2 of the Top Ten Most Interesting Arboreal Mammals in honor of the birthday of Charlie Bowers!  FYI, for those of you who don't know, arboreal means an animal that lives in the trees!  For Part 1 of this duology, click HERE.

5.  Fossa - The fossa has one of the most interesting and amusing scientific names: Cryptoprocta ferox.  Any guesses as to what that means?  If you guessed "Fierce Hidden-Anus," then you are spot-on!  Native to Madagascar (and, in fact, the largest carnivore of the "Lost Continent"), this cat-like creature is not actually a cat.  Instead, it is closely related to the civets and the genets, like the binturong.  To see a video of how incredibly acrobatic the fossa is, click HERE. 

4.  Cats - We talk about cats a LOT on this blog, and we are going to talk about them again today!  Quite simply put, cats are quite possibly the most acrobatic group of carnivores in the world.  Many of them are acrobatic on the ground (like the caracal, serval, and cheetah), while others are acrobatic in the trees.  Some of these are larger cats, like the leopard and the jaguar.  Others are smaller cats, like the ocelot and the margay, the latter of which can rotate its ankles around 180 degrees in order to climb down the trunks of trees head first!

3.  Ringtail/Cacomistle -  A member of the raccoon family Procyonidae like their relatives the coatis and olingos, the ringtail and the cacomistle are pretty obscure animals.  The ringtail actually lives as far north as southern Oregon, and throughout the southwestern United States, as well as in Mexico.  The range of the cacomistle actually overlaps that of the ringtail in Mexico, but the cacomistle also lives as far south as Panama.  They are both omnivorous, and insects, fruits, arthropods, and small vertebrates are important components of their diets.  They are also both listed as "Least Concern" by the IUCN.

2.  Tamandua -  Like all anteaters, the tree anteaters, such as the tamandua (pictured above) have very strong, large, and powerful claws, made to access the nests of ants.  These claws also happen to be perfect for climbing.  It's tail, like many other arboreal creatures, has evolved to be prehensile, which is an enormous benefit when climbing in the trees.  This fifth limb, if you will, is especially important when the tamandua has to tear into the bark of trees to expose the tasty insect treats within, helping to keep the tamandua from falling from the trees.  The tail is actually powerful enough to support the weight of the entire animal!  You don't often think of anteaters climbing around in the trees, which is why I think that the tree anteaters are excellent candidates for our number two spot on the list.  To see a video of the tamandua in action, albeit in Russian or something (it doesn't really matter, just watch without audio or something, but make sure to watch from 1:00 onwards) click HERE.

1.  Tree Kangaroos - Sometimes, nothing is quite as funny as a kangaroo.  But imagine a smallish kangaroo hopping around in the trees, a hundred feet or more above the ground.  Believe it or not, such a thing exists!  Having evolved from the rock-wallabies (who are in turn thought to have evolved from the pademelons), the tree kangaroos are pretty awesome creatures!  Reportedly pretty clumsy in the trees, it is hypothesized that, if there were any significant predators in the area (like many of the carnivores that we have been talking about in these two posts), the tree kangaroo would have either have had to evolve, or they would have been hunted into extinction by these predators.  Since it is so clumsy, and it spends so much of its time between 70 and 100 feet above the rainforest floor, the tree kangaroo has adapted to large and significant falls from high in the sky.  They can fall around 60 or 70 feet with no physical harm!  Don't believe me?  Once you click the video link HERE to learn more, go ahead to about 5:10 if you want the skinny.  You will be able to enjoy a tree kangaroo falling!  And don't worry, it won't be hurt: just check out the video!

The Ancestral Australian Aborigines As a Possible Cause for the Extinction of Australia's Pleistocene Marsupial Megafauna

A few weeks ago, in my Anthropology class, we had to do a cultural profile of one culture group of humans.  I chose the Australian Aborigines and, having just finished Tim Flannery's excellent book "Chasing Kangaroos," this whole concept of the Ancestral Aborigines being the possible cause of the extinction of Australia's Pleistocene megafauna was still quite fresh in my mind, so I included it in the paper.  I thought it was pretty interesting, and so I have decided to share it with ya'll, too, with a few brief modifications to make it more Blog friendly!  Hope you enjoy, and if you want a more comprehensive look at the topic, I highly recommend "Chasing Kangaroos!"

Interestingly, paleontologists today are using the Australian Aborigines to help them figure out when Australia's Pleistocene megafauna went extinct.  While today, there are no native animals larger than the red kangaroo, Pleistocene Australia was a very different place, as was the rest of the world.  The Pleistocene Epoch was the time of the Ice Age megafauna.  With the exception of Africa and south-east Asia, in most places nowadays, the Pleistocene megafauna is extinct, but back then, the megafauna were a world-wide phenomenon.  In Eurasia, there were the giant mammoths and rhinoceroses, the cave lions and hyenas, the Irish elk, and the giant polar bear.  In North America, there were the mammoths and mastodons, the short-faced bear, the giant bison, the dire wolf, the giant beavers, and the saber-toothed cats.  In South America, there were the giant ground sloths, the armored glyptodonts, and many large relatives of elephants.  

Australia also had its fair share of Pleistocene megafauna, with marsupial lions, the giant short-faced kangaroos, the hippo-sized wombat Diprotodon, and echidnas that were the size of sheep.  There are two main hypothesis when it comes to what caused the extinction of all these animals: climate change, or hunting by early human arrivals on Australia, the first Aborigines.  No one could figure out whether it really was the Aborigines that had hunted the megafauna to extinction, though, because no one could figure out the date that the megafauna had gone extinct, nor could they figure out the date that humans first arrived on Australia.  Some people believed that the megafauna survived until around 6,000 years ago, while others believed that they went extinct a great many years prior.  The same difficulties confronted those scientists attempting to determine when humans first arrived.  The sediments of Australia are notoriously hard to date, and since the animals of Australia are so unique (especially following the extinction of the dinosaurs), scientists were unable to correlate their data with other places around the world.[1] 

As more scientific discoveries were made, a new method of dating rocks was discovered, called optically stimulated luminescence (or OSL for short).  Using OSL, paleontologists were successfully able to date many different specimens of the various marsupial Pleistocene megafauna, and found that, while many of them approached the 46,000 years ago mark, none of them passed it.  Many different specimens were used from all across Australia, but they all said the same thing: 46 was the answer. 

Meanwhile, with the new OSL tool in their bag, other scientists headed off to sites of known human habitation to attempt to date them as well, and these efforts proved to be successful.  One of the main places that they dated was a place known as Devil’s Lair, a known area of ancient Aboriginal inhabitance.  What was especially important about Devil’s Lair was that there was sediment present for the last 63,000 years, meaning that instead of just a snapshot of time, the scientists had an uninterrupted sequence of time to figure out when humans started living there.  As the scientists dated the sediments with the first signs of human inhabitance, they came up with the magic number: 46,000.  Other sites came up with the same number too, including Lake Mungo, the oldest human burial known from Australia.  At Lake Mungo, the dates were a bit less precise, ranging from between 45,000 and 47,000 years ago, but the data still seems to point in the same direction.  The ancestral Aborigines arrived on the continent at around the same time that Australia’s Pleistocene megafauna went extinct.  With this new dating technique, scientists were also able to determine that there was no significant climate change for many thousands of years on either side of the 46,000 mark, effectively ruling out that hypothesis.  So it seems that, for a time, the people who believe themselves as part of the land and the natural world around them actually destroyed a significant part of it.

[1] For example, paleontologists studying dinosaurs of the Late Jurassic Morrison Formation here in Colorado are able to look at closely related dinosaurs in other parts of the world like the UK and southern Africa (keep in mind that the continents were all together in one big landmass back then.)  That way, if the paleontologists are unable to determine the dates of, say, the Tendaguru Formation in Tanzania, they can look to the studies done on the rocks of the Morrison Formation for an accurate estimation.  This is a luxury that paleontologists, archaeologists and other scientists working in Australia simply do not have. 

Mildura on Dwellable

23-Fact Tuesdays: Polar Bear Celebrations, Eccentric Artists, and Unicorn Horns!

Welcome to our third "23-Fact Tuesday" which are never on Tuesdays.  I believe that this one is actually closer to a Tuesday than we ever have been before, however, so that's got to count for something!  I'd also like to thank Mona Kamath for her help on this post!  Enjoy!

1.  Despite the fact that polar bears are generally solitary, they gather annually in places like the city of Churchill in Manitoba, Canada, where they congregate together prior to the freezing of the sea ice.  When they gather in groups like this, the group is called a "Celebration." 

2.  The eccentric and incredibly odd (though undeniably gifted) artist Salvador Dalí had a pet ocelot named Babou.  He also had a pretty righteous mustache, if I do say so myself.

3.  In 1663, the German scientist Otto von Guericke "reconstructed" the mythical unicorn using the fossilized bones of a mammoth, a woolly rhinoceros, and the horn of a narwhal.  This reconstruction managed to legitimately fool some people, including Gottfriend Wilhelm Leibniz, the famous German philosopher and mathematician, who reportedly was dubious about the existence of the unicorn prior to this "reconstruction," but was convinced by Guericke's "fossil."  

4.  From wing tip to wing tip, Hatzegopteryx measured an astonishing 46 feet!

5.  Gasosaurus, a dinosaur that was described in the year 1985, was named "Gas-Lizard" because it was discovered by a Chinese gas-mining company.

6.  In order to hover and move in any direction, the hummingbird, often nick-named "nature's helicopter" moves its wings in a figure-eight pattern, as opposed to the up-and-down motion typical of other birds.

7.  Cotylorhynchus, one of the largest pelycosaurs, is quite possibly the funniest-looking extinct animal I have ever, ever seen.  It was also discovered by my 9th grade Language Arts teacher's great great uncle, J. Willis Stovall, a famous paleontologist. 

8.  One of the elephants at the Cheyenne Mountain Zoo is named Kimba, which means "Poop" (I used the nicer term for what the word actually means there) or "Corpse" in Swahili.

9.  Speaking of poop, fossil poop is known as a "coprolite."

10.  The acrobatic margay can rotate its ankles 180 degrees, which allows it to descend tree trunks head-first and hold on to branches with either their front or back paws.

11.  The white-tailed deer is named for the white patch on its rump and tail, while the mule deer is named for the fact that its face resembles that of a mules.

12.  About a third of the extant mammalian species are rodents.

13.  Hopping, the method of locomotion preferred by the kangaroos, is actually much more efficient than walking.  Of course, this is only the case if you have evolved in that fashion.  It wouldn't just be more energy efficient if we started hopping around everywhere.  

14.  Although you often hear people mention the "saber-toothed tigers," this is actually a bit of a misnomer, due to the fact that the saber-toothed cats to which they are referring to are not actually tigers, and are simply just cats.  

15.  The sweat of the Hippopotamus, is red or pink, leading people to aptly refer to it as "blood-sweat."

16.  Despite the fact that the polar bear has white fur, the color of its skin is the complete opposite: jet-black.  Talk about Yin/Yang right there.

17.  Island dwarfism is suspected to have occurred in one of our human relatives, Homo floresiensis, who inhabited the island of Flores in Indonesia up until around 12,000 years ago.  The nick-name for this ancient human is "The Hobbit." 

18.  The word "Mona" means "monkey" in Spanish.  Sure would suck if that was your name now wouldn't it!

19.  In Hindu culture, owls are a sign of bad luck.  That double sucks if you are Hindi and terrified of birds.

20.  Speaking of owls, due to the fact that they have binocular, or stereoscopic, vision (unlike other birds of prey, who have an eye on each side of its head), they have evolved the ability to turn their heads around 270 degrees in either direction.  Must be tough for them to crack their necks.

21.  Despite the fact that the creature in the picture below looks like a raccoon, it is not: that, my friends, is the raccoon dog!

22.  The tusks of the elephants are actually greatly elongated incisor teeth.  For reference, tap your front two teeth on the top or bottom of your mouth, it doesn't matter which, they are the same.  Those are your incisor teeth, you have two on each side of your mouth, eight all together.  

23.  In the narwhal, however, the tusk is their canine teeth, which (at least in our mouths) are the teeth right next to our incisors, towards the outside of our mouths. 

Introducing....the Primos Truth Cam; The Ostriches of Longmont, Colorado; And Engagement Congratulations!

The most recent addition to my proverbial arsenal is the Primos Truth Cam!  (For those of you who are wondering, my arsenal includes my camera, Denali; my backpack, Rocky; my First Aid kit, Reginauld; and my rock hammer.  You don't name your rock hammer.)  Equipped with both video and photo capabilities for both day and night, I have set it up in a place where I know there to be red foxes!  I can't promise anything of course, but I have sprinkled an alluring amount of fox urine near the cam, so, with any luck, tonight we will be successful in our endeavors!  I will let ya'll know what happens tomorrow!

Speaking of names, I would be much obliged if you all could help me think of a fantastic name for my camera!  THANKS.

Another pretty exciting event occurred yesterday!  During our first period Anthropology class (a hoot and a half, fyi), I was talking to my group members about the time that my father and I were driving down Broadway, in between Boulder and Superior.  Off to the right was a lot of farmland, and, at one point, I was almost positive that I had seen kangaroos!  I told my dad to turn back, and, once we got home (which was pretty much the very first place that we could turn around), we turned around, and we were back within five minutes.  I couldn't remember exactly where I had thought that I had seen them, but (unsurprisingly) there were no kangaroos.  To this day, every time we drive by that area, both my dad and I turn to look.  To this day, we have not seen the phantom kangaroos.

Anyways, I was telling my Anthro friends about this event, and one of them, a friend of mine named Grace Albers, said that she had seen ostriches in Longmont, not twenty minutes from my house!  Incredibly excited, I told another friend of mine, Claire Chen, about it, and we headed over there during the next class period.  (Don't you worry, I wasn't ditching, but our school has Wednesday and Thursday block, where we only have half of our classes, but they are each twice as long.)  AND GUESS WHAT WE SAW.

OSTRICHES.

OSTRICHES

THAT'S RIGHT.

THAT'S RIGHT. 

 OSTRICHES.

OSTRICHES

WHAT THE HECK.  Apparently there is an animal hospital thing, and at the place they have two ostriches!  Crazy, huh!

An OSTRICH  preening!

And finally, I would like to congratulate my cousin, Alexa Neher, on getting engaged to her boyfriend Christopher Koreerat!  Congratulations, you two!

Propleopus, the Carnivorous Kangaroo

Imagine you are on a safari to the Masai Mara National Reserve in Kenya.  If you timed your visit right, then the Mara is inundated with wildebeest and zebra, as well as numerous other herbivores.  You will probably see a number of carnivores as well: cheetahs, leopards, lions, and especially hyenas.  What you probably don’t realize is that most places aren’t like this.  The Masai Mara has one of the highest predator populations seen in Africa, due in large to the great number of prey animals available for a meal.  Regardless, you are forced to acknowledge that there are a great many more prey animals than there are animals to prey upon them. 

                This is known as the predator/prey ratio, and it can be seen all over the world, and can also be seen in the past.  While hundreds, sometimes thousands, of fossils of a single herbivorous dinosaur can be discovered, it is far more rare to unearth the remains of a predatory dinosaur.  But why is there this unbalance between predators and their prey?  Well, let’s take a look at a continuous, cyclical event that takes place in a period of 9.6 years in the wilderness of Canada, that should be able to shed some light on the situation.

                At the beginning of the almost-ten year cycle, we see a sharp increase in the number of hares.  When food is plentiful, these hares often produce two to three litters of around 12 leverets (baby hare) each.  After their numbers reach their limit, their population density reaches around eight hare per football field.  At this time, the hares have eaten all of the edible material they can reach.  Not only are they out of food, but the plants that they feed upon begin to create bitter chemicals in their leaves and edible parts, that keep the hare from digesting the plant material very efficiently. 

                While the hare population is flourishing so, the hare’s predators find an especially easy time of it.  Owls, wolves, and foxes all flourish, but one predator does particularly well: the Canadian lynx.  Hares consist between 40 and 85 percent of the average lynx’s diet, and they generally kill two hares every three days.  With such an explosion in hare numbers, all of these predators flourish, successfully raising more owlets, kits, and cubs.  However, shortly after the plants begin to release the anti-digestion chemicals, the hare populations tank.  With not enough food, many of the animals die off.  Then, a year or two after the hare die-off, the lynx also experiences a massive fall in numbers.  With the lynx no longer over hunting the hare, and the predator/prey ratio returned to normal, the hare starts the cycle all over again. 

                While this cycle seems to be a healthy part of the Canadian ecosystem, in other places, a rapid rise in the number of predators or prey could be disastrous.  Therefore, nature has made it so that, in a healthy ecosystem, the prey animals vastly outnumber the predatory animals.  But how does all of this tie into kangaroos?  We will get back to that in a minute.  First, let’s take a look at an extinct, 26,000 year old relative of today’s rat kangaroo. 

                First described by Australian zoologist Charles De Vis around the turn of the century, the holotype of Propleopus at first remained unique.  It wasn’t until the year 1967 that more remains belonging to the genus Propleopus appeared.  More was discovered in the following years, but very few remains have been discovered even to this day.  With millions of fossilized mammalian bones discovered in Australia, Propleopus are “known from teeth and jaws attributable to less than 20 individuals.” 

                There are multiple reasons why an animal does not appear with a great amount of frequency in the fossil record.  Perhaps it is because the animal was small; smaller bones are much more delicate, and therefore less likely to survive the fossilization process.  (They are also a lot smaller, and therefore usually harder to find then, say the humerus of an Brachiosaurus!)  Perhaps the animal lived in an environment where fossilization is unlikely.  For example, in millions of years, when intelligent life again evolves on this planet, or we are visited by intelligent life from elsewhere in the galaxy, they would find very little or no evidence of mountainous animals, like bighorn sheep or the snow leopard.  This is because mountains are in a constant state of geologic flux.  At times they are being pushed up; but even when they are rising, they are already eroding.  Given enough time, entire mountain ranges can disappear, or almost disappear, like in the Australian Outback.  Sometimes, it is because paleontologists are simply looking in the wrong places, and there are treasure troves of these animals just waiting to be discovered elsewhere.  It could also be because the rocks where the animal was deposited simply don’t exist anymore, something that is called an unconformity in geologist’s terms.  Maybe the animal was just not very successful, and went extinct after only a short amount of time.  The fossilized animal could also represent a transitional fossil, so creatures with those characteristics would have only been around for a few thousand years.  Or, of course, it could be because the animal was a predator, and there were fewer individuals to begin with.

                Now you are probably thinking that this is quite a leap.  Just because this kangaroo didn’t appear all that often in the fossil record doesn’t necessarily mean that it was carnivorous.  And you are right, as if this was the only evidence of Propleopus being a carnivorous kangaroo, I would be laughed right out of the Neolithic Age: and they, at best, had only a very, very primitive form of language, and probably would, at best, barely understand what I was saying.  However, there is more evidence in favor of a carnivorous Propleopus.  As I am fond of saying, “the teeth tell the tale.” 

                Studies of the dentition of Propleopus show a close resemblance to small, extant insectivores or omnivores, i.e. the mountain pygmy possum and the musky rat kangaroo.  Where the teeth of Propleopus differ from the mountain pygmy possum and the musky rat kangaroo, however, the differences “could be interpreted as adaptations to meat-eating.”  To sum up, the incisors are short, stout, and appear great for stabbing, the premolars are strongly serrated, which is perfect for tearing into very tough stuff (perhaps tendon), and the molars are greatly reduced in size, as sometimes seen in the genus Wakaleo, one of the genera of marsupial lion, like Thylacoleo.  Furthermore, the molars, although reduced in size, share similar features to the largest extant marsupial carnivore today, the Tasmanian devil.  These features in the Tasmanian devil serve to keep bone splinters from penetrating the gums, and clearly would not be needed to serve that purpose in an herbivore. 

                The most revealing tale of the teeth can only be revealed by a microscope.  Studies have shown that, when you compare the microscopic wear patterns on the teeth of a herbivore and a carnivore, you can see obvious, and distinguishable, differences.  The teeth tell the tale of the diet of an animal, and help to show us what Propleopus might have eaten.  When compared with the wear patterns of closely related herbivores, like the musky rat kangaroo, and marsupial and placental carnivores, like the thylacine, Thylacoleo, and dogs, the wear patterns seen on Propleopus resembles that of the carnivores more so than that of the herbivores. 

                So was Propleopus a carnivore, or a herbivore, or both?  One hypothesis that has been put forward is that Propleopus was situated in a similar ecological niche as the modern day African baboon, eating whatever came it way, be it plants, eggs, insects, or meat.  Whatever the answer, is is doubtful that it could be answered now, and it is likely that only further research, and more discoveries, will ever hope to unravel the mystery surrounding Propleopus, the seemingly killer kangaroo.