Exotic Animals

I got to meet, and help care for, a baby wallaby.

A few years ago, in the winter of 2001, I had the opportunity to help care
for a baby wallaby.  Why the chance came up is a long story; it will suffice to
say that I couldn’t turn it down.

So what’s a wallaby, and what kind of care do the babies need?

Wallabies are marsupials, native to Australia, and closely related to
kangaroos.  The main difference between wallabies and roos is size; while
kangaroos are person-sized or larger, wallabies are usually no bigger than a
medium sized dog.  Like all marsupials, wallabies are born at a very early
stage, and the mother holds them in a pouch until they mature enough to take
care of themselves.

Wallabies are herbivores.  In the wild, they graze on various grasses, and
browse on small shrubbs.  They are bipedal hoppers, meaning they move their back
legs in unison, and they have a long, heavy tail which helps to balance them
when they hop at full speed.

It’s illegal to export animals from Australia, but wallabies will breed
readily in captivity, and there are several breeders in the US, especially in
the western states.  The original stock was brought to the US before Australia’s
export ban went into effect.

The wallaby that I helped to foster was a few months old, and male.  He was
no longer nursing, so I didn’t have to bottle feed him, but he did have a big
quilted pouch that he didn’t like to leave.  He enjoyed being carried around in
the pouch.  He ate various grasses, moslty timothy, which are readily available
at pet stores as rabbit food.  He also enjoyed root vegetables, particularly
carrots.  He would eat these right from my hands.

When he wasn’t being carried around in the pouch, or allowed to run
supervised around my apartment, he lived in an ordinary porta-crib.  A heavy
blanket over the top kept him from jumping out, and an ordinary rabbit water
bottle was available when he got thirsty.

He was a pretty cuddly little guy, but not very smart, and not
house-trainable.  I won’t talk abou the cleanup required….

I wouldn’t recommend keeping a wallaby unless you have a ranch to let him
run.  This is why the breeder are mainly in the west; they can house the animals
outdoors, in a similar habitat to what they came from.  Still, helping to foster
this baby was an amazing experience.

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I saw a news articles on Yahoo News about a Georgia aquarium that keeps whale
sharks.  Well, actually, the article was about how they failed to keep whale
sharks… They’ve had two die in the last few months.  You can read the link
here:  http://news.yahoo.com/s/ap/20070613/ap_on_sc/whale_shark_dies;_ylt=AvwkMwHazr_wOWMp7Hh_pjXMWM0F

After I read this, I was wondering: Just what is a whale shark, and why are
they so hard to keep in captivity?

As the fish’s name suggests, whale sharks are the shark equivalent of baleen
whales.  They are big (growing up to 40 feet long), and they are plankton-eating
filter feeders.  They are found in tropical seas, worldwide, usually near the
surface.  They are harmless to humans.

Like all filter feeders, whale sharks have an enormous mouth for their body
size; their mouths can be over 4 feet wide.  Unusually for sharks, their mouths
are also at the very front of the head, instead of on the underside; this allows
the shark to simply open its mouth while swimming to suck in the huge volume of
water they need in order to filter out enough food.  Remember, these are 15 ton
animals, which eat some of the very smallest prey available.

Whale sharks have an ingenious adaptation for filter feeding.  Like all fish,
they have gills.  The external features of gills are obvious to humans: the
slits along the sides of the animal, just behind the head. Internally, however,
gills have a very complex, comb-like structure, designed to get the maximum
water flow over tiny blood vessels, so that the animal can extract oxygen from
that water.  This structure is a good pre-adaptation for filter feeding.  (I may
talk about pre-adaptation in a future post; it is a fascinating subject in
evolutionary biology.)  The whale shark will eat anything which the internal
gill structure traps in the mouth.

While I was looking up information about whale sharks, I came across several
references to Thor Heyerdahl’s famous Kon Tiki expedition, when he sailed a
primitive raft across the South Pacific, and proved that human colonization of
the Polynesian islands was technically feasible for Stone-Age people.  During
the trip, he had an encounter with a whale shark, which he described as the
biggest and ugliest face any of us had ever seen in the whole of our
lives.

Whale sharks might not be pretty, but they are fascinating.

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I found this story the other day, while I was looking through some back news
articles, and it struck my fancy…  It’s about a fisherman in Indonesia, and
the unusual fish he caught…

http://news.yahoo.com/s/nm/20070521/od_uk_nm/oukoe_uk_indonesia_fish

He caught what may be the world’s rarest fish: the ceolacanth.  This fish is
only known to live in deep waters of the Indian Ocean, near the Comoro Islands,
or in deep waters of the Indonesian archipelago.  It is a unique animal in many
respects.

First, and most famously, it was thought to be exctinct since the time of the
dinosaurs.  In 1938, however, one was caught of the southeastern coast of
Africa, and when it was identified, by the South African ichthyologist Marjorie
Courtenay-Latimer, the hunt began to find it’s natural habitat.  This was later
discovered hundreds of miles north of the original find, around the Comoro
Islands.  Later, in the 1980’s, another population of ceolacanths was discovered
in Indonesia.

The fish is also famous, though, for its position on the evolutionary tree. 
The ceolacanth is that most rare of beasts: a true missing link.  In this case,
it’s a link between early fish, and early terrestrial animals.

The ceolacanth has very unusual fins.  Instead of a fin supported by numerous
rays, a ceolacanth’s fins are supported as a fring around a stout, limb-like
appendage.  The fish has four of these appendages, two pectoral and two pelvic. 
The analogy to fore- and hind-limbs is obvious, and scientists believe that all
modern land dwelling animals arose from a fish in the ceolacanth family.

This is an exciting find; as the article notes, ceolacanths cannot live in
surface waters; the temperatures, pressures, and light levels are all wrong for
them.  Their natural habitat is at least 60 meters (almost 200 feet) below the
waves, and they have never been successfully kept in captivity.  In their own
habitat, ceolacanths are dangerous predators; at the surface, they prove to be
surprisingly fragile.  This could explain how these fish stayed hidden from
human eyes for so long.

And that’s all I have to say about this.  Animals don’t get much more exotic
than the ceolacanth.

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You’ve probably heard about this already; it’s been in the news on and off for the last few weeks.  Two humpback whales swam up the Sacremento River, and hung out for a while.  Here is a news article about them:

http://news.yahoo.com/s/ap/20070521/ap_on_re_us/delta_whales

It’s not really unusual for large whales to come close inshore; it is unual for them to swim upriver so far. The last tiem a humpback spent so much time in the Sacremento River was in 1985.  The two whales this time are apparently a mother and calf, and made it more than 20 miles upstream before they turned back to head for the ocean.

As the article notes, they both have wounds which may have come from boat propellers.  This is a common hazard for inshore aquatic mammals.  In south Florida, where a lot of people have boats, and a lot of boat channels are inhabited by manatees, propeller injuries are common.  Even dolphins, cetacean relatives of humpback whales, are sometimes hit by boats.

Whales like these, however, are less frequently injured by boats.  For starters, humpbacks are big, up to 60 feet long, making them easy to see.  Also, these large whales can dive deeper, and stay down longer, allowing them to avoid surface craft.

It’s not likely that the propeller wounds will prove life-threatening to either whale.  Whales in general, and large whales in particular, possess thick layers of blubber directly under their skin, which serves the dual purpose of insulating the animal in cold water and armoring the animal against injuries.  Blubber injuries to whales usually heal and leave the animal with no lasting problems.  The main problem with such injuries is infection.  This is more of a problem for these whales, since the river they’re in now is not as clean as the open ocean.

I’ll post more about these whales later, if they ever decide to leave leave the river…

Crocodilians have alwas fired the imagination.  They’re big, fierce, and reptilian, all features that inspire fear in many people.  They are also fascinating animals.

Excepting some of the giant constrictor snakes, crocodilians are the world’s largest predatory reptiles.  They can be found through most of the tropical and subtropical regions of world.

The continental US has two native species of crocodilian: the American crocodile, whose range is restricted to small area in the sourthern tip of Florida, and the American alligator, whose range extends from the Atlantic tidewater region, through the Georgia Sea Islands, the Florida Everglades, the Gulf Coast, and the Mississippi Valley.  It’s most common in the Gulf region.

Alligators are freshwater, semi-aquatic predators that can grow up to 8 or 9 feet long, and weigh more than 800 pounds.  They were once on the brink of extinction, but in recent decades they’ve been making a come-back.

I’m talking about alligators because I found a neat news article today: http://news.yahoo.com/s/ap/20070513/ap_on_fe_st/odd_albino_alligator

Apparently, there is a reptile zoo in St. Augustine Florida that specialized in breeding alligators, and one of their breeding pairs produces several albino gators every year.

To me, this is interesting for a couple of reasons: first, because albinism is a rare genetic mutation, these albino babies are probably produced by the same parents, year after year.  This implies that alligators may mate for life, or at least come back to the same mate perferentially.  This is not a mating habit associated with reptiles; it is more common in birds and mammals.  And the crocodilians are the closest living relatives of birds.

Second, it’s just cool.  Take a look at the picture of the white alligator, in the news article.  That’s just plain neat, isn’t it?

I’ve written about dogs in this blog, so now I’ll write a bit about cats.

I’m a cat person.  Well, actually, I’m a bird person, but I grew up as a cat
person.  My family got a cat in 1979, a few weeks after Mom saw a mouse in the
basement.  I remember that there was another mouse in the house, around 1982,
but that was  the last time.

That cat was a great pet.  I was 5 or 6 when we got her, and my sister was
two years younger, and that cat was perfect for us: very mellow, very
laissez-faire, very, very patient, and tough enough to scratch when the
occassion demanded it.  With me and my sister, the occassion demanded it pretty
often, until we were both in junior high.

She was a pretty cat, too: part Persian, and part alleycat.  It was an odd
combination, but she definitely came from the deep end of that gene pool.

When my sister was in high school, she brought a kitten home.  This cat was a
contrast to its older housemate.  We started calling the new kitten the
non-wonder cat, after she chased her tail, caught it, bit it, and turned around
to see who bit her.

She was a sweet cat, in her own way.  She liked to curl up next to people on
the couch, and she always knew when the humans were going to get up; she’d get
up, herself, about 30 seconds before, to avoid having her seat disturbed.

Both of these cats are gone now, and my current pet is a parrot, but I do
remember them fondly.

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They may not be exotic, but they are amongst the world’s most popular animals…so I have to mention them.

Dogs are not my favorite.  Anyone who knows me, knows this.  In fact, my earliest memory is getting bitten on the head by a dog.  I remember it as a giant, 200 pound, slavering, man-eating beast.  My mother tells me that it was just a small puppy.  Amazing what a difference in viewpoint of 30 years can do, isn’t it?

So why am I talking about dogs?  Well, I’m staying at a friend’s house for a few days, while my place is undergoing some much needed renovations and repairs, and this friend has a dog.

A mutt.

A big mutt.

Well, not that big.  But big enough.  And he slavers.  Sometimes.

OK, he’s a ordinary, average sized, stray born, mutt.  And he’s friendly.  And he likes me.  But it doesn’t change the fact that, when I see this black shadow walking through a darkened house while I’m on my way to the bathroom at 2am, my heart jumps.  And then the dog rubs against my legs like a cat.

I think that he thinks he’s a cat.  There are a lot of stray cats in this neighborhood.

I’ll be glad to get back to my own place, and away from the dog.  He’s a friendly dog, and he doesn’t hump legs or bite hands, but he’s still a dog.  Even though he’s growing on me.

 I was browsing through some old science news stories, looking for something to post about, and I found this:

http://www.msnbc.msn.com/id/17746419/

Tiny rare owl spotted in Peru reserve

Long-whiskered owlet discovered in 1976, but has not been seen in nature

Sometimes, I try to post about generalities, and sometimes I try to post about just really cool stuff.  This is definitely really cool stuff.  This is why I used to get “up north” in Michigan and go out at the crack of dawn with binoculars and a breakfast bar.

OK, so I never found a rare species, but I did see nesting Canada geese, ravens, and, once, a bald eagle.  I always kept a record of what I saw, when I saw it, and where I saw it.  There was never anything as exciting as this owl, but the eagle was a most impressive bird, and striking hawks are unforgettable.  I can definitely understand the thrill these ornithologists got, when they realized what they had:

The group [American Bird Conservancy] said the sighting “is considered a holy grail of South American ornithology.”

“Seeing the long-whiskered owlet is a huge thrill,” said David Geale of the Association of Andean Ecosystems, who was a member of the research team. “Its population is estimated to be less than 1,000 birds and possibly as few as 250.”

That tiny population, and the threat of habitat destruction, are why this bird went undiscovered until 1976, and why it has never been seen in its natural state until now.  It’s a story similar to the Large Billed Reed Warbler that I blogged about before.  It makes you wonder what else is out there, that we just don’t know yet…