Wednesday, February 15, 2012

Sweet Transvestite from Sepia Apama

Crossdressing is a tangled and complicated part of human history. It's a practice that's existed as long as we've worn clothes, but it's also a surprisingly common tradition in the animal world. There are plenty of possible reasons for this, from transitions between normal and breeding appearance to outright conditional hermaphroditism. But few creatures are much more... renowned for this interesting behavior than the Australian Giant Cuttlefish.

Hey sailor!
The giant cuttlefish, the largest species of its kind, is a master of camouflage. Its eyes are highly advanced, especially for an invertebrate, and it's capable of changing the color, texture and overall shape of its body on a moment's notice. This species also suffers from a remarkably skewed gender ratio: they have about eleven males hatched for every one female. Consequentially, competition among males is very high, and this rivalry has lead to the development of some peculiar reproductive tactics.

♪ One is the loneliest number that you'll ever do... ♫

In order to monopolize whatever mating opportunities they can get, male cuttlefish become very territorial in spawning season. They'll reign off the biggest chunk of reef they can find and defend it with their lives, driving off any other fellas that dare set tentacle on their turf. So how do the smaller, younger males go looking for love? Simple: they disguise themselves as females. Breeding males will waste no chances to impress the ladies, and are more or less constantly flashing in brilliant, rippling hues with the help of their HD-TV skin cells. Females (and males wanting to impersonate them) maintain their usual subdued, sandy colors, to avoid drawing unnecessary attention from predators.

He might get eaten alive by dolphins, but he's gonna look fabulous doing it.

The smaller males use their girlish figures to sneak into other males' territories and court their females. Just for perspective, the human equivalent of this behavior would be for a reedy guy to walk into a ganglord's hideou dressed in drag and hope for the best. Since giant cuttlefish are polyandrous (females mating with multiple males) this works out pretty well for everyone but the dominant suitor. All he can do is patrol his territory to the full extent of his boneless strength and keep an eye out for any suspicious goings-on in his harem. Like most cephalopods, cuttlefish will die at the end of their breeding cycle: leaving behind a new generation of bruisers, brains and dubious 'females'.

Nope, no menfolk around here. Never seen them. No idea what you're flashing about.

Monday, December 19, 2011

Bloody Weird

 First, let me apologize for my long absence by saying that I am immensely proud of every single hit this website gets and wouldn't abandon it for the world. I've been dealing with a bit of writer's block lately, and it's kept me off of less demanding projects like WTFNature. But rest assured that I have no intention of shutting it down, and hope to update more in the next few weeks.

Now that the sappy part is out of the way, let's talk about bodily fluids. More specifically, blood and its numerous analogues found throughout the animal kingdom. The purpose of blood, as we all learned in gradeschool, is to carry vital nutrients and oxygen through a body in the most effective way possible, feeding the cells and facilitating all the chemical reactions that allow us to live. In humans, blood begins pumping through our veins about 6 weeks after conception: that's long before we develop hands, eyes, lungs or a functional brain. Among vertebrates, the heart and the spine are basically the two structures around which the rest of the body is built. Different branches of life utilize different but equally important modes of transporting things around the body, and that's what we're here to discuss.

Unfortunately, we didn't have enough room for Vulcan biology in this article.
Virtually any animal that happens to have a spine is guaranteed to have red blood. (There are a couple of exceptions to this statement, but more on that later.) However, the same cannot be said for invertebrates, who bleed a lovely array of  hues from dark blue to yellow-green. It all has to do with the blood's primary oxygen binding molecule. Vertebrates employ a compound called hemoglobin, which is based in iron and therefore turns scarlet red when oxygenated. (It's the same reason that iron and steel products rust: iron atoms bind with oxygen to create a new, bright red compound.) But invertebrates have a variety of different oxygen binders, most of which are based in copper rather than iron. The most common type of copper-based blood is called hemocyanin, which is naturally transparent but turns bluish-green when oxygenated, just like corroded copper. (Picture the Statue of Liberty.)

Cold-blooded heifer.

While hemoglobin is always neatly packed away in red blood cells, hemocyanin gets no such distinction. It just floats freely in the animal's circulatory system, which, also unlike ours, does not have separate blood and lymphatic systems. All the important life-maintaining liquids flow though the same vessels as a thin substance called hemolymph. Though it's probably been around much longer in evolutionary terms, hemolymph is less efficient at storing and transmitting oxygen than hemoglobin, and this is one of the chief reasons invertebrates are limited in their overall bodily mass. Unlike vertebrates, insects and arthropods just can't circulate oxygen well enough to fuel a larger body. In addition to being crushed by their own weight, (thanks for ruining our best sci-fi monsters, Square-cube Law,) a hypothetical giant invertebrate would suffocate from the inside because its cells couldn't get enough oxygen to support them.

We would've taken over the world if it wasn't for you meddling vertebrates and your fancy hemoglobin!
So why is it that octopi bleed bright blue while grasshoppers ooze that sort of leafy green? There are a ton of different hemolymph compounds out there, and explaining each and every one of them would take more space than this whole blog could provide. (Not to mention be extraordinarily boring, even by my standards.) To put it shortly, different families of invertebrates use different mixtures of hemocyanin and other compounds to get the job done. Mollusks and many other marine animals have a high concentration of hemocyanin, which makes their blood appear greenish-blue and allows them to survive with their relatively flimsy gills. Most insects don't even circulate blood: they just take in air from their spiracles (openings in the exoskeleton) and pipe it directly into their tissues.

We can kinda sorta breathe!

But that is more than enough about invertebrates and how their various liquids work. In fact, if you're still reading at this point in the article, congratulations because you probably have a longer attention span than I do. Alright, so what about the bigger, more interesting animals? Is there anything going on there that we haven't already seen? Indeed there is, and its name is Prasinohaema: the green-blooded skink. Skinks (let's take one more opportunity to giggle at that word, because it pops up a lot,) are a type of lizard, characterized by long, snakelike bodies and stumpy legs, that are painfully common in certain parts of the world. In fact, some groups are banned in Australia because they risk becoming an invasive species, and the last thing Australia needs is more invasive species. The green-blooded skink is so mundane in New Guinea that you can't walk through the woods without bumping into them, but they also hold a unique biological anomaly in boasting the greenest innards the vertebrate world has ever seen. For reasons still not fully understood, these little lizards have an outrageous amount of biliverdin, a pigment normally found in bile that, in the right light, looks positively lime green. Biliverdin is more of a metabolic byproduct than a functional compound, and scientists are baffled as to why the green-blooded skink can be completely seeping with it and not die. Theories suggest that the strong bile presence protects the skinks from parasites and makes them unpalatable to predators, but that's the only explanation we have so far. Exactly why and how their entire chemistry has been rerouted to accommodate the skink's poisonous tissue, we are unsure. The one thing we do know is that stepping on one would be absolutely vile.

What are you planning, alien scum?

Wednesday, October 5, 2011

Turtle Rabbits

Today we're going to talk about the peculiar little chimeras called armadillos. "Armadillo" comes from the Spanish words meaning 'little armored one', while the creature's native Nahuatl name is the much less flattering "azotochtli", or 'turtle-rabbit.' Docile burrowers who are often treated as pests, armadillos decorate belt-buckles and freeways all across the American south. But there's a lot about the humble armadillo that isn't common knowledge, and that's what we're here to discuss.

Like their numerous practical applications.

 For one thing, the dim, innocent armadillo is also a carrier of one of the most feared diseases in history: leprosy. Simply coming into contact with one (or eating their delicious, delicious meat,) is enough to cause a good chunk of the leprosy cases in the Americas. Armadillos make ideal carriers for the bacteria because their average body temperature is quite low by mammalian standards; a cozy 93° at rest. This happens to be the climate leprosy germs thrive in, and it's also roughly the same as a normal human's skin temperature. One bite or scratch from a disapproving armadillo is all it takes to infect someone... Even though the vast majority of the human population is naturally immune by now, which kind of kills the drama.

Disgusting. It's like a walking biohazard.
But the leprosy issues are nothing compared to the armadillo's unique reproductive habits. Most of the Cingulata (armadillo) order are pretty straightforward in this regard; but the Nine-banded Armadillo (one of the most common species in North America,) breaks the mold. Aside from having a delayed implantation time, and therefore a confoundedly long gestation period (8 months), the Nine-banded Armadillo is the only mammal in the world that routinely gives birth to clones. For reasons still not fully understood to science, most litters of Nine-banded Armadillos consists of exactly four offspring, all genetic carbon-copies of one another. That means that every one of these animals you'll ever see was most likely born with three identical siblings. Fraternal siblings do happen, but they're very rare, and quadruplets are by far the norm for Nine-banded Armadillos. Scientists love to capitalize on this quirk for research purposes: armadillos are the only mammalian species that is guaranteed to produce four interchangeable test subjects with each breeding. I'm not going to touch on the subject of animal experimentation. It's too thorny, and the primary purpose of this blog is to be educational and fun. But one thing is certain: there's a lot of potential to learn about genetics and gene-based behavior by studying the wonderful armadillo.

Such majesty.
 And so, I'll conclude this post with a little random armadillo trivia that I just couldn't stuff into the main article:
  • Armadillos have proportionally large eyes, but terrible vision.
  • The Pink Fairy Armadillo can bury itself in seconds if threatened.
  • Nine-banded Armadillos have the unfortunate habit of leaping when startled: they tend to jump about fender-height when spooked by an oncoming car.
  • An animal called the Screaming Hairy Armadillo exists. It's covered with bristly hair and screams horribly if frightened.
  • Armadillos cannot swim normally; their armor is too heavy. To cross a body of water the armadillo must first swallow a sizable volume of air, to inflate its digestive tract like a balloon and make itself light enough to float. 
Clint Eastwood approved!

    Thursday, August 4, 2011

    Butterfly Bachelor Chow

    Lonely males, regardless of phylum, are not known for good eating habits. But they do typically stay within the parameters of their species normal diet: bored eels just aren't chowing down on seaweed. Butterflies are an odd exception, though, as we will shortly discuss.

    Every first grader knows that butterflies and the varieties of moth that do eat all feed by fluttering from flower to flower and drinking nectar. Their larvae feast on a wide range of leaves, like the monarch caterpillars eating toxic milkweed to make themselves unpalatable to predators. However, the adult males of several species will also descend on some... less savory dishes; such as urine puddles, feces, and the carcasses of larger animals. Even though they don't contribute any immediate energy, lapping at these foul sources has an undeniable benefit for these males. They are rich with the minerals, proteins and amino acids that flowers simply can't provide.

    But the real significance of this behavior comes out in courtship and mating. When certain butterflies mate, the males will inseminate the female with a packet called a spermatophore. This 'nuptial gift' contains not only the sperm but a dose of vital nutrients, namely the minerals and proteins that they worked so hard to collect. These compounds are imperative for the healthy development of eggs.

    Tastes like chicken! ...Well, a certain part of the chicken.

    Some females, however, will cheat by mating with multiple males to collect their nuptial gifts, but only producing offspring for the last of the set. Several families have means to combat this, such as a pheromone signature that makes a non-virgin female unattractive to other males, or a mating process that makes it physically impossible for the female to mate twice. Either way, males of many species will do their best to see that their labors of scavenging sweat and other bodily fluids doesn't go to waste.

    So remember fellas, having to buy your girlfriend a bouquet or some chocolate every now and then isn't so bad. If you were a spider, you'd probably be eaten by your belle once you'd outlived your usefulness; and if you were a butterfly you'd spend days of your brief life sucking on poop in hopes of having babies that survive infancy.

    Saturday, June 11, 2011

    Geoduck: Great Mascot, or the Greatest Mascot?

    We here at WTFNature are dedicated to sharing informative articles on the wonders of the natural world. Today's feature is a hardy little bivalve known as the geoduck (that's pronounced "gooey duck.") These animals can live over 100 years--

    --in fertile saltwater all around the world. Their long siphons are used to peacefully filter debris particles for food and they, unlike most mollusks, are not--

    --hermaphroditic but gendered. Breeding for geoducks is very slow and unreliable, as only a small fraction of their eggs are fertilized and an even smaller portion of these live to maturity. Also known as mirugai or long-necked clams, geoduck are used--

    --all around the world in a multitude of dishes. They're an obscure but valued ingredient in some French sweetbreads, sliced thin in Japanese sashimi and served many ways in Chinese cuisine, usually as--

    --a lovely fondue-style hotpot. Farming and selling geoducks is a major business in the Northern US and Canadian seaboard, mostly in Washington and British Columbia. It takes many years for the animals to mature from tiny bud-like nymphs into edible adults, and they sell for--

    --up to $3 US per lb. Evergreen State College of Olympia honors the geoduck as their official school mascot. They earned the position because of the school 's motto, Omnia Extares (or, "let it all hang out,") as a--

    --reference to their carefree, sedentary lifestyle. In short, the geoduck is a humble but sadly unappreciated creature that plays an important role in our economy, environment and academic scene. The unofficial motto of our site is 'give credit where it's due,' and today we honor the noble geoduck for its subtle contributions to the world.

    Friday, June 3, 2011

    Hyena Sexism

    What do you first think of when you imagine hyenas? Their cackling voices, their notorious reputation as scavengers, their role as antagonists in every story that mentions them? There's so much about these animals that many don't know, and all the most interesting parts seem to have been omitted from public perspective. Spotted hyenas are highly intelligent creatures who live in a complex hierarchy, and much of their social habits seem to have risen from some strange ultra-feminist text of the sixties.

    Negative stereotypes.
    You see, spotted hyenas (the most common variety,) have a matriarchal society; meaning that their packs, or clans, are lead by a female alpha. This isn't too unusual in the animal world: bees and ants seem to have run a matriarchal super-empire for eons now, and elephant herds are always guided by the oldest, wisest grandmother in the group. But hyenas stand out because not only does their social structure lean in the womens' favor, their biology actually supports and reinforces this behavior.

    Centuries ago, when European explorers first came upon the hyenas, something about their organization seemed strongly amiss. Try as they might, even the best medieval naturalists just couldn't locate a female of their breed. Every hyena they found was stockier and fiercer than the last, and their external sexual anatomy looked... pretty damn masculine. Dark Ages science being what it was, these people soon concluded that there simply were no female hyenas, and that they must be springing up randomly from the earth. (You know, the same way flies suddenly appear out of old meat.) Here's the root of a lot of the stigma surrounding these creatures: ancient "scientists" decided that hyenas weren't born naturally and therefore weren't made by God, but perhaps some unholy supernatural force. The four-legged witches having no way to defend themselves, this assumption hung around for hundreds of years.

    This animal's face is on the side of his head. Clearly he's not of this world.

    The truth is almost stranger than fiction. -Almost, science couldn't match medieval imagination this time. Obviously, there are female hyenas. I've already made reference to them so they must be real. Ancient scholars just never found them because their anatomy is so misleading. ...As much as we're all wishing to keep this site classy, the explanation here does involve a little bit of hyena gynecology, so skip through to the next section if you're squeamish. When you look at the backside of an adult hyena, (which I know you're all just dying to do,) you'll invariably see what appear to be testicles. Actually, females of the Crocutta genus have large, prominent labia, as well as an overdeveloped clitoris that looks and behaves like a penis. They can get erections and produce large amounts of androgens (male hormones) in their blood, which explains some of the typically 'masculine' behavior. This exotic equipment comes with its setbacks, as infant mortality and miscarriage rates for hyenas are exceedingly high, and about 10% of first-time mothers die in labor.

    Scientists are still unsure about why evolution shaped these charming shemales, but it might have something to do with their long gestation periods and high competition for food. Either way, it can be difficult for an observing human to discern the sexes unless you take into account that the females are noticeably larger and more aggressive than the males. (We only figured this out after a few much-needed dissections.) Basically, their society revolves around an inversion of the typical gender dynamic: the females are the big, domineering ones, who make kills while hunting and get first dibs on food. They pick and choose their mates from a list of hopeful males, and a potential suitor will only earn her paw if he expresses total submission to her. Females still take exclusive responsibility for their young, but any male who comes too close to them will be punished severely. They're essentially nature's real-life Amazons, with comparatively small, captive menfolk who they treat like trophies and boy toys.

    Get back in the kitchen and make me a sammich!
    Before anyone points out some unfortunate implications I might be stirring with the whole 'savage matriarchy' idea, keep in mind that hyenas are proven to be some of the most intelligent carnivores in world. Their society is richly tiered and their communication is much more advanced than that of canines or felines. IQ tests suggest that their social skills are on par with some monkeys in terms of complexity and efficiency, and one experiment even suggested they're better at group problem-solving than chimpanzees. Contrary to popular belief, they hunt just as much as lions do and actually have a higher predatory success rate, which means less carrion and more zebra for dinner. In addition, they don't have any of the infanticidal tendencies of the big cats: the usual cause of neonatal death in hyenas is infighting among litters, especially with same-sex siblings. (You thought our sibling rivalry was rough? Try fighting your twin to the death at two days old.) As I shrilled at you in the beginning, there's a lot of information about animals that isn't common knowledge, and I don't recommend forming your perception of an entire species until you know the facts. Now when you hear about hyenas, maybe you'll imagine their fearsomely effective Amazon brigades instead of those schmucks from "The Lion King."

    Friday, May 27, 2011

    New Zealand's Murder Parrots

    Oceania, as we all know, is home to some striking and unusual life forms. The marsupials in Australia, the Birds of Paradise in New Zealand, and the legions of horribly toxic monsters in every corner of the region. But one animal that stands out among the rich foliage and sheep jokes is the magnificent Kea. One of New Zealand's only parrots, (the other two, the Kaka and Kakapo, are also odd but considerably less interesting,) Kea are olive green in color, with orange splashes on the undersides of their wings and are highly clever, social birds. Their diet includes roots, berries, nuts, seeds, and, incidentally, sheep.

    A vicious killer on the prowl.
    Ever since people settled in the zoological wonderland known as New Zealand, strange things began to happen to their livestock. Sheep would intermittently turn up dead, with gaping wounds on their sides and bellies, despite the fact that the isle lacked any sizable predators. For a while, people were baffled, until they turned their sights on the only plausible culprit: Kea. The Kea had been known to eat plenty of carrion, and to occasionally hunt lizards and smaller birds for meat. They were established omnivores, numerous and wily, and they seemed to be the only viable suspect in the bizarre killings.

    Most naturalists dismissed the idea, saying it was impossible for birds, (even 19-inch long birds that travel in packs wielding razor claws and bone-snapping beaks,) to kill healthy sheep. Some conceded that maybe the livestock were dying naturally and the Kea, along with insects and other scavengers, would mutilate them post-mortem. But this theory simply didn't justify why perfectly normal animals were dropping dead out of nowhere: primarily sheep, but also dogs, cats, rabbits and even horses. For decades this remained a hotly debated phenomenon.

    It wasn't until 1993 that night vision cameras finally captured one of the deadly assaults. There, in the still of night, came the parrots. Approximately three or four of them descended into the field and hopped menacingly towards their victim. The Kea leapt onto a ewe's back and tore unrelentingly at her hide, her short neck and stumpy limbs leaving her powerless to stop them. The footage revealed that the Kea were actually digging around for the sheep's fat, just underneath her skin, and opened some impressive wounds in doing so. Injured sheep rarely died right away, but would eventually succumb to infection or gradual blood loss. This tape proved that Kea would attack perfectly healthy sheep for food, and it's not unlikely that they prey on other domesticated critters as well. Therefore, Kea are the only parrots in the world known to successfully hunt animals many times their own size.


    Aww, Polly wanna--

     So there you have it, folks: New Zealand's adorable slaughter parrots. They're intelligent, they're inventive, and they hunger for raw mammalian flesh. How long do you think it'll take before the rest of their avian brethren join forces and decide to go Hitchcock on our flabby, unprotected human asses?  

    UPDATE: We now have video of this grizzly phenomenon. Fair warning, it's pretty damn creepy.