i (heart) odd-toed ungulates

Underneath the Tuxedo

Sketch, from a recent NEAQ penguin-watching expedition... Luckily, the aquarium has a neat little penguin skeleton nearby the live animal exhibits, so when one attempts to ponder the underlying anatomy of such funny birds, she needn't look too far. Unfortunately, the angle I was drawing at lent a decidedly sinister perspective to the skeleton's posture - a decided conrast to the waddling, comedic character of a penguin in the flesh... (gotta love sketchbook surprises).

Big Boys, Little Ladies: Sexual Dimorphism in Fur Seals

Visiting my favorite little pinnipeds last week (the Northern fur seals at the NEAQ), I was struck once again by the extreme size difference between the males and the females of the species. At a glance, it would be easy to assume that the slick, smaller individuals in the exhibit - swirling around the pool like dark little dolphins - were juveniles. Compared to the two, massive, bristled, brown lumps sprawled at one end of the deck, the lithe little creatures almost seem another species entirely... but to assume this would be incorrect.

Sexual dimorphism* defines the phenomenon whereby notable physical differences exist between males and females of the same species (other than obvious sex organs). The ornate antlers of a bull elk, thick mane of an African lion, and proud fan-tail of a peacock are all evidence of sexual dimorphism at work. Through observation of countless species, Darwin argued that sexual dimorphism was a result of sexual selection and occurred most prominently in polygynous species, where single males have the opportunity to "win" reproductive dibs over mutiple females. Sexual selection can occur via direct competition: the larger a bull elk's antlers and more well muscled his physique, the more successfull he will be in defeating other males and gaining access to cows; or female choice: the showier and more brightly colored the peacock's tail, the more likely he will be in winning the eye of discriminating peahens. In both cases, selection favors a distinctly different morphology for males than it does for females.

*Reverse sexual dimorphism occurs when females are larger or more ornate than males (not common in mammals, but can be found in many species of insects and fish).  


Northern fur seals (Callorhinus ursinus) are polygynous. During the weeks of a breeding season, the most experienced adult males (bulls) stake claims to the most desirable spots along the beach, aggressively defending their square footage from neighborning males. As females arrive and select their choicest real estate, they become prizes within the territories - a single bull eventually holding control of up to 50 females (cows)... he'll exhaust himself displaying, fighting and mating, and he'll fast until the season is over - too dedicated to propagating his genes to risk stepping away for meals and loosing his resources. Such social/behavioral circumstances clearly favor a male's size, strength, and endurance, and as a result, the average bull is up to 5 times heavier (reaching 600lbs) than the average female (at a rough 100lbs), and with a 30-40% longer body length (*on account of the fasting, the heavier the male, the more weight he can loose without it effecting his performance). With their powerfully thick, well-muscled and maned neck and shoulders, male fur seals are a sight all on their own - set next to their mates, however, they become relative behemoths.


Hundreds of miles from their native North Pacific home, and world's away from the natural dynamics of a wild fur seal colony, the female fur seals at the NEAQ cavort and curiously interact with visitors through the exhibit glass; the boys - confidently languid - rouse only when an itch compells them to curl a flipper across their bodies for a good scratch.

The online treasure trove of wildlife imagery, Arkive.org, has a great slideshow of Northern fur seal photos (including the 2 below by photographer Tom Vezo), as well as some compelling video footage. In this clip, a large bull defends a single cow from 2 tenacious rivals. If you've ever clambored over a rocky beach and tried not to break a leg or abrade limbs in a trecherous slip, you'll appreciate how bad-ass these animals are - chasing, body-slamming, and viciously harassing each other over such dicey terrain... and on an empty tank no less! Bad. Ass. For more reading on fur seals, this article provides a thorough exploration of the role of aggression within breeding colonies - I also wrote a post in early 2010 - inspired by the same NEAQ "family" of animals, but following a fascinating tangent into early marine mammal conservation, which fur seals, coincidentally, inspired. 

Aquarium Zen & the Brilliance of Cephalopods

The octopus exhibit has always been a favorite destination at any aquarium that I visit. More often than not the beast is crammed up into one corner of it's "cave", looking completely, indignantly bored with it's life through unblinking eyes... and unlike most of the simple fish, robotic crustaceans, and literally brainless jellies and sponges that surround it, the octopus, I know, is sincere in it's expression.

Cephalopods in general (including cuttlefish, squid, and octopuses) are known for their intelligence, and octopuses specifically are some of the most crafty - their spacial learning skills, navigational ability, and tool use has been well documented. Similar faculties have been lauded in many mammal species, but are somewhat even more remarkable coming from creatures without a backbone (for comparison, fellow invertebrates include oysters, snails, and slugs...). The NEAQ actually takes pride in the story of a legendary octopus that would escape it's tank each night, crawl across the floor and hunt and consume members of a single fish species in a neighboring tank (once discovered, a heavy weight on the top of the tank lid was enough to keep the critter in). On account of this propensity for mischief, some aquariums provide their 8-legged wonders with "enrichment" puzzles: elaborate, maze-like, or well latched containers requiring thoughtful, or just amazingly dextrous, solutions to obtain food rewards. The recent story of Paul, the World Cup oracle, contained a perfect example of "themed" octopus enrichment, albeit with somewhat higher stakes...


The drawing at the top of this post is of the NEAQ's Giant Pacific octopus, Athena, during a rare moment of affection with a keeper - the disembodied hand reaching down from above is that of a staff aquarist. The suction cups on an octopuses tentacles contain chemical receptors akin to a nose or mouth (in addition to their obvious tactile reconnisance) - they're so sensitive that they can distinguish between individual humans. Athena clearly had good rapport with whomever was giving her back scratches that day, clamoring and squirming at the surface of the water when the hand was removed, then sinking into blissful suspension with it's reappearance.

Unfortunately, the life span of most octopuses, even the largest, and even in captivity, is only between 3 and 5 years. At 3 years old, Athena is getting on in cephalopod time... but she's a sight to behold, no less. Click here to read more about the wonders of suction cups, and see a GPO from the Georgia Aquarium using it's well suctioned tentacles to maneuver across the glass of it's tank.

And now for your moment of aquarium zen...

Make Way for Penguins

I'm really loving my 2010 membership at the New England Aquarium - it's a joyful thing to be able to stroll in on a Friday morning on my way home from the dentist; spend a few hours drawing, catch a training session with the fur seals, and bask in the tranquility of tropical tanks... then make a break for the exit just as the crowds reach maximum capacity and start to turn a good thing into an utter annoyance. Add to that a slight detour into Modern Pastry for a cannoli on the way back to the T, and you've got yourself one bang-up morning - with plenty of day left to work back into the sketchbook and frolic through Photoshop... Boston, slowly but surely, you're winning me over.
 

Sketchbook : Penguins & Sea Dragons

More drawings from the New England Aquarium: Rockhopper penguins, a weedy and a leafy sea dragon (in purple pencil), and a pygmy crocodile (who is actually a tagalong from a day at the zoo...). Penguins are generally a lot of fun to sketch - simple silhouettes, but between grooming, squabbling, darting around underwater, and hip-hopping around the rocks in their exhibit, they offer up a surprising amount of gestures, and as much expression as birds are capable of. And if you're ever at the NEAQ, you must, must, must check out the sea dragons - they are by far one of the most brilliantly beautiful and incredible fish you'll ever see. Sea dragons are native to the southern and western coasts of Australia and belong to the same family as sea horses - as evidenced by their long snout and gracefully arched necks. The Weedy sea dragon (Phyllopteryx taeniolatus) is painted in a contrasty array of canary yellow, neon blue, glowing orange and deep purple, and has a sleek, undulating body that sprouts a handful of oar-shaped, "weed-like" projections from head to tail tip. By contrast, the yellowy-orange colored Leafy sea dragon (Phycodurus eques) is completely covered in ruffly protrusions and looks remarkably like a dense cluster of drifting kelp strands. Sea dragons lack the prehensile tails of their cousins, the sea horses, but like sea horses, male sea dragons are tasked with safeguarding their mate's eggs after fertilizing them; instead of using the sea horse's kangaroo style pouch to incubate the eggs, sea dragons have a spongy "brood patch" on their tails to which the eggs are attached and receive oxygen through for roughly nine weeks until they hatch.

I decided not to work color into my above sketch, but after a little photo research online I found this beautiful painting of weedy sea dragons by the incredible 18th century natural history artist, Ferdinand Bauer (image from the collection of the Natural History Museum, London). Bauer accompanied the famous Flinders' expedition of 1801-1803 - the first voyage to cicumnavigate Terra Australis, the island continent of Australia (then called New Holland). Working closely with on-board botanist Robert Brown, Bauer generated a remarkable 1500+ drawings of Australian flora and fauna (and hundreds more from specimens collected on surrounding islands), including marsupial mammals, colorful parrots and tropical fish. Studiously true to nature, Bauer has even drawn one of the fish in his painting with a thick row of eggs lining the underside of it's tail...
  

Henry Wood Elliott & the Fur Seals

The New England Aquarium recently opened a new Marine Mammal Center, featuring Northern fur seals. The space has a few good viewing areas for getting right up close to these impish little pinnipeds, and the lighting is almost entirely natural (the exhibit is partially outdoors), which makes observation and drawing much easier. The individual sketched above was quite vocal, regularly waddling himself up to the glass and making sure he had an audience gathered before belting out a great belch of a bark. Seal and sea lion voices have always seemed startlingly improbable to me - like a cruise ship's horn from the mouth of a squirrel...  

After doing a little post-drawing research on fur seals, I came across the work of late-nineteenth century American artist and naturalist, Henry Wood Elliott. A native of Cleveland, born in 1846, Elliott served a number of years as a staff artist for the Smithsonian, traveling the Northwest coast with survey expeditions; though not professionally trained, he had a deft way of capturing the world around him in his drawings. In 1872 he was appointed by the Secretary of the Treasury to conduct a thorough scientific study of the fur seal population, and oversee their harvest, in Alaska's Pribilof Islands - fur seal populations throughout the rest of the world had already been ruthlessly decimated by hunters and the U.S. desired a practical assessment of the remaining resource (read: commercial value) within it's newly acquired territory. Elliott eagerly took the job and immediately fell in love with the landscape and wildlife of Alaska. In addition to exploring the animals at the heart of his study, much of his artwork depicted aboriginal Alaskans engaging in traditional activities - images the general public of the late 1800s had never seen. During this time, Elliott also keenly observed and recorded what would by today's standard's be considered appallingly horrific assaults on nature: Victorian era seal hunts. Below are a handful of Elliott's line drawn illustrations (fur seals, a sea lion hunt, and walruses) from his 1882 book, A Monograph of the Seal-Islands of Alaska. I get a painful, angry lump in my throat looking at Elliott's depictions of those hunts, I can't begin to imagine watching such brutality transpire in person, day, after day, after day. 
    

Elliott's survey of Alaska's fur seals was comprehensive, and enabled him to propose annual hunting quotas that could satisfy demand while preserving the future of the herd; but his management plan was quickly circumvented by greed and the seal population continued to plummet as sealers began killing at sea (unprotected territory) and cruelly preventing the animals from taking refuge on land. As witness to this steady slaughter of hundreds of thousands of seals, Elliott, a compassionate naturalist, became vigorously involved in conservation efforts to halt the hunts altogether and save the species from likely extermination (and the simultaneous destruction of native Alaskan subsistence needs). Finally, in 1905, after years of exhaustive political appeal, Elliott co-authored a landmark document with U.S. Secretary of State, John Hay, that eventually became the very first international treaty dedicated to conserving wildlife; the document would become known as the Fur Seal Treaty of 1911 and would serve as a model for future decades of conservation legislation, including the great Marine Mammal Protection Act of 1972. The painting below ("Aleutians Striking Humpback Whales: off Akootan Island, Bering Sea," undated) is in the collection of the Smithsonian's NMNH. 
   
 
These days, it isn't rare to see artists become environmentalists - or at least provide profound visual commentary on the future of humanity's increasingly poisonous intersection with nature - but my hat goes off to Elliott for blazing this trail before the concept of conservation even existed. And the fur seals rejoice.