i (heart) odd-toed ungulates

Carbon Dust Redux: Phacochoerus africanus

The above slideshow is a quick process recap of a carbon dust drawing I completed recently using a warthog skull (from my personal collection) as my model. The drawing was made specially for an event at my favorite arts and event space in Brooklyn, NY - Observatory. Since the carbon dust technique was introduced to me just this spring, at a wonderful workshop held in the classroom at Observatory, I thought it a fitting medium for the assignment.

This week, Observatory co-founder, Joanna Ebenstein, released the second in a series of short, web-based documentaries centered around her work as a passionate researcher, curator, and collector of "curious collections" - you can watch this little gem on her blog, Morbid Anatomy. Below, an African Warthog (Phacochoerus africanus) making haste to somewhere important (look at that wee tail straight up in the air!). Compared to other African game, warthogs may be diminutive omnivores, but that tusky snout is backed up by a tenacious attitude, and wise predators learn not to make light of that. 

I Heart the MCZ Week (day 7): Farewell to the Beasts

After seven pretty fantastic days full of complete MCZ indulgence, my week of natural history museum love is finally at it's end. My last sketches were made in my favorite room - the great hall of mammals - in front of some of my favorite beasts - horned ungulates: a downy Mountain Goat, a sweet-faced Takin (also known as a gnu goat), and a great Gaur (below). End of an inspiring project? Unfortunately so... Best ever way to start a brand new week? Most definitely: Best. Ever. And to anyone currently in the Boston area, or planning a visit - do yourself a favor and open up an afternoon in your schedule for a visit to the MCZ - it'll blow your mind... I promise. (while you're there, wave a little kiss to the unguates for me...)

I Heart the MCZ Week (day 2): Ungulates

I can't very well devote a whole week to loving a natural history museum and not give a special shout out to the ungulates... my heart and soul. The mammal halls will always be my default location upon any visit, but there's just something about hooves... from 20ft tall giraffes, to dainty duikers and gazelles - the grazers and the gallopers have me rapt from the tips of their pricked ears to the soles of their even or odd-toed feet (horns and antlers are cause for additional delight). Today's visit had me parked in front of the bovids, where a young Mountain Anoa stood dwarfed by specimens of Guar, Yak, and American Bison (see drawing at bottom of post). The Hartebeest above was sketched this past Sunday... I will do my best tomorrow to explore a different corner of the exhibits, though I'll tell you right now, it won't be easy. Ever and always, I heart ungulates...

Smitten (Rangifer tarandus)

This has been one freight train of a week... I did do my best to keep passengers limited to puppies, rainbows, and an abundance of awesome - and great joy of joys, this magnificent beast joined the party. Apparently "caribou" is just a North American term for "reindeer" (I'm desperate for a little taxonomic history on this), but to me, he's decidedly not a Rudolf, so I'm sticking with Boo. And I'm in love. I want to stare at him all day long, interrupted only by stroking his super-soft nose. After years of collecting skulls, bones, feathers, shells, and other assorted natural objects, this shoulder mount is my first purchase of the taxidermied variety... no surprise, I'm hooked. Now, everybody putcha glasses up - cheers to the freakin weekend!

Tall Blonde, Beau & the Beauty of Ossicones

You know you've made fast friends with zookeepers when you get invited to have lunch with a giraffe. My date was with a tall, nobby-kneed male named Beau, and while he smelled surprisingly awful (male giraffes are sometimes known as "stink bulls"...), he was lovely company, and had a surprisingly gentle mouth - unlike so many horses and dogs I've known who seem to like the taste of fingers along with their treats... Beau is a Masai giraffe (Giraffa camelopardalis tippelskirchi) - the tallest of the giraffe subspecies, and distinguished by ragged-edged spots that resemble impossible puzzle pieces.

Giraffes are pretty magical - so wonderfuly ungainly, and all at once lumbering and graceful. Beau was eager to saunter toward the feeding platform to receive our vegetable offerings, but as soon as he spotted the Zoo veterinarian (one of my guides), he side-stepped away in avoidance and assumed a wary, watchful stare with his enormous, thickly-lashed eyes. I imagined that startling a giraffe might easily lead to it's nervous system firing a charge that would betry it's own cumbersome legs... but watching this handsome, stilted giant perform the most fluid nervous pace, I could see that his ambulation - awkward as it was - could be trusted not to fail him under stress.
 

In admiring Beau's great long face, you'll notice how properly lumpy his forehead is, especially over and around his eyes. While periodically holding out handfulls of cubed butternut squash, the keeper explained that male giraffes develop these bumps as they age - a sort of skeletal scar tissue, the result of head-butting and "necking" other male giraffes (in what might be the most ridiculously awkward combat you've ever seen). Males naturally grow larger horns than females, though all of their crashing about wears the tufted fur - that so distinctively tops the apexes of lady giraffe horns - right down to the smooth hide (and yes, this is a reliable method for distinguishing gender). My anatomy interest peaked, I made time for an afternoon visit to Harvard's Museum of Comparative Zoology so I could get a better look at what all of these morphological differences looked like from the inside.

Examining bones and skeletons never fails to thrill me, and exploring comparisons between specimens (of different species, gender, or just age) is extra exciting. From the robust reserach archive of the MCZ I was able to find 2 lovely giraffe skulls - one adult female, and one adult male. Both were collected around the turn of the century and didn't have subspecies classification (Masai, reticulated, etc) listed, but their form revealed everything I was hoping to see regardless. Check out these beauties:
 

Above (clockwise from top left): the adult female skull, full front view; the adult female from 3/4 behind; the adult male skull from straight behind; and the male's forehead over the orbit of the left eye. (photos taken at the Harvard MCZ)

Lifting up each skull revealed the first dramatic gender difference - without a scale, my estimates put the female skull around 8-10lbs, but the male skull was probably about 25lbs (the kind of weight you cradle with both arms, as opposed to just "picking up"). The male skull felt SOLID, and understandably so - from the animation below, check out where the bulk of the bone mass lies: where the female's horns look like they were pinched out as a diminutive sculptural afterthought, the male sports 2 substantial columns of bone that no amount of battering could break off. His third, central horn is also decidedly horn-like, compared to the gentle knoll on the forehead of the female. It certainly isn't uncommon for ruminant ungulates to have sexually dimorphic heads (horns and antlers are much more commonly found in males of many species, and not females) and in this case, all that bone-weight in the male's skull gives it an advantage in the physics of a fight - since males spar by swinging their great heads at each other, a heavier skull would increase the force of a blow, and make for a more triumphant individual.


Beyond weight and shape, the next remarkable difference between these two skulls was in the texture of the bone (the feature that inspired this quest in the first place). In contrast to lovely lady giraffe's uniformly smooth skull surface, the top of the male's skull is built up, gnarled, pitted, and quite rough. This "extra-ossification" (gross build-up of bone formation) in male skulls generates larger, thicker horns than in females, and can lead to the development of a third (as seen in this specimen) and even 4th and 5th horn - the Rothschild subspecies is the only giraffe born with 5 horns, the extras sprouting oddly from behind each ear.

Giraffe horns are quite distinct from typical ungulate horns. Unlike the horns of cattle, goats, and antelope, in which hard keratin sheaths cover boney projections, a giraffe's horns are known as ossicones and are more like boney bumps covered direclty by furred skin (the term ossicones refers to their development as ossified cartilage). Proper horns start to grow from "buds" on the forehead of a baby cow, kid, or lamb, after birth, but giraffe calves are born with tiny ossicones already present. Not yet fully fused to the skull, these cartilaginous nubbins fold back when the baby makes it's passage through the birth canal, eventually standing erect and stitching themselves to the skull as the baby matures. In the female specimen above, the circular demarkation line between the ossicones and the skull is clearly visible (3/4 rear view), but the male's bone has grown so thickly that this line is obscured.

I had time after time watched the progression across the plain of the Giraffe, in their queer, inimitable, vegetative gracefulness, as if it were not a herd of animals but a family of rare, long-stemmed, speckled gigantic flowers slowly advancing.
~ Isak Dinesen, Out of Africa

I have posted many more of my giraffe skull photos from the MCZ into a flickr album. And if you're curious about the slightly comical act of giraffe necking, youtube this & that. Did you know there is a constellation called Camelopardalis? There is. Read a nifty discussion on the history of this celestial feature, and a bit of etymology on the giraffe's species name here. And why is their neck so long anyway? Wouldn't we all like to know! If you'd like to see/read more about the giraffe's only living relative, check out this blog entry I posted last year on the elusive, charismatic okapi. And finally, I can't post on giraffes and not link to something like this (because the internet exists in large part to simply spread cuteness around the universe).

Many thanks to my great friends at the Franklin Park Zoo, for introducing me to Beau, and the Harvard Museum of Comparative Zoology, for allowing me to spend some QT with their exceptional collections.

Oxenglow at the AMNH

Had a few lovely hours to visit with the dioramas at the AMNH this week. I would so happily pitch a tent and camp out for a while in the glow of these stunning windows into the animal world (providing I could mute all the squealing children passing through) - it is, bar none, one of my favorite places in the world. Maybe I'm just showing my age, but I'll take the dramatic quietude of masterfully crafted scenes like this over demandingly layered multi-media exhibits any day. Above, a pair of Gaur - Indian bison - the largest, and possibly most spectacular of the wild bovids. Below, a Sable Antelope mount, Pronghorn skull, and 2 more dioramas featuring Bighorn Sheep and Alaskan Moose.

Return, from the Land of Merino

After an incredible 2 weeks on the other side of the world, I am finally back on the East Coast again - a little worn out, but thoroughly inspired. New Zealand. Is. Amazing. Travels began in the North Island's metropolis of Auckland, rippled out to a number of destinations within a half day's drive of the city, and then hopped to Queenstown on the South Island, where more road-tripping brought me to epic Milford Sound, the grand Mt Cook, and some curious little towns in between. While it's winter in the southern hemisphere, New Zealand is experiencing a sadly snowless start to the season this year - a mighty bummer to all who flocked to the South Island to ski last month, but an unexpected benefit for me, since taking the place of snow-laden storm clouds were brilliant clear skies, warmer than usual temps, and open (or at least much more easily traversed) hiking trails in areas that would normally be snowbound.

Best of all, I was able this trip to do what I couldn't really manage on my last trip to NZ - closely explore the country's animals: from the now symbolic domestic sheep, to the astonishingly unique endemic birds (most of them poster species for the wonders of island biogeography), to the invasive introduced mammals that are threatening so many irreplaceable native species... I was fortunate to be traveling with a like-minded naturalist, so, in addition to stopping freely for roadside bird and critter ID, we enthusiastically made time for an agriculture show, the Auckland zoo, a wildlife sanctuary, and a number of dumpsters at the base of Mt Cook - a favorite hangout for the world's only alpine parrot (and New Zealand's most famous wild pest) - the charmingly devious Kea. Naturally, my sketchbook followed suit.
 

I'm going to be posting a series of entries from my trip in the next week or two - to start things off, the photo and drawing above come from the Rotorua Agrodome (North Island) - it's like a county fair set on repeat, with daily sheep shearing and herding demos, cow-milking, lambs and goat kids to snuggle, and an impressive breed pageant featuring New Zealand's 19 most popularly farmed sheep types. The main attraction/performance culminates with two wildly excited and barking sheep dogs running laps over the backs of the aforementioned 19 sheep, each canine finally settling - loudly - onto the wooly haunches of one poor beast (who is so obviously bored with the whole spectacle at this point in his career that his expression looks more like that of an animal with an annoyingly ill fitting collar than the anticipated fright of a defenseless prey animal literally wearing it's worst natural enemy). I would imagine this kind of attraction may not delight every tourist, but as anyone who knows me well can imagine... I was seriously riveted.

Sketchbook: Creatures from the Bronx

One year ago this month I spent a day with the fine creatures of the Bronx Zoo on a short trip to NYC. Above: some sort of hornbill, and a little ibex. I really like the ibex exhibit at the Bronx - it's landscaped into a spacious, grassy hillside, surrounded by brushy trees, and complete with rocky outcrops for the sure-footed little goats to trounce about on. Most fun is the mixed company - sharing the enclosure with the ibex is a small group of geladas. Old world monkeys that share the same dynamic social structures and ferocious smiles common to their closely related baboon cousins, geladas are stunning, flamboyantly furred primates that look like they'd be right at home if there were ever a Mardi-Gras parade over the Ethiopian highlands.

Below: an exceedingly patient dromedary camel named Rosie, who had been enlisted to give rides in the Zoo's barnyard (for some reason I imagine most camels as exceedingly patient, though I say this never having spent much time with one personally, nor in any way attempted to test those large, gentle, doe-eyes...). And lastly, a saddlebilled stork, "sitting" rather awkwardly.

I Wanted to Write You a Letter, My Love

I wanted to write you a letter

my love,

a letter that would be brought to you by the passing wind

a letter that the cashews and coffee trees

the hyenas and buffaloes

the alligators and grayling

could understand

so that if the wind should lose it on the way

the beasts and plants

with pity for our sharp suffering

from song to song

lament to lament

gabble to gabble

would bring you pure and hot

the burning words

the sorrowful words of the letter

I wanted to write to you my love…
I wanted to write you a letter…

~ Antonio Jacinto, excerpt 'Letter from a Contract Worker'
 

Open Wide

It's hard to believe that all of a hippo's grand dentition fits neatly up into its albeit fat head, but it does. Those immense, curved lower canines actually tuck right into pockets between the skull and the outside of it's muzzle, making the spectacle of multi-directional enamel shown above (a yawning pygmy hippo) visible only when the mouth is agape. Hippos use their slightly crazy front teeth (incisors and canines) primarily for posturing and battling with each other, though they do have 20 some-odd premolars and molars in the back that are used for grinding up their grass-based diet. And just like the tusks (modified teeth protruding out of the mouth/head) of mammals such as elephants, walruses, wild boars, and narwhals, hippo canines continue to grow throughout the animal's life, and, on account of their size and consequent commercial value, have historically been a sought after source of ivory (the term for dentine - the material just under the enamel, or "bark", of mammalian teeth/tusks). The fact that hippo canines and incisors do not extend outside of the mouth prevents them from falling into the traditional category of tusks, though in all other ways, they fit the bill.

Humans have harvested ivory and prized it's qualities as a lustrous carving material for thousands of years. The Inuit are known for their scrimshaws using whale and walrus teeth; peoples in India, China, and throughout the Far East used the tusks of Indian (and African) elephants to make everything from simple buttons to impossibly ornate artworks; and cultures the world over have consistently maintained a taste for the heavily traded (up until the CITES agreement of 1975) "white gold" of African elephants - to the tragic detriment of the species. Today the word "ivory" is largely synonymous with elephants - purists often refer to it as "true" ivory to distinguish it from any other animal ivory; rarely, if ever, does one think of the ivory of the humble hippo as being much of a commodity - despite the fact that it has historically come in second to elephant ivory in quantity of use, and was once considered one of the most desirable materials for the fashioning and development of a very common prosthesis - the denture.

The first dental bridges (precursors to dentures) were created by the Etruscans as far back as 500BC - they used simple but very effective designs consisting of loops of gold, connected to natural human teeth, to fill gaps in a patient's smile. Later civilizations experimented with other materials like wood, metals, bone, and ivory, though false teeth were more of a rarity than a norm right up until the 18th century, when a period of rampant tooth loss extended throughout Europe, and across the pond in North America, due to disease, poor diet and dental hygiene, and even toxic medical treatments that deteriorated tooth enamel. In the 1700s, facilitated by new fabrication techniques, and spurred by great demand (via large populations of people with agonizing and constant tooth pain, gummy lisps, and horrid breath) dentistry as a practice finally came into it's own, and among other advancements, the concept of "dentures" was born. Half dentures commonly just replaced lower teeth (using gravity to keep the base in place), but full dentures consisted of complete upper and lower teeth sets, joined by wire and spring hinges; they combined fine craftsmanship with technical detail, to the extent that many of the "dentists" that created them had previous experience as watchmakers or... ivory-turners. Designs varied widely, were constantly upgraded, and utilized a variety of mediums, though by far one of the most consistently used materials was ivory. As a solidly carved unit, individually fashioned teeth, or just the base to which other, often human*, replacement teeth were affixed, ivory proved an exceedingly popular choice for dentures - though not all ivories are created equal, and in this case, the humble hippo had an advantage.

 *Just where were all those human replacement teeth coming from? Cadavers, executed criminals, and surprising numbers of Waterloo teeth.


(Above, clockwise from top left: mammoth (left) and elephant (right) ivories showing distinctive Schreger lines (from the U.S. Fish and Wildlife Service Forensics Lab website, which contains many more images of ivory diagnostics); a cross-section of fossilized walrus tusk, making both dentine types clearly visible; and a pair of dice made of mammoth ivory, clearly showing Schreger lines.)

The chemical makeup of ivory, the substance of dentine, is consistent across species, though density and growth patterns resulting in structural differences are unique from walruses, to warthogs - even between elephants and their extinct siblings, the mammoths and mastodons. For example: walrus ivory is the only ivory to contain two distinct forms of dentine - a smooth outer layer, inside which is a mottled texture resembling rice pudding; narwhal ivory is entirely hollow and it's exterior striped with gently twisting vertical lines; cross-sectioned elephant ivory is marked by what are known as Schreger lines (a naturally occurring moire pattern, also known as "engine turning"); and hippo ivory? Hippos just happen to have some of the hardest, smoothest, most evenly textured and bright ivory of them all - more so even than that of the beloved elephant. Hippo ivory is also more resistant to staining and decay than elephant ivory - a critical trait when considering the bacterial challenges inside of a human mouth. An extremely dense form of dentine, surrounded by unusually tough enamel (tough enough to produce sparks from a bandsaw), hippo ivory is also a challenge to carve, so while it made a fitting match for denture modeling, it did not have the same broad appeal for artists that other, more gently worked ivories cultivated. 

It has recently been discovered that the most storied set of dentures in all of history - George Washington's famous "wooden teeth" - were in fact not made of wood at all, but (in large part) hippo ivory! As finely crafted as they were, dentures of the mid to late 18th century were still archaic by modern standards and their somewhat clumsy fit often required regular tune-ups, repairs (especially to the fine wire or thread that connected tops and bottoms), or total replacement; Washington had at least four sets of false teeth, of varying materials, and he frequently contacted his dentists for assistance with adjustment - even going so far as to request small files so that he could work on them himself. By the time he was inaugurated in 1789, Washington had but one remaining live tooth - the last holdout served as an anchor for a rather beautiful, hand-inscribed, hippo ivory and human teeth denture, crafted by a New York dentist named John Greenwood. When that last tooth fell out, Greenwood had it preserved in a gold and glass charm that he kept on a watch fob of mixed relics and valuable trinkets. And where Washington's tooth - that of one of the most venerated figures in American history - left a vacancy when it migrated to the status of an accessory, alongside gold buttons and carved antler seals, a little piece of a river horse took up it's place and honorable task inside the first president's mouth.


(Above, clockwise from top left: an illustration of how hippo ivory is transformed into dentures {from the BDA website}; an elaborate bottom denture made for president George Washington by dentist John Greenwood in 1789 - human teeth are set into hippo ivory, and clearly inscribed, "Great Washington's Teeth" - notice the circular hole at far right, where Washington's last remaining tooth formed the anchor for the denture {denture on display at Historic Mount Vernon}; a maxillary (top) denture carved entirely of hippo ivory, c. 1760; and a full set of ivory/human teeth dentures, top and bottom connected by wire hinges {also from the BDA})