Slater Museum: Featured Creature - 1 Feb 2013

Mammal Bacula (penis bones)

Yup, believe it or not, about 80% of mammal species possess these odd osseous objects. Everything from the tiny shrew to the epically-proportioned walrus - bacula are one of the greatest mysteries of Mammalia. As you can see here, these bones show a massive amount of variation. In the top four images, we can see how greatly the size and shape of bacula vary in the Ringed and Bearded Seals. Some animals, such as the massive, 1700kg Walrus have equally massive members, while the similarly sized, 3000kg Elephant Seals have bacula less than half the size of the Walrus’s.

The best part of all this variation is that we have no idea why it exists. Perhaps more interestingly, we don’t even know why bacula exist in the first place. Many theories exist describing the evolutionary function and significance of the baculum and its variation, but none appear to carry any more weight than another. Some have suggested that arctic/antarctic species are more likely to have large bacula than temperate species in order to ensure maximum performance during the sometimes-rare sexual encounters of the brief polar summer. This hypothesis holds-true for species such as the Polar Bear, Arctic Foxes, and some seal species, however there are just as many exceptions (other seals, sea lions, Musk Ox). Some have hypothesized that marine/aquatic mammals would require large penis bones to ensure maximum penetration during aquatic copulation, however Cetaceans (whales and dolphins) lack bacula entirely. Others have tried to draw correlations between bacula size and copulation duration. Once again, there appear to be more exceptions to this hypothesis than conformers.

Some scientists have attempted to learn more about the purpose of the bacula by studying it absence rather than its prevalence. Half of the bats, for example, lack bacula entirely, while others - often members of the same genus - possess them. This phenomenon appears to be linked to sociality in the order. In the Great Apes, humans are a unique outlier, as they are the only species lacking a baculum. Our closest relatives, the chimpanzees, possess rather tiny bacula, but possess them nonetheless. Biblical evolutionary genetics scholars have theorized that the “rib” of Adam that God used to create Eve was more likely his baculum. According to scholars, ancient Hebrew lacked a word for the penis bone, but were nonetheless aware of its existence. Upon noting that human males did not possess these bones, ancient Man might have hypothesized that its absence was due to divine intervention. There are a few scholarly papers on the topic too, if you’re interested.

I could write about bacula for days - the myriad of theories, the variation, its evolution, so much SCIENCE!!! - but I’ll spare you, dear reader, for now. In the photos above, I have presented you with a brief display of the baculum’s variation. From left to right (and bottom to top), Steller’s Sea Lion (Eumetopias jubatus), Harbor Seal (Phoca vitulina), Bearded Seal (Erignathus barbatus), California Sea Lion (Zalophus californianus), Ringed Seal (Pusa hispida), Mountain Beaver (Aplodontia rufa), Deer Mouse (Peromyscus maniculatus), Olympic Marmot (Marmota olympus), Pocket Gopher (Thomomys sp.), Ermine (Mustela erminea olympica), Long-tailed Weasel (Mustela frenata), Mink (Mustela vison), River Otter (Lutra canadensis), Badger (Taxidea taxus), Red Wolf (Canis rufus), Coyote (Canis latrans), Arctic Fox (Alopex lagopus), Kit Fox (Vulpes macrotis), Black Bear (Ursus americanus), Bobcat (Lynx rufus), Cougar (Puma concolor) and the big one on the top is a Walrus (Odobenus rosmarus) which has the largest baculum in the world (both in actual size, and in relation to body-size).

To learn more about the mammal baculum click here.

To learn more about Project Chariot (the military operation that is associated with the collection of most of these bacula) click here.

Congrats to mulishmusings to be the first to correctly identify these odd osseous objects!

Stay tuned for next week’s fantastic Featured Creature!

Ring-necked Pheasant (Phasianus colchicus) Phasianidae

No Data Available
Specimen courtesy of the Slater Museum
Photo by Robert Niese

Pheasants are native to Asia, but they have been introduced by European hunters to nearly every continent as a game bird. Here in North America, they have done particularly well and stable populations can be found throughout the plains and northern states and Canada. In spite of being considered a pest in much of their range, the males have strikingly ornate plumage and they are loved by millions (they even have their own advocacy organization!). 

I Spy…

I spy two budgies, a goldfinch, three pennies, a bat,
a tarantula, five warblers, and the skull of a woodrat;

two bacula, an eraser, a cardinal’s wing,
a bobby pin, a bushtit, and some red and white string;

four pistachios, a snipe tail, a magnifying glass, five tacks,
a paperclip chain, a sea urchin, and a pencil that is black;

a chipmunk, two hummingbird nests, two eggs that are blue,
fifteen mammal skulls, two kinglets, and a murre egg too!


See more photos here: Slater Museum of Natural History - PSM

Buy a print of this image on my Society 6 page or a full-sized canvas at the Naturalist Mercantile here in Missoula!


Slater Museum: Featured Creature - 8 March 2013

Sunda Pangolin (Manis javanica)

Top Image: from left to right, Sunda Pangolin, Nine-banded Armadillo, Northern Tamandua (an anteater)

The pangolin is not at all related to the armadillos and anteaters (which are in the superorder Xenartha), but when mammalogists first placed them in the order Edentata (along with the anteaters, armadillos, and sloths) the association seemed quite obvious. I mean, c'mon - they have the armored bodies of the armadillos, long snouts with sticky tongues like the anteaters, a reduced lower mandible and simplified teeth (or none at all) just like the rest of the Edentates - there’s no way they’re NOT related, right?

It wasn’t until scientists did DNA analyses on these animals that they realized the pangolins are, in fact, a completely separate order. Can you guess what they’re more closely related to?

Cats and dogs.

That’s right, the pangolins are a basal Carnivore.

This is a remarkable example of convergent evolution, where two unrelated species - the pangolin and anteater - have evolved similar characteristics (no teeth, long sticky tongue, huge claws, long narrow skull, etc.) due to the shared function of these traits (for digging and eating termites and/or ants), rather than shared ancestry (pangolins are more closely related to cats and dogs).

See more pictures of our pangolin specimens here.


Taxidermy Nerd

Back in my days as an undergraduate, I was part of an eccentric bunch of scientists, artists, and writers responsible for producing one of the most fantastic pieces of scientific journalism ever conceived - the Elements Science Magazine of the University of Puget Sound. The brainchild of super-nerdy bio and chem majors, Elements has now become a University sponsored medium and is a highly anticipated campus-wide publication. Elements seamlessly blends science, culture, and art, presenting readers with a myriad of interesting, engaging, and easily-comprehensible articles full of both cutting-edge and silly science.

We also pioneered the Cosmo Nerd spread inspired, of course, by stereotypically laughable Cosmopolitan Magazine covers.

Taxidermy Nerd is, by far, my favorite.

We’ve also done Biology Nerd, Chemistry Nerd, Geology Nerd, Astronomy Nerd, Calculus Nerd, CompSci Nerd, Ecology Nerd, Psychology Nerd, and Mycology Nerd.

More to come…

Plate 7 –  Red-tailed Hawk: The Bien Edition

An original chromolithograph at the Slater Museum

John James Audubon, Birds of America (c. 1827)
Chromolithograph by J. Bien, Roe Lockwood and Son, New York 1860

In 1858 John James Audubon’s youngest son, John Woodhouse Audubon, undertook a new and ambitious business venture. The project was to be the first American full-sized reissue of his father’s original Birds of America printed in London (1826-1838). The publication was to cost about half the price of the original Birds of America, and was to be sold by subscription (just like the original edition). JW Audubon planned to issue the publication in 44 separate parts — each part consisting of seven sheets or pages, containing a total of 10 full-color plates.

With the advances in color printing at the time, it was decided that the plates would be produced using the very latest techniques in chromolithography. The firm of Roe Lockwood and Son of New York was hired as publisher, and Julius Bien, a pioneer in chromolithography, was contracted as the lithographer. A few years later, at the onset of the Civil War, the Audubons were cutoff from their Southern subscribers, thus halting the production of the Bien Edition and bringing financial ruin to the Audubon family.

When production ceased in 1861, only 15 parts of the 44-part series had been issued (150 of the 440 plates). It is not known exactly how many sets of the original 15 parts were printed, but current estimates are between 75-100, making Bien’s chromolithographs the rarest edition of Audubon’s Birds of America.

Come see this original Audubon chromolithograph and more at the Slater Museum’s upcoming Celebration of Art and Science on Wednesday, April 3 from 6PM to 8PM. Gallery open April 1 through April 6, from 9AM to 5PM.


Nicobar Pigeon (Caloenas nicobarica)

This week I spent five hours photographing pigeon wings at the Burke Museum of Natural History at the University of Washington. Believe it or not, there are some gorgeous pigeons out there, but the Nicobar Pigeon stood out from all the rest. I mean, check out that iridescence! Males tend to be more shiny than females. And this individual had LOTS of shiny.

These stunningly beautiful pigeons are native to most of the Indo-Australasian Archipelago from the Nicobar Islands in the west to the Solomons in the east. They feed primarily on the ground where they eat seeds, fruits, and plant buds.

Nicobar Pigeons are believed to be the closest living relatives to the extinct Didines which included the odd, flightless Dodo and Rodrigues Solitaire. Due to a lack of DNA evidence however, scientists are still not very confident in these relationships. It seems likely that most pigeons and doves in this region are relatively closely related and diverged during an Indopacific radiation event which occurred some 50 million years ago.

To learn more about the intriguing evolutionary history of these breathtaking birds, check out this link.


What’s With the White Birds?

by Dennis Paulson, Northwest Nature Notes

We become so used to seeing birds such as robins and chickadees and sparrows that we notice right away when one of them is oddly colored. The abnormal color variations that are seen in birds often are the result of mutations that involve the reduction or lack of melanin pigments. When melanin is reduced, dark feathers become paler, even whitish. When melanin is absent, feathers are pure white.

Albinism involves a complete absence of melanin and usually results in a pure white bird with red eyes. The melanin pigment that gives birds brown eyes is absent, so the red blood is visible through the transparent cornea. This mutation does not affect other pigments, so if a bird has carotenoid pigments coloring it red or yellow, that color may remain.

Leucism is different from albinism in that it may affect all pigment types, reducing their concentration to produce a paler bird or eliminating them entirely to produce a white bird. This can occur in some or all feathers, making some birds a patchwork of normal and white or whitish feathers. A bird that is white with brown eyes is leucistic.

Odd variants are typically seen in the most common birds, so even when such a mutation is rare, we see enough individuals to eventually encounter a funny-looking one. Robins that were pale overall have been reported with some regularity. Dark-eyed Juncos are often reported with scattered white feathers, even a head pattern somewhat like a chickadee; pure white ones are much rarer, perhaps in part because they are very conspicuous to predators and don’t last long! You can see why these mutations would remain rare.

Some populations of Black-capped Chickadees in the Seattle area have persistent leucistic genes, and individuals are seen year after year in a neighborhood with different combinations of whitish caps and backs and white outer tail feathers (looking a bit like a junco as they fly away). Apparently chickadees don’t have enough visual predators to eliminate these genes entirely.

Continue reading…

Bison bison from the Slater Museum of Natural History

Finally resolved to take better care of your teeth this year? Less coffee, more flossing?

Truth is, even if you take EXCELLENT care of your teeth, scientists would STILL be able to tell what you’ve been eating (or at least its trophic level/brand of carbon fixation). How?

Stable isotope analysis, of course!

Isotope composition in mammalian enamel can tell us what something was eating long after it’s stopped chewing, and scientists frequently use this technique to investigate the ecology of fossil taxa.

But assuming you are not yet a fossil, here are some bison bicuspids to inspire you to keep brushing!

Celebrating Art and Science at the Slater Museum

Meet the Artist: Dale Thompson

Few places on earth afford better opportunities to enjoy, study, and paint wildlife than our national parks. Artist Dale Thompson’s intimate knowledge of the wilderness and its inhabitants comes from twenty years living and working as a naturalist in these spaces.

Thompson will be the first to tell you that, to paint wildlife successfully, knowledge alone is not enough. The artist must have opportunities to watch wildlife interacting and behaving normally in their natural element. From these experiences comes understanding, caring and love that will be reflected in the artwork.

Dale Thompson has been painting wildlife since retiring as Chief Naturalist for Mount Rainier National Park in 1981. Today his artwork is found in many galleries and private collections around the country.

Come see this work, and more at our Art and Science night, Wednesday April 3rd, from 6PM to 8PM in the Slater Museum of Natural History (Thompson Hall, Rm 295).