Wednesday, December 3, 2008

The Corpse in the Garage

“Looking askance at the black blob on the garage floor, I simply could not imagine what dark colored thing the cats could have urped-up. Standing over it, the blob resolved into a small still body, the little corpse was that of a shrew, an unlikely find in a garage-a mouse highly likely-but a shrew no. I smoothed the dark fur then picked up the sad little body turning it over inspecting the stiff and cold body the only apparent injury its poor little bloodied nose. It seemed unlikely a shrew, somewhat fossorial in habit, would voluntarily venture across such a vast plain of concrete drive only to enter a garage containing a dreaded nemesis's litter boxes. I am not sure, if it crept in injured and died or my cats did it in, but my best guess is that one of the two calicos roaming the yard caught the poor creature and was playing with it on the drive when it slipped under the garage door to escape it tormentor and died in its retreat. The idea that the pugnacious little shrew encountered my naive indoor kitties was amusing; I imagined them corned by the fearless little hunter, but I would never know for sure.


My first encounters with short-tailed shrews was in childhood when my cat, Sassafras, from somewhere beyond the barn, would catch them and then bring them to the short grass of the yard where she could easily keep track of the fleeing creatures. Sassy’s erstwhile quarry-turned-toy first was hurled to great heights then expertly pinned to the ground, but shrewdly, her prey slipped the bounds of the velvet paws squeaking and turning the miniscule gladiator fought back, clearly, she enjoyed the shrew’s tenacious fighting verve. By and by, the more durable ones she would let escape to the tall grass or those less fortunate would die from their battle wounds, but she never ate the remains she would simply nudge the corpse gently and lay her head down on her paws waiting for her playmate return to life. I always took these opportunities to inspect these mites, and despite my status as a giant, I always jumped when they lunged at me. My city-raised mother inexplicably knew that these creatures were the poisonous short - tailed shrews, and why she thought that telling me they were poisonous would make me leave them alone I do not know as it only served to pique my interest for I found them as compelling as my cat did. In the time intervening childhood and now, I learned more about these little underdogs in books, but only in my childhood yard, did I learn and come to appreciate the bravery and bravado of this miniscule predator.

As I mentioned these shrews are poisonous, which makes them mammalian curiosities. Poison is not an uncommon strategy of the hunt or defense in nature, but it is unusual in mammals. The list of mammals that produce toxins is rather short: the North American short-tailed shrews, Eurasian water shrew, solenodons, slow lorises, and male platypus.

The platypus is that down-under monotreme curiosity that looks like it is made up of one part duck and two parts beaver. In the platypuses, only the male platypus has a calcaneus spur located on its hind leg, and as the male only has the spur, it seems the spur must play a part in reproduction like males fighting.

The slow loris, a big-eyed cute primitive primate or prosimian, is found in Southeast Asia. Loris’s poison is secreted from a sebaceous gland located at the elbow and taken into its mouth by a small comb tooth that directs the toxin into bite wound or (and more interestingly) the toxin is combed through the fur of the baby possibly making it repellent to predators. A couple of interesting things about the loris’ poison is that straight from the gland other chemicals from that gland interfere with the poison but mix it with saliva and it becomes noxious and poisonous (to some degree), and the other interesting thing is the toxic protein is similar to the allergenic protein in cat dander. For those of you who are allergic to cats and feel that the cats are out to get you-well they might just be with their toxic proteins!

Solenodons are found in Cuba and the Isle of Hispaniola and are a distant relative of the shrew, and in fact, resemble the shrew, well if a shrew was crossed with a opossum. The solenodon’s second incisors are grooved thus giving the poisonous saliva a channel to flow through when the prey is bitten. The poison is produced in glands at the base of the incisors.

Shrews secrete a poison from the submaxillary saliva glands at the base of their lower incisors. The shrew does not actively inject the poison, but it flows by capillary motion and is delivered by the bite. A short-tailed shrew’s saliva contains a neurotoxin, which may aid the shrew in killing prey larger than itself, but more interestingly as a way to stock and keep a larder full of “fresh” food. Only the northern short-tailed shrews’ poison has been confirmed by an arduous chemical analysis, but it is likely the other three short-tailed shrews, the southern, Elliot’s, the Everglades, as well have injurious spit. The shrew toxin has been isolated, reproduced, and therefore patented. As it is a paralytic, it is being explored for its medical potentials like relaxing wrinkles!

“Madame, for your facial would you prefer a deadly bacterial toxin or shrew spit?” Ahhhh…the cost of beauty!

To Be Continued...

Pam Croom © 2008

1 comment:

Rurality said...

Hmm, didn't know that, about the poison! I definitely need a ruler like that. :)

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