Distinctly Montana Magazine

D I S T I N C T LY M O N TA N A • FA L L 2 0 1 6 20 CAMOUFLAGE AND ARMOR Leaf-mimic katydids even rock back and both when they walk, resembling a leaf flutter- ing in the wind. Many animals use chemi- cal weapons against their predators, either synthesiz- ing toxins, or extracting (and sometimes modifying) toxins from their food. Some caterpillars ooze droplets of poison from glands near the bases of tiny barbed, needlelike hairs. TEETH AND CLAWS Carnivore teeth are small because individuals with unusu- ally large teeth performed poorly when hunting their particular prey. Teeth, claws, and claspers are sharp and lethal, but not particu- larly large or spectacular. Such are the canines of lynx: longer than the surrounding teeth and effective for separating the spinal vertebrae of hares, but not so large as to hinder over- all agility or head angle in any way, and definitely not large enough to impede the speed and coordination so essential to lynx survival. Teeth face trade-offs in shape as well as size. One tooth cannot excel at all tasks. Long and slender canines are very effective at piercing skin, muscle, or viscera, but these same teeth can snap if they strike bone. Sturdy, bladed teeth, especially if they line up precisely with other sharp and bladed teeth on the opposite jaw, are great for shearing through muscle and sinew. But the blades fracture if they are used to crush or grind bone. Alternatively, wide, solid, dome-shaped teeth are great for cracking bone to reach the nutritious marrow, but they are use- less at slicing, piercing, or puncturing. A survey of both living and extinct carni- vores shows an astonishing frequency of natural tooth breakage, with one out of every four teeth chipped, cracked, or shattered. COMPETITION Why should just one sex have weapons? And why is it (almost) always the males? We have to go back to the beginning for the answer: eggs and sperm. Both sexes offer a copy of their genome to every child, but the packages they come in are different. When sperm and egg launch a new life, it's the resources provided by the mother that first feed it. Development is expensive, and eggs provide the energy and nutrients sustaining this process. Females of all species produce larger reproductive cells than males. Eggs are bigger than sperm, and this difference is far more substantial than most of us appreciate. With the same amount of resources, males produce millions of sperm. e simple fact is that in virtually every animal species there are nowhere near enough eggs to go around. e result is competition. Claws, Teeth, Armor This book describes how animal weaponry, both offensive (claws, horns, teeth) and defensive (armor, shelter, thorns) parallels with significant (& ominous) differences human weapon- ry, both offensive (arrows, lances, swords, missiles, A-bombs) and defensive (armor, castles, spies). This excerpt is from Animal Weapons, Copyright ©2014 by Douglas J. Emlen, published by Picador. F OR AS LONG AS I CAN REMEMBER I'VE BEEN OBSESSED WITH BIG WEAPONS. One cold, mountain night in early fall — peak of the rut for elk the author and a buddy were camped in a tent. "Almost a ton of testosterone-driven rage exploded beside us not twenty feet away." Two bulls were locked in combat. "Hindquarters whirled by our tent as they quickstepped their ancient dance, oblivious to the world around them. Images from that night stay etched in my mind." As I grew and, in particular learned more about biology, I realized that "big" had little to do with abso- lute size. Extreme weapons were about proportions. Some of the most magnificent structures are borne by tiny creatures. Leaf-mimic katydid Saber tooth tiger skull Lynx skull By DOUG EMLEN

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