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Nature Watch: Everything from Armadillos to Zebra Butterflies

Animal Mealtime: Slugs, Grubs, and a Side of Poison Ivy

Taken as a whole, the animals of our world eat just about every conceivable thing imaginable, from juicy berries and fresh-caught fish to the poisonous, the slimy, the stinging, and the prickly. Here we take a look at the dining habits of wildlife, including what foods our birds and mammals eat, where they store their food, and what they do to prevent other animals from taking and eating it.

Picky Eaters
Some animals will eat a wide variety of foods, while others are specialists, concentrating on one or two items. In an extreme example of specialization, the teddy-bear-like Koala of Australia eats, exclusively, the leaves of certain kinds of eucalyptus trees and eats them only at certain seasons when the trees are producing specific oils. Pandas are specialists too, confining their diet to bamboo. Arctic Foxes are so dependent upon lemmings for food that the two species follow cyclical variations in population, the fox population increasing or decreasing a year after the lemming population does so.

A Matter of Taste
Some animals eat the same foods as humans, such as fish, fruits, and mushrooms. Birds eat blueberries, raspberries, and, if they can get to them, all manner of nuts. Chipmunks eat pine nuts, coveted by human cooks as an ingredient in pesto sauce. It is said that native peoples of the Northeast learned to harvest maple sap by watching squirrels. Red Squirrels harvest sugar by biting into a maple's surface, letting the sap ooze out, and returning when the water in the sap (which when fresh is only 2 percent sugar) has evaporated and the sugar content is about 55 percent.

But many animals consume items that most of us wouldn't think to put into our mouths. Leatherback sea turtles eat mainly jellyfish; backward-projecting spines in the turtle's mouth and throat help keep its slimy prey from slipping away. Pallid Bats eat scorpions, and Fishers (mink-like creatures) eat porcupines. Red Squirrels eat Amanita mushrooms, some of North America's deadliest fungi (to humans). Countless species eat grubs, earthworms, and carrion. Least Shrews will enter a beehive -- to dine. Many birds, including the Wild Turkey, routinely eat poison ivy berries, and deer and other mammals browse on the very leaves that cause susceptible humans so much misery.

Food Storage
Humans have grocery stores, pantries, and refrigerators, but animals have to be more creative with their food collection and storage methods. Some small mammals simply store food in underground burrows. The Yellow-pine Chipmunk stuffs its cheek pouches with food and carries it to its subterranean cache. One such cache was inventoried and found to contain nearly 68,000 items, including more than a dozen different kinds of seeds and a partially eaten bumblebee. One Eastern Chipmunk was observed collecting a bushel's-worth of chestnuts, hickory nuts, and corn kernels over three days. A Harris's Antelope Squirrel was found carrying 44 mesquite beans in its cheeks. Southern Flying Squirrels may store up to 15,000 nuts in a season.

An individual Eastern Gray Squirrel spends the late summer and fall picking and burying hundreds of acorns and nuts. It buries each nut individually, digging the hole and then tamping the soil down carefully to hide the nut from others. Studies have shown that these squirrels recover about 85 percent of the nuts they bury, and that they probably find them by scent, rather than memory. Many of the remaining nuts germinate and eventually grow into trees.

Foiling the Competition
Acorn Woodpeckers drill holes in trees and fence posts and then wedge acorns and nuts in, too tightly for a squirrel or other competitor to pull out. Loggerhead Shrikes impale their prey (smaller birds, mice, or insects) on thorns or barbed wire, and often leave it there to save for later. Grizzly Bears store the remains of large kills such as an Elk or Moose in a shallow depression covered with branches, dirt, and leaf litter, returning to the cache until its meal has been consumed. Mountain Lions, wolves, and foxes will hide their uneaten kills for later consumption as well. The Wolverine doesn't waste much time hiding its cached food, it simply sprays it with a foul-smelling musk to keep others away.

You Are What You Eat
In some cases the cliche is true. Marine creature called sea slugs or nudibranchs feed on sea anemones and their kin, and incorporate the anemones' protective stinging cells into their own bodies, discharging them into the mouth of any unlucky predator that comes along. Hawksbill sea turtles eat toxic sponges, which in turn can make the turtle's flesh toxic. There doesn't seem to be any danger of the toxin in poison ivy being retained in the flesh of a turkey that has dined on it, and then passed to those who eat the turkey. However, those of us who eat Thanksgiving turkeys might consider this: Some native American peoples truly believed that you are what you eat, and didn't eat turkey for fear of inheriting qualities they perceived in the species, including cowardice and stupidity. There's something to think about during your post-feast stupor!

 

 

 

 

 

2007 eNature.com