Today’s post features four pairs – so similar in characteristics that most people may not know why they are different species in the natural kingdom. The information is taken from “What’s the Difference  – Suble Distinctions in Nature” – Sierra Club Knowledge Cards available through Pomegranate Communications, Inc., www.pomegranate.com. Read on to learn more…

What’s the Difference Between: An Elk and a Caribou?

In the United States, a large North American deer, the wapiti, is called an elk. Europeans call what we call an elk, a moose, the largest of the deer family.
Elk are the second largest – big males can weigh half a ton.
Caribou are third largest, with males weighing 275 to 600 pounds. Female caribou are the only female deer to have antlers.

European caribou are nown as reindeer, but are not a different species. All caribou live in the far north and have large, concave, sharp-edged hoofs that help them walk on ice, snow, and soft tundra and facilitate digging through snow for nutritious lichen. Reindeer are domesticated for milk, meat, and pulling sleds. Elk are more wild, and range farther south – as far as New Mexico and Arizona.

A Kangaroo and a Wallaby?

Kangaroos live in Australia and surrounding islands. They range from the 6-foot-tall gray kangaroo to the 9-inch-tall rat kangaroo.

Wallaby is the popular native name for medium-sized kangaroo species. The agile wallaby is the largest, averaging about 5 feet in height. Other wallabies are smaller and may be more brightly colored than larger species.

Kangaroos are plant eaters with huge hind legs and a notably muscular tail that enables them to travel up to 30 mph in a series of long jumps. Those powerful legs are also used effectively for defense. Tree kangaroos have extra-long front legs that aid them in climbing.

Kangaroos are marsupials: animals that raise their incompletely developed newborns in a pouch on the female’s belly until they can fend for themselves.

A Yam and a Sweet Potato?
Yams and sweet potatoes are NOT related!

Yams spread from South Pacific islands to many other tropical areas, including Africa, Japan, China, India, Australia, and the West Indies, where they are an important part of the diet. Some varieties produce tubers weighing up to 100 pounds. Yams have more protein than potatoes. In the United States, they’re grown commercally in south Florida. The vines are also grown for ornament as far north as New York.

The sweet potato is a member of the American morning glory family. Grown worldwide for food, it is among the most nutritious vegetables available, particularly in vitamins C and A. An acre provides about double the food value of an acre of rice. Sweet potatoes are grown in most parts of the United States where untimely frost is unlikely.

A Beetle and a Cockroach?
Beetles are Coleoptera, the largest order of insects. With more than 300,000 species, they represent about 20 percent of all animal life on Earth. Most beetles are equipped with two pairs of wings. The thick, tough, veinless front pair hinge forward out of the way of the transparent, veined rear pair used for flying. Closed, the front wings meet in a straight line down the center of the beetle’s back to protect the fight wings beneath.

Cockroaches are Orthoptera. There are about 3,500 species. The front wings are narrow and thick with visible veins. The transparent, veined rear wings unfold like fans. Folded cockroach wings meet in a crosscross, one over the other, leaving a small uncovered triangle at the front.

Beetles develop through a complete, four-stage metamorphosis. Cockroaches develop in a considerably simpler process.

Are there any ‘pairs’ out there that you would like to know the difference between? Be sure to ask!