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Nature Watch: Everything from Armadillos to Zebra Butterflies

Nine-banded Armadillo
credit: Mwcolgan8

Fur Factor: A Quiz

Don't have time to take a full course in mammalogy? Well, take this test instead. It highlights attributes of different mammalian orders and families and showcases the extreme cases in some groups (the biggest, the smallest, and so on). After all, these are the only facts most people remember after the final exam.

Q. Which U.S. land mammal has the most teeth?

A. The Virginia Opossum is the record holder with fifty teeth. It also boasts the shortest gestation period (twelve to thirteen days) and the greatest amount of growth from birth to average adult weight (1/10 ounce to 12 pounds). The Virginia Opossum, by the way, is the sole North American member of the most primitive mammal group on Earth: Marsupialia.

Q. What's the smallest mammal in North America?

A. The Pygmy Shrew of southern Indiana weighs 1/16 ounce when full grown. It belongs to the order Insectivora, which contains shrews and moles and the shortest-lived mammals in the world (many species typically live less than a year).

Q. What's the largest rodent in the country?

A. No, it's not a rat but the American Beaver, which can weigh up to 86 pounds. The smallest rodent, meanwhile, is the Northern Pygmy Mouse. This species probably also sets records for being the fastest species to attain sexual maturity (twenty-eight days) and for having the highest reproductive output (nine litters in 202 days).

Q. What's the smallest carnivorous mammal in the United States?

A. The Least Weasel, which attains a maximum weight of 50 grams. Compare that figure with that of the largest member of the order Carnivora, the Alaskan subspecies of the Brown Bear, which can weigh up to 1,700 pounds.

Q. What's the only member of the order Xenarthra in the United States?

A. The Nine-banded Armadillo. Sloths and anteaters are among the other strange members of this order.

Q. What's the largest weasel in the United States?

A. Don't guess the Wolverine, which tops out at 40 pounds. The largest species weighs twice that. Give up? It's the Sea Otter.