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PRI's Environmental News Magazine

March Hares

Air Date: Week of March 22, 2002

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Commentator Sy Montgomery weighs in with her theory on why the month of March is a time of madness for hares.

Transcript

CURWOOD: As Lewis Carroll sat writing "Alice in Wonderland" back in 1862, he faced a dilemma. Just who should host a mad tea party? His inspiration came from the proverbial expression "mad as a March hare." It may seem an obvious choice. But, as commentator Sy Montgomery suggests, like everything in nature, there's a method in the March hare's madness.

MONTGOMERY: Quiet and shy, the hare is seldom glimpsed except at dawn and dusk here in New England. Even then, it's hard to see with a coat that varies with the season; white to camouflage it in snow, and brown the rest of the year.

It would seem that the snowshoe hare upholds all standards of lapine sanity and propriety. But come March, hares go haywire. Symptoms of insanity appear mid-month. Hares dare to dash about in full daylight. They pick fights with other hares, and engage in boxing and kicking matches, and high-speed chases.

And as the month wears on, as Alice might say, "things get curiouser and curiouser." The strangest scene takes place when male and female meet. After sniffing each other out, one hare will leap over the other. And the one in mid-air releases upon the one below a shower of urine. These airborne aerobics go on until both animals are thoroughly soaked.

And for hares, this is apparently a huge turn-on. Mating follows several times over the course of the next few hours. It's not exactly flowers and candy, folks. But, urine does contain important chemical information about potential mates, including levels of sex hormones. If you thought human courtship and child raising was complicated, hares have a lot more to deal with.

Hares produce up to four litters a year, driving a dramatic boom and bust population cycle. In the northern half of the continent, hare numbers increase up to a hundred-fold, roughly every five years, and then abruptly crash. This ten-year cycle has puzzled researchers for decades. Most astonishing is that the hare boom is synchronous across the northern 4,000 miles of its range throughout the evergreen forests of Canada.

But in more southerly climes, with more varied forests and many different predators, most experts agree the hares either do not have the same boom and bust population cycle, or the cycle is far subtler and more complex. But the picture is even more complicated. Recent research shows the hare cycle also involves subtle changes in the relationships between plants and animals, parasites and hosts, and, perhaps, even events 93 million miles away.

Among the latest findings, as growing numbers of hares begin to decimate their grassy food, plants respond by manufacturing new chemicals to make themselves less tasty. Malnourished hares are more susceptible to parasites, like stomach worms. And weakened, they fall prey more easily to predators.

And finally, new work from Canada suggests sun spot activity, a ten point six year cycle, might affect weather patterns which could control plant growth, which could affect hare numbers. So, perhaps the hare's mysterious March madness isn't so hare-brained after all, but an expression of a strategy brilliant and perfect beyond our comprehension.

[MUSIC: Magnetic Fields, "Let's Pretend We're Bunny Rabbits," 69 LOVE SONGS]

CURWOOD: Commentator Sy Montgomery is author of the new book, "Encantado: Pink Dolphin of the Amazon."

[MUSIC UNDER]

 

 

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