Long live Dr. Tatiana. Without her, what would creatures troubled by their bizarre sex lives do? You can't write to just ANYONE about this sort of problem:

"Dear Dr. Tatiana, "I'm a European praying mantis, and I've noticed I enjoy sex more if I bite my lovers' heads off first. It's because when I decapitate them, they go into the most thrilling spasms. Somehow they seem less inhibited, more urgent _ it's fabulous. Do you find this too? " - I Like 'Em Headless in Lisbon"

Imagine Dear Abby trying to cope with that one. But Dr. Tatiana, while presumably NOT a person who enjoys biting off her lovers' heads _though really, what consenting adults do in the privacy of their own home is none of my business _ is understanding. "Males of your species are boring lovers. Beheading them works wonders." Why are these guys so dull? Well, you'd be a little tentative, too, if you make "a single false step, and you're at the pearly gates with your head tucked under
your arm."

Dr. Tatiana is the alter ego of evolutionary biologist/journalist Olivia Judson, a research fellow at Imperial College in London who wants to tell everybody about the importance of natural history. Now, utter the words "evolutionary biology" to most people, and they'll gladly chew off their leg to get away from you. Not so with Dr. Tatiana. Judson has fashioned her charming, hilarious and exhaustively researched book as a series of advice columns, questions from various creatures and scientific responses to their sexual dilemmas.

It could be a one-joke book, but nature has conveniently provided astounding variety when it comes to sexual reproduction, so Judson never runs out of material. She's also not above using verbs such as "bonked" to get her message across, and she will chide the whiny. To a lion complaining that his missus wants to make love at least every half hour for four or five days: "You should be ashamed of yourself. A great big lion like you should be able to keep it up without fussing. I've heard of lions copulating 157 times in fifty-five hours with two different females. Honestly."

We've been told it's a man's world, but cheer up, ladies. That isn't true, according to Dr. Tatiana. The old scientific theory that men are promiscuous and women are chaste, well, that's bogus, and Judson happily debunks it with dozens of examples.

Judson reports that women are promiscuous because, usually, wanton females produce more _ and healthier _ children. Dr. Tatiana permits herself a taunt here: "Natural selection smiles on strumpets. Sorry, boys." Guys have it rough, biologically speaking. Girls are suckers for looks (why do you think boy peacocks have all those lovely tail feathers?) and will hang all over the guys with the best homes (if you're an orange-rumped honeyguide, for example, you'd better have a place near a lot of honeybee nests, or you're going to spend a lot of lonely nights listening to Roy Orbison).

But cheer up, guys. At least you're not banana slugs.

"In several banana slug species, individuals may get only one shot at being male, whatever their sperm count. Banana slug penises are gigantic and complex." That's the good news. Here's the bad: "During sex, the penis often gets stuck. At the end of sex, therefore, the slug or its partner gnaws off the offending phallus. It never grows back: from that point on, the slug plays only the female role." And you thought you had identity issues.

True monogamy is rare, sometimes incest is necessary, virgin birth is not a myth, and having a detachable penis is a bonus, Dr. Tatiana tells us. This is valuable information to have because "apparently," she writes, "without sex you are doomed." Anybody who's spent one too many Saturday nights alone can say amen to that.