He stands on a grassy slope, right arm extended upward with an alfalfa treat, addressing his 4-ton companion in the tones of a tender friend.

"You're a sweetie, aren't you? You're special," Mike McClure says. And Dolly plucks the treat from his hand, curls it into her mouth and emits a guttural rumble.

That's the sound of a pachyderm purring, says McClure, the director of animal programs at the Maryland Zoo in Baltimore and an internationally known handler of elephants. Dolly, 36, is an African elephant.

It's a remarkable degree of mutual trust — and one that the trainer is sure he'd never have developed were it not for a grim-looking tool some call an instrument of torture.

The so-called bullhook, a 2-foot goad with a pointed end that elephant handlers have used for centuries to train and guide the huge creatures, has been the subject of a national debate that has had Baltimore talking since the Ringling Bros. and Barnum & Bailey circus rolled into town this week.

Elephant trainers around the world still use the tools, now commonly called guides. Animal-rights activists have complained for years that the devices are barbaric.

It's a debate that has pitted Jada Pinkett Smith, a Baltimore-born actress and spokeswoman for People for the Ethical Treatment of Animals, against MayorStephanie Rawlings-Blake. In a sharply worded statement this month, Pinkett Smith noted that, unlike people in her profession, elephants do not choose to perform. Rawlings-Blake brushed off the concerns and sided with Ringling Bros., which calls its practices humane.

The company's annual run at 1st Mariner Arena ends April 1.

"The process of training is a complex equation, one with many components. The guide is one tool in that equation," says McClure, a certified board member of the Elephant Managers Association, an international nonprofit devoted to the species' conservation and welfare. "Our detractors don't have the experience or insight to know what makes the tool important."

On Monday, even as the circus was loading six of the animals onto a specially outfitted train for Baltimore, McClure said the best way to understand his meaning is to take neither side at face value but to observe the tools in use.

At the zoo

The zoo looks different behind the scenes — all locked gates, tall fences and trailers — and when an official finally grants entrance through the proper checkpoint, McClure, slender and sun-reddened at 41, appears to greet a visitor.

He marches down a slope to the edge of the elephant enclosure, where Anna, an 8,000-pound 37-year-old — one of the zoo's five elephants — looms just across a safety barrier, gazing down through fluffy lashes.

"She has already checked you out thoroughly," he says, adding that elephants, the most intelligent creatures on four legs, can detect smells and sounds from a dozen miles away. "She approves."

He has a thought. "Anna, trunk," he says in a placid tone. She raises the appendage, allowing McClure to probe inside her mouth, where he recently cleaned out a socket after she lost a tooth.

"If we didn't train these elephants, we'd never be able to reach places like this and offer them the grooming and medical help they need," he says.

McClure got his start in the business working construction at a small South Carolina zoo. In the aftermath of Hurricane Hugo, he proved adept at wrangling escaped animals, including a 6-foot female alligator that had eluded his superiors.

He arrived in Maryland in 1995, worked with chimps, tigers, polar bears, hippos and giraffes, and took over the elephant program in 2002. He has been running it since that time.

Today he's offering commentary as two underlings — Katie Ernest, a two-year veteran, and Jon Murray, a newbie — put Anna through a few paces. For half an hour, they display an axiom basic to the field: He who uses the guide least uses it best.