It isn't glamorous, nothing more than a chain-link fence, a few trees, a puddle and a pile of hay bales, but to Pepe and Kotze it's a new beginning, a chance to get to know each other and maybe lay an egg or two.

"He does want to get close to her, but as you notice, she keeps moving away from him," observes Fred Beall, Franklin Park Zoo's general curator, from just outside the African wattled crane exhibit there. "We'll know when they're bonded because they'll be standing next to each other."

And Beall should know about crane-love. He's the international studbook keeper for the rare African wattled, a grey and white marsh-loving bird than can reach a majestic height of six feet. Most notably, wattleds possess wattles under their beaks as turkeys do. Wattles look a lot like droopy elongated jowls - hanging down as much as six inches - but with feathers and a warty-red skin. No one knows what purpose they serve.

Beall tracks all the wattled cranes in captivity, their family trees, and how many times they've "done it." He's the go-to guy for making wattled love matches in North America.

Of course, there's a need and a science for this sort of thing.

Only around 8,000 wattled cranes are left in the world. BirdLife International rates their status as "vulnerable" due to hydroelectric dams that have sunk wetlands and other crises in their native African habitat, which stretches across some eleven countries from Ethiopia to South Africa. And complicating matters, wattleds are downright conservative family planners.

They take the till-death-do-us-part aspect of companionship as gospel, and when they raise an egg it is strictly one-at-a-time. If there happens to be two in their 'clutch,' one is likely to get the boot from a spindly crane leg.

Strangely, Beall is positive that schoolbus-loads of children making fun of their ugly wattles will not dissuade the pair from nesting.

There are also problems with male birds that don't perform as they should, which some zookeepers attribute to their clipped wings (conception involves the male jumping up on the back of the female, balancing long enough to copulate, and then dismounting), but Beall thinks is more likely something the birds are lacking in their diet.

Artificial insemination, a last straw for other crane species, is tough with wattleds too, as males tend to shut down after their keepers try to make a collection.

"They've got their own set of problems," said Beall, "but I enjoy the challenges and I think eventually we'll figure all of this out."

Beall's job as studbook keeper involves making sure all the crane couples across North America are getting along, laying and caring for their one offspring each breeding season. But there's a bit of number crunching involved too.

"We want the birds we have in captivity to be self-sustaining, to keep a reasonable population with out having to go to take birds from the wild," said Beall in a phone interview. "The goal is to retain 90 percent of their genetic diversity for 100 years."

Beall said that in reality the accomplishment will likely amount to 90 percent for 67 years, even after careful crossbreeding keeps bringing shy birds back into the gene pool.

When a breeding pair does not cotton to each other, he recommends a trade between zoos, like swap he suggested Franklin Park Zoo make with the San Diego Wild Animal Park in California.

Kotze, Franklin Park's 12-year-old female wattled crane, wasn't getting along with the male she was formerly paired with, so the zoo swapped her mate for the San Diego Zoo's Pepe, a 27-year-old male who lost his wattles due to a previous infection, but carries valuable genes for the continuing health of the captive wattled population.

After a series "howdies" where the two birds were held close together but not allowed to touch, a gradual process of opening gates so they could mingle, and then moving the pair into their new home on neutral ground, Kotze and Pepe have started to tolerate each other. Beall hopes the new couple will breed in January or February, during the next breeding season.

"If they really like each other they will come together and display and dance, and court each other," he said. "A year or so is not uncommon."