COLUMBIA -- Baines, a 27-year-old male, long has ruled the roost in the baboon exhibit at Riverbanks Zoo.
Recently, he had to begin sharing power with a new kid on the block, a 4-year-old male named Mikale.
Next door in the lion exhibit, the new guy, Zuri, finally got to meet females Lindsey and Brynn up close after checking them out from a distance for months.
Blending new animals with old at a zoo always is a challenge. With large mammals, and their large teeth, the process can be especially worrisome for keepers.
Both of the potentially volatile situations at Riverbanks went smoothly, a testament to the skill and patience of the zoo's mammal-care staff.
"If you go too fast and put them together too quickly, you can cause harm that can't be reversed," said John Davis, Riverbanks' mammal curator. "You put a good plan together, and you do it at the animals' pace. If you hit a stumbling block, you don't proceed until you work it out."
Sometimes, it doesn't work as well. The zoo staff has been working for nearly two years to meld DeBrazza monkeys into the gorilla exhibit. They keep running into new problems.
The latest hurdle isn't the DeBrazzas fearing the gorillas or the gorillas terrorizing the DeBrazzas. It's the DeBrazzas getting along with each other, Davis said.
"There's a whole science to it," said Brandie Smith, interim director of conservation and science for the Association of Zoos and Aquariums. "Keepers aren't just making it up as they go along. There's been years of research."
No statistics have been compiled on what percentage of zoo animal groupings don't work out, but incidences of incompatibility are getting rarer, Smith said.
"If we just did this without putting any thought to it, just put the animals in with each other, it would go wrong an awful lot," she said.
The key is introducing new exhibit-mates slowly, Davis said.
Baines and his female companion, Lou, had been the only inhabitants of the baboon exhibit for several years. Mikale arrived in June along with female companions Adjoa and Imi from the North Carolina Zoo.
Males vie for dominance
Initially, the newcomers were kept away from Baines and Lou in the behind-the-scenes enclosure. The five weren't allowed on public exhibit together, with Mikale's group outside during the day and Baines and Lou at night.
One group might spot the other coming and going from the backup enclosure, but they never were close enough to touch each other. As the weeks went on and neither group showed aggression, some barriers were removed.
Eventually, they were allowed to touch each other through the bars of the enclosures. The males, especially, did a lot of posturing: facial gestures, showing their backsides, lip-smacking. "It was nonstop interaction," Davis said.
But still, no troublesome aggression from either side.
In mid-August, all five were allowed free rein of the outdoor exhibit. Mikale, who had been a suppressed younger male in a large troop in North Carolina, appears to be blossoming into a dominant male without infringing on Baines' turf, Davis said.
The five baboons still spend most of their time in groups of two and three. The males take turns acting macho. Baines might show his backside to Mikale, seemingly telling the youngster to move from his favorite perch. But later, Mikale will show some teeth at Baines, prompting the old-timer to scamper away.
"They're doing just what they're supposed to do," Davis said.
Lions get friendly
So are the lions, though their introduction took a little longer. Zuri, a 3-year-old male, hadn't been allowed contact with the zoo's two female lions since he arrived at Riverbanks 1 years ago.
Finally last week, Zuri was deemed ready, and the females were in heat. All three were released into the exhibit Thursday, and staffers held their breath.
Zuri did some playful biting of the girls, but it was part of the mating ritual. To the relief of the staff, the lions got along just fine. So fine, in fact, that it wouldn't be a shock next year if the zoo has its first full pride of lions with adults and newborn cubs since the early 1990s.