The animal keepers at the Philadelphia Zoo, a highly trained cadre exquisitely in tune with the tastes, needs, and habits of their charges, made a significant leap of faith Saturday.

They delivered Christmas presents to Sugi, Tua, and Batu.

Given that the family of Sumatran orangutans has roots in an archipelago that was originally animist and that is currently Islamist, this could be a serious cultural miscalculation.

The apes didn't seem to mind. Sugi, 12, and his mate, Tua, 19, the (pre-separation) Ashton Kutcher and Demi Moore of the neighborhood, tore off the red and green Christmas wrap and plunged their opposable thumbs into the cardboard boxes.

"Carrots!" squealed Keira Steffan, a 5-year-old visitor from Media. "His present was carrots!"

The orangutan baby, Batu, born in October and uninitiated in holiday rites, concentrated on the paper at first. Tasting it. Sticking a piece to her lower lip. Ripping off a wide strip and draping it over her head like a babushka.

Inside his gift box, Batu found her own carrot, took a bite, dropped the rest, and watched as her father unceremoniously snatched it and took off for the other side of the room, hand-over-handing it across a web of fire hoses.

"Awesome," said Gavin Zanck, watching the drama through the exhibit's two-story-high glass wall. The 7-year-old from Lansdale said he could relate. His father, Jake, steals his video games.

"Borrows," corrected Jake. "Borrows his video games. And he gets them back." Jake, a supervisor at an environmental chemical lab, and his wife, Amy, had taken their family to the zoo for the second-to-last Santa Day of the season.

Compared with the summer high season, when the zoo attracts 6,000 to 7,000 visitors a day, the place was deserted. But with Santa's visits during the last two weekends before Christmas, attendance bumps up a little.

"We're expecting about 1,000 people today," said Laura Houston, director of public programs. "This is really the best time to visit. You have the place to yourself, and as long as the temperature is around 50 degrees, the animals are out." Holiday activities continue on Sunday.

The Zancks had gone to take advantage of the low traffic. In addition to their spunky son, they were accompanied by their 6-year-old daughter, Haley, and the children's grandfather Bert Zanck.

Next stop would be the polar bear exhibit, where Jake hoped to finally see one get into the water. "I've been waiting 25 years. They never get in."

Part of Houston's job was to fetch three whole herring, with eyes and tails intact, from a refrigerator in the bear exhibit house, and take them to Santa, who was at that very moment leading a parade to the polar bears.

Her timing was impeccable. She made her way through the crowd of parents, strollers, toddlers, and the Zanck clan and handed the fish, wrapped in soggy paper, to the man in the red suit. Santa's beard and mustache dangled from his face in a manner reminiscent of Batu's wrapping paper, but his authenticity remained uncontested.

"Oh look!" Annette Reed, a professor of religious studies from the University of Pennsylvania, said to her 2-year-old son, Kunkun. "Santa has dead fish!!"

"Use your good throwing arm!" someone cried out as Santa prepared to pitch his first herring.

"Merry Christmas!" he said, launching the fish over the glass enclosure and into the crystal-clear pool.

One of the two polar bears, Klondike, watched it splash down and fall to the bottom. Dignified and aloof, she watched the second and third sail into view and hit the water. For a moment, she sniffed the air and considered diving in.

"C'mon! Jump!" yelled a kid. (Or perhaps Jake Zanck.)

Klondike, however, was not in the mood.

The crowd waited five, 10 minutes, then dispersed.

Later on, they'd find more satisfaction watching the pumas, African wild dogs, and lions open their gifts, because the animal keepers scent the boxes.

Each species has its preference, Houston said. "Pumas like Grey Flannel. African wild dogs like Chanel No. 5. And the lions? The lions like lavender."

Seriously.

Santa headed to the Treehouse to take requests. Daniyah Stills-Collins, a 5-year-old from Southwest Philadelphia, had worn camo reindeer antlers for the occasion.

She asked Santa for a doll baby and a doll baby car.

Her sister, Ty-Janique, 7, asked for a doll baby with food, a doll baby stroller, and doll baby diapers to change.

"They cost a lot of money!" Ty-Janique noted.

Santa could not bring himself to dampen the Christmas spirit with dead-herring reality by even suggesting the dolls might not be under their tree. "Everybody has the ability to dream," he said after the girls left his velveteen couch. "The sky is the limit for dreaming. And Christmas morning is so filled with an inherent joy, there is so much love around, they can forget about their disappointment in a gift that isn't there."

Contact staff writer Melissa Dribben at 215-854-2590 or mdribben@phillynews.com.