And the lessons of "The Lion King" about the circle of life continue to apply as well.
Brookfield this week welcomed a baby gorilla. And Van Bonn took time off to help his wife deliver their first child.
Chicago's oldest animals
Cookie (Major Mitchell's cockatoo, age 80): Believed to be the oldest of his species in professional care, Cookie came to Brookfield when it opened in 1934, a 1-year-old sent from an Australian zoo. Off exhibit since 2009, he lives in a keepers' office, beneath a staff binder marked "Egg Logs." At the Brookfield Zoo, 8400 31st St., Brookfield; 708-688-8000 or czs.org
Granddad (Australian lungfish, age 80): Granddad might be older than 80. He arrived full-sized at the Shedd in 1933, three years after the aquarium opened. Even without additional years, he is the oldest living fish in any public aquarium, Shedd staffers say. At the Shedd Aquarium, 1200 S. Lake Shore Drive; 312-939-2438 or sheddaquarium.org
Maggie (Bornean orangutan, age 52): Maggie arrived at Brookfield in 1995 and is the oldest of her species at an accredited North American zoo. She still scampers up to her loft like perch to sleep. And Tuesday, she had the company of the young white-cheeked gibbon Thani as keepers tossed grapes to them. At the Brookfield Zoo.
Vicky (chimpanzee, age 50): The oldest animal at the Lincoln Park Zoo, she is well past the median life expectancy for female chimps (38.7 years). She lives with daughter Kibali, who, at 33, is no spring chicken. At the Lincoln Park Zoo, 2200 N. Cannon Drive; 312-742-2000 or lpzoo.org
Maggie (dwarf crocodile, age 47): Maggie is a very popular name, apparently, for older animals. The reptile Maggie is the second-oldest animal at the Lincoln Park Zoo, but 47 is just her minimum age, calculated from when she began living in zoos, in 1966. Maggie gave birth in her 40s, in 2007. Fun fact about crocodile management: She is kept well fed enough that she does not eat the 400 tilapia that share her enclosure. At the Lincoln Park Zoo.
Ramar (Western lowland gorilla, age 45): The third oldest western lowlands male in North American care, Ramar has fathered three since arriving at the Brookfield Zoo in 1998. He was off display for a time this week as the zoo welcomed a baby female gorilla sired by JoJo, who moved to Brookfield from Lincoln Park in 2012 for breeding purposes. At the Brookfield Zoo.
Mauyak (beluga whale, age 32): Belugas in the wild live 10 to 25 years. Mauyak, who arrived at the Shedd in 1997 from Point Defiance Zoo and Aquarium in Tacoma, Wash., has raised three calves at Shedd — including the Shedd's youngest beluga, Kimalu, born last year. Mauyak is both the oldest and the smallest adult at the aquarium, identified by gray streaks on her sides. At the Shedd Aquarium.
Aussie (polar bear, age 28): Since arriving at age 1 from an Australian zoo, Aussie has sired five. Tuesday he buried his face in a pile of lettuce and peanut butter and swam in his pool, a remarkably graceful display for a 930-pound animal. Only in his exit from the pool, navigated a little gingerly in his hindquarters, could you see his age. At the Brookfield Zoo.
Maku (Eastern black rhinoceros, age 27): Almost 10 years beyond the median black rhino life expectancy, Maku, 27, was the sire (with 8-year-old Kapuki) of the zoo's headline grabbing new black rhino, King. What else can you say about a rhinoceros? "He is also known for his love of a good wallow," zoo staff said. At the Lincoln Park Zoo.
Lurch and Bruno (cinerous vultures, ages 25 and 26): The unfortunately named Lurch (female) and Bruno (male) have been a couple for 23 years; cinerous vultures mate for life. Their chick Sophia, born in June, is already as big as her parents. At the Lincoln Park Zoo.
Anya (Amur leopard, age 23): The oldest of her species at a North American zoo, she remains active despite some infirmities and, her handlers say, is quite vocal. At the Brookfield Zoo.
Myra (African lion, age 17): Seventeen is just past the species median life expectancy of 16.8 years, but Myra has more than a 15-year tenure at Lincoln Park and has had three cubs. Not to stereotype the aged, but, zoo staffers say, "her favorite activity is napping in the northwest corner of her exhibit." At the Lincoln Park Zoo.