BROOKFIELD — The Humboldt penguin population in North American zoos accredited by the Association of Zoos and Aquariums is increasing thanks to efforts by animal care staff at the Chicago Zoological Society’s Brookfield Zoo, Columbus Zoo and Milwaukee County Zoo, and more importantly, by some foster penguin parents.
Brookfield Zoo agreed to take two Humboldt penguin eggs — one that has hatched and one that has yet to hatch — from Columbus Zoo and Milwaukee County Zoo, respectively.
In early January, a penguin at Columbus Zoo laid an egg. However, during the Arctic blast that swept through Ohio, the penguin and her mate had difficulties incubating it. The coordinator of the Association of Zoos and Aquariums’ Humboldt Penguin Species Survival Plan recommended that it was in the best interest of the overall zoo population to transfer the egg to Brookfield Zoo, so that a foster pair could continue the incubation process and rear the chick. (The pair at Columbus Zoo subsequently bred again and was successful in incubating a second clutch.)
At Brookfield Zoo, Salsa and Ceviche, 10-year-old Humboldt penguins who have successfully raised chicks in the past, were in the process of incubating an egg, but it was infertile. To alleviate unnecessary stress on Salsa, staff allowed her to complete the natural incubation cycle but pulled the infertile egg from the nestbox and replaced it with a fake egg. When the egg from Columbus Zoo arrived, the fake egg was removed and replaced with the new fertile egg. Ceviche and Salsa successfully incubated the egg.
On Feb. 20, a male chick hatched, and he is progressing very well due to attentive care from his foster parents.
Guests visiting Brookfield Zoo’s Living Coast exhibit may be able to see the Columbus Zoo chick as he peeks out from the nestbox. He is distinguishable from the adults by his dark gray plumage, which will eventually molt into to a lighter gray and white color.
When he is about 70 days old, the chick will leave the nest permanently.
At Milwaukee County Zoo, a penguin pair is currently incubating two eggs. Humboldt penguins rarely are successful at raising two chicks simultaneously. To increase the chance of both chicks surviving, one will be raised by its parents at Milwaukee, and the other will be raised by foster parents at Brookfield Zoo. A transfer date for the egg is still being determined.
“We work closely with other institutions to breed and maintain healthy, self-sustaining populations that are both genetically diverse and demographically stable for a variety of species, including Humboldt penguins,” said Tim Snyder, curator of birds for the Society. “These particular penguin pairs at Columbus Zoo and Milwaukee County Zoo are not well represented in the overall accredited North American zoo population, and so we are excited to assist in the long-term viability of the population.”
Native to the coasts of Peru and Chile in South America, Humboldt penguins are considered one of the world’s most endangered penguin species and are listed as vulnerable by IUCN-The World Conservation Union. Population numbers once totaled an estimated hundreds of thousands of animals during the 1800s but are now estimated to be less than 50,000. One of the causes of their decline is overharvesting of guano, their preferred nesting habitat. More recent threats to the survival of this species involve overfishing of their prey, entanglement in fishing nets, fishing with dynamite, hunting, predation from introduced species, and human disturbance. Significant conservation efforts have been directed toward stabilizing the population.
To help in the conservation effort, Michael Adkesson, DVM, Dipl. ACZM, vice president of clinical medicine for the Chicago Zoological Society, travels annually to Punta San Juan in Peru to continue a comprehensive population health assessment project that began in 2007. The data collected help define the current health of the population and provide a baseline for continued monitoring of population health over time.
The Chicago Zoological Society, which manages Brookfield Zoo, inspires conservation leadership by connecting people with wildlife and nature.
The Chicago Zoological Society is a private nonprofit organization that operates Brookfield Zoo on land owned by the Forest Preserves of Cook County. Open every day of the year, the zoo is located off First Avenue between the Stevenson (I-55) and Eisenhower (I-290) expressways and is also accessible via the Tri-State Tollway (I-294), Metra commuter line, CTA and PACE bus service. For further information, visit www.CZS.org.