Have You Met Charger the California Sea Lion Pup?


On June 10, nine-year-old California sea lion Josephine ("Josie" to her friends) gave birth to a male pup named Charger. After giving them some time to bond behind the scenes, both mom and pup can be seen swimming and playing at Pinniped Point in Brookfield Zoo.

Since his birth, animal care staff estimate Charger has slready nearly doubled his weight to approximately 40 pounds. He has been growing steadily due to the richness of their mothers’ milk, which is high in fat. Within the next month, staff will introduce him to a diet of fish. However, Charger will nurse for at least five to six months and may continue to do so for a year.


This is Josephine’s second pup. Her first, named Lucy was born in 2017. She still resides at Brookfield Zoo along with another 2-year-old named Taylor, who is the new pup’s half-brother. Josephine, and the sire, 16-year-old Tanner, are both wild-born and very important to the species genetic diversity in the accredited North American zoo population. Josephine, was abandoned by her mom on Pier 39 in San Francisco—a popular tourist attraction—and would not have survived without human intervention. The Chicago Zoological Society (CZS) stepped forward and offered to give her a home at Brookfield Zoo, where she was hand-reared and has resided since 2010.

In 2012, Tanner arrived at Brookfield Zoo from Shedd Aquarium, where he first received a second chance at life after NOAA Fisheries officials removed him from the wild for feeding on a federally protected endangered species of salmon in the Bonneville Dam area on the Columbia River. In order to identify him should he return to the dam to feed again on the endangered salmon, government officials gave him the distinguishing and permanent ID on his back, “C011.” Despite several attempts to relocate him to another area, Tanner continued to return to the dam.

The pairing of Josephine and Tanner was based on a recommendation from the Association of Zoos and Aquariums’ California Sea Lion Species Survival Plan (SSP). The program manages the breeding of sea lions in North American accredited zoos to maintain a healthy and self-sustaining population that is both genetically diverse and demographically stable. Mairim Martinez, a senior animal care specialist for CZS, is the coordinator of this plan and manages the studbook for the species. In these roles, she is responsible for documenting the pedigree and demographic history of each individual California sea lion at each institution and assists in making breeding recommendations. The Chicago Zoological Society is also an accredited member of the Alliance of Marine Mammal Parks and Aquariums.

Although not threatened in their natural habitat along the west coast of North America from Vancouver Island in British Columbia, to the southern tip of Baja California in Mexico, California sea lions still face challenges. Threats include entanglement in fishing gear, toxins they ingest from their prey, intentional dumping of toxic and hazardous waste, and changes in global atmosphere pressure that affects the availability of prey. Today, the 1972 Marine Mammal Protection Act protects all marine mammals, including California sea lions.

Those interested in helping care for the California sea lions at Brookfield Zoo can contribute to the Animal Adoption program. For $35, the recipient will receive the Basic Package, which includes a 5-inch x 7-inch color photograph and fact sheet about the species, a personalized adoption certificate, an Animal Adoption car decal, and an invitation to the annual Animal Adoption Evening. For further information, visit CZS.org/AnimalAdoption.

Posted: 7/16/2019 4:13:59 PM by Sean Keeley Filed under: babies, Charger, Josephine, lion, sea

CZS & Brookfield Zoo

Since the opening of Brookfield Zoo in 1934, the Chicago Zoological Society has had an international reputation for taking a cutting-edge role in animal care and conservation of the natural world. Learn more about the animals, people, and research that make up CZS here at our blog.


Subscribe to our Blogs!