Harbor seal at Milwaukee County Zoo dies shortly after birth of healthy pup

A few days after giving birth to a healthy pup, one of the Milwaukee County Zoo’s harbor seals died from an infection.

The male pup, who has not yet been named, is being hand-reared by zookeepers and animal care staff. He sleeps with a specially made substitute mother made from a plastic tube inside a wet suit.

Sydney was 24 years old when she died unexpectedly on June 6, the zoo announced Tuesday.

Sydney and her companion, Ringo, were the parents of five offspring in the last seven years. Her most recent pup was born on June 3.

At three days old, he weighed 24 pounds and by June 23 he had gained 13 pounds on a five-times-daily menu of milk replacer formula with a high-fat content and vitamins developed specifically for marine mammals. Finely ground fish have been gradually added to his formula.

Harbor seals usually nurse for four to six weeks.

When the pup was three weeks old, he was introduced to live fish to accustom him to seals’ natural diets. But zookeepers report that he seems more interested in playing with the fish and has not yet started eating them.

He has been introduced to 5-year-old Cossette, a female harbor seal, in an offexhibit area where he has access to a kiddie pool filled with toys and a holding pool where he can swim. His favorite toy is a red Frisbee.

He will be gradually introduced to other harbor seals at the zoo, including his 42-year-old father. And keepers will soon start his training program to teach him to respond to cues.

Sydney came to the Milwaukee County Zoo in 2005 from the Alaska Sea Life Center where she was rescued as an orphan pup in 1996. A preliminary necropsy revealed Sydney had a systemic infection that started in one area and moved to her bloodstream.

She was very smart, teaching her keepers how to be patient, calm and reliable, according to zoo officials. Known for her steadiness, Sydney helped Cossette settle into her home in Milwaukee when she arrived.

Sydney even retrieved a keeper’s dropped cellphone from the bottom of the pool in the zoo’s exhibit.

COUNTY ZOO JOEL R. MILLER / MILWAUKEE A male harbor seal pup was born at the Milwaukee County Zoo on June 3, three days before his mother, Sydney, died unexpectedly.