Polar bear cub Astra, whose name means “star” in Norwegian, plays with her mother, Suka, 8, at the Detroit Zoo.

Polar bear cub Astra, whose name means “star” in Norwegian, plays with her mother, Suka, 8, at the Detroit Zoo.

Photo provided by the Detroit Zoo

Detroit Zoo polar bear cubs enjoy first foray into outdoor habitat

By: Sarah Wojcik | Metro | Published May 12, 2021

 Astra, a 5-month-old female polar bear cub, interacts with her habitat alongside her mother, Suka, 8.

Astra, a 5-month-old female polar bear cub, interacts with her habitat alongside her mother, Suka, 8.

Photo provided by the Detroit Zoo

ROYAL OAK — Born Nov. 15 to female polar bear Suka, 8, Detroit Zoo officials report that the now 5-month-old twin female polar bear cubs are thriving and recently ventured from their indoor settings to the grassy area of the Arctic Ring of Life habitat.

In an unusual turn of events, Astra — a Norwegian name meaning “star” — is being reared by Suka, and Laerke — a Danish name meaning “lark” — is being reared by zoo staff after she required additional veterinary attention the day after her birth.

The pair are the first of their species to be born and successfully raised at the Detroit Zoo since 2004. While Suka gave birth to cubs in 2018 and 2019, none survived beyond a few days.

Laerka’s weight increased from 1.2 pounds to 11.3 pounds with around-the-clock care and bottle feeding, and both cubs successfully hit developmental milestones, such as opening their eyes, growing teeth and beginning to walk. The young bears have mostly graduated from liquids to a solid diet of meat, fish, produce and chow.

Elizabeth Arbaugh, the zoo’s mammal curator, said Laerka is now just under 50 pounds, and both cubs appear to be similar in size, although Laerka appears to be slightly larger than Astra.

Full-grown polar bears stand 6 to 9 feet tall; weigh 450-1,400 pounds; and live to be 21-24 years old.

While zoo staff opened a secondary room from the maternity den where Suka and Astra spent most of their time so that Astra could begin learning to swim in a shallow kiddie pool and explore a more expansive space with more toys and climbing opportunities, Laerke followed similar steps, moving into a similar space equipped with the same developmental tools.

On April 26, zoo staff monitoring Astra’s development decided to open the door to the polar bears’ habitat in the Arctic Ring of Life, and Arbaugh said Suka and Astra walked right out.

While the pair initially hugged the wall of their habitat and exercised caution, they were both soon exploring and interacting with the outside environment. Suka and Astra are now free to roam between the indoor and outdoor portions of their habitat during zoo hours.

Detroit Zoological Society Chief Life Sciences Officer Scott Carter added that Laerke is also allotted time in the morning before the arrival of guests to explore the outside portion of her habitat.

“They have been exploring the cave. They play and roll in the grass, and they have really been enjoying their time outside,” Arbaugh said. “It’s been wonderful. A lot of people have been able to watch them.”

Staff is not yet sure whether Laerke can be reunited with her mother and sibling. It all depends on the bears and their temperaments, as staff tries to be as hands-off as possible to mirror the conditions of the bears’ wild counterparts.

“It’s always such an exciting time when they get to go outside where guests can see them,” Carter said. “Astra is finding things to pick up and knock over and carry around or stand on.”

The Arctic Ring of Life, which also houses arctic foxes, consists of a tundra and a pack ice portion. While Suka and Astra are being kept on the tundra side, Nuka, the twins’ 16-year-old father, is living on the pack ice side; however, the polar bears can still see and smell each other.

Carter said the plan was always to keep Suka and her cubs separated from Nuka until they are 2 years old, or close to full-grown.

On Feb. 8, 20-year-old female polar bear Anana died from advanced heart disease. She was not killed by Nuka during a breeding attempt, as was originally believed, according to a recent in-depth review conducted by the Detroit Zoological Society and veterinary pathologists at Michigan State University and endorsed by the zoo’s Animal Health External Review Panel, according to the zoo.

Analysis of Anana’s heart tissues revealed she experienced acute heart failure or a fatal arrhythmia before or during breeding attempts. The bite wounds to her head and neck from Nuka aligned with typical polar bear breeding behavior, although his observed behavior of moving her around the habitat after she became unresponsive was possibly due to his confusion by her behavior, according to the zoo.

Due to COVID-19 restrictions, the Frederick and Barbara Erb Polar Passage for underwater viewing is currently closed.

The births are part of the Association of Zoos & Aquariums Polar Bear Species Survival Plan, a cooperative population management and conservation program that helps ensure the sustainability of healthy captive animal populations. There are currently 56 polar bears in 25 AZA-accredited zoos and aquariums, according to the zoo.

The Detroit Zoo is located at 8450 W. 10 Mile Road, west of Woodward Avenue.

For more information, call (248) 541-5717 or visit detroitzoo.org.