Polar bears Luna and Sakari back to sharing habitat ahead of breeding season
It’s the season of love — not just for those celebrating Valentine’s Day, but for the Buffalo Zoo’s polar bears as well.
With polar bear breeding season right around the corner in early spring, Luna and Sakari are back to sharing their exhibit in hopes to promote an environment where the pair can successfully breed.
While Luna and Sakari are quite familiar with one another at this point, getting animals on breeding recommendations comfortable with one another requires the utmost attention and care from our keepers. So what goes into this process?
Introductions between animals on breeding recommendations start off behind the scenes, first with ensuring they’re each comfortable in their spaces and with their keepers. Eventually, the animals will begin a viewing period, oftentimes behind a mesh screen to prevent them from mingling initially. This helps give keepers a better idea of how the pair will interact together and their personalities, taking note of aggressiveness, timidness and everything in between.
All animals are different when it comes to introductions, with larger carnivore animals especially needing extra attention to detail. For example, it’s not uncommon for tigers to swat or vocalize at each other during physical introductions as they set boundaries. Of course, keepers want to avoid these types of incidents if possible, and they’ll use tools like air horns to try and separate animals if they become too aggressive.
In the case of our polar bears getting acquainted, keepers look for behaviors like the male making a “chuffing” noise, which is a common way for the bears to communicate with each other and express they’re friendly. Fortunately, Sakari is an “expert” at it according to our keepers, and it didn’t take long for the pair to get comfortable.
As they begin to share a habitat once again, visitors may start to see some acts of courtship between the bears. Sakari may follow around Luna or they may exhibit some playful behavior, all of which typically precedes breeding. While the two may look like they’re getting a bit rough at times, don’t be alarmed — it’s all common playfulness, but due to their size it can be appear a bit over the top.
Polar bear breeding can be tricky due to a variety of factors. Firstly, they are delayed implanters, meaning the female’s fertilized egg typically won’t be implanted until months after successful breeding. Since polar bears can also have a pseudo or false pregnancy, there is no effective “pregnancy test” for the species, which leads keepers to rely on Luna’s behaviors to get some sort of clue. More likely than not, keepers will be just as in the dark about a polar bear’s potential pregnancy as zoo visitors.
Another tricky part is that polar bears have one, defined breeding season, which means if there is not a successful pregnancy, then our staff as well as Luna and Sakari have to wait until next year to try the process again. This means putting the bears in the best situation to encourage breeding is incredibly important for the conservation of the species.
Other animals, such as big cats, go through monthly estrus cycles, which allows for more breeding opportunities throughout the year.
There were once again no polar bear cubs born in the United States in 2025, and with their vulnerable status in the wild, it’s imperative that we continue to learn as much about these animals as we can. The Buffalo Zoo, as one of just about two dozen zoos in the U.S. with polar bears, is proud to support conservation and research efforts for these incredible animals, and that mission will continue into 2026 and beyond.
Sakari and Luna will likely share their exhibit into the summer, but there’s no concrete timeline for the breeding process. Luna will typically show signs that she’d prefer Sakari to leave her alone at some point, and that leads into her denning season around September.
You can now see Luna and Sakari on exhibit together daily! Be sure to say hello during your next Buffalo Zoo visit.
