Zookeeper Andrea Dougall explained that the otters are not prolific breeders—they’re one of a few species that reproduce by “delayed implantation.” Otters mate in spring but don’t give birth until almost a year later. That’s because the fertilized egg hangs out for 10 months in-utero before it implants and grows.
This is the first litter for four-year old mother Ginger. When her pups were born February 15, they weighed a mere 100 grams. Tallullah and Ahanu have spent most of their young lives in seclusion, but were recently debuted to the public.
Though they’re still found across North America, river otters are endangered in some areas. Dougall explains that may be because they need clean, fresh water, and they’re extremely sensitive to pollution.
Video of the newborns should be available soon. But for now, here's a look at some adult otters and their human admirers:
More Oakland Zoo video here.