how did the oak get to sweden?
Hoarding
During the autumn, the jay hoards thousands of acorns to use as winter food. They are dug down in the ground and relocated months later with impressive precision.
Hide and forget
Despite its memory, the jay forgets some of its hidden treasures. With time the forgotten acorns germinate and new oaks grow up. If you find a single oak plant in the middle of a pine or spruce forest, you know who planted it!
The spread of the oak
It's difficult for the oak to spread, since the acorn fall directly to the ground next to the mother plant. But a jay can carry acorns for miles, in order to hide them.
Now, how did the oak get to Sweden?
Shortly after the Ice Age, the oak quickly spread northward from Skåne in the south up to the middle part of Sweden. It is a 500-kilometre distance and it took around 2,000 years, an average of 250 meters per year. But not without the jay's help!
