Puffins living on Craigleith in Scotland are under threat from an alien plant spreading across the island.
The number of birds living there has dropped from 40,000 to 2,000 over the last five years.
The Mediterranean plant, which is called tree mallow, is clogging up the ground where the black and white birds like to burrow and make their nests.
Tree mallow used to die off every year because of frost, but recent mild winters means it's now out of control.
Scientists at the Centre for Ecology & Hydrology in Banchory think that if they can work out how to stop tree mallow spreading they can save the birds famous for their little orange legs.