Tree mallow
Tree mallow flower

Puffin © Akinori Takahashi




The number of Atlantic puffins on the east coast of Scotland have dramatically increased over the last 40 years, indicating that conditions for puffins are favourable. Yet for one of the largest UK colonies of Atlantic puffin (Fratercula arctica), at Craigleith, an island off the coast of North Berwick, the number of puffins have halved in the last 5 years.

Recent research suggests that this sharp decline in puffin numbers is due to the invasion of this island by tree mallow (Lavatera arborea), a Mediterranean-Atlantic herb that can grow up to 3m tall and form dense stands. Puffins are unable to breed successfully and abandon their burrows in areas where tree mallow has invaded. It is likely that this plant is an introduction to these islands, perhaps having spread from coastal gardens into natural and semi-natural habitat along the east coast of Britain.

There is growing concern among conservationists and local communities alike that the current expansion of tree mallow on several seabird islands may suppress puffins in particular, and will lead to the loss of valuable maritime cliff vegetation, a Biodiversity Action Plan habitat.

A project, funded by the Scottish Executive under the Biodiversity Action Grants scheme, was initiated in July 2005 through which we aim to better understand the expansion of tree mallow on seabird islands, and to develop practical approaches to control the spread of tree mallow and halt the loss of biodiversity caused by tree mallow invasion.


This project is jointly funded by the Natural Environment Research Council and the Scottish Executive. Initial funding was provided by the British Ecological Society.