The cliffs to the west and north of Canna; and south of Sanday hold around 15,000 seabirds of 14 different species.

In European terms, the shag colony is probably the most important, formerly representing 2% of the European population, and currently the second largest in Scotland.

The main nest site is in the boulder fields at the western end of Canna (Garisdale), stretching round to the South (The Nunnery) with further sites to the north (Geugasgor).

There are large colonies of Common Guillemots and Razorbills at Geugasgor and the south-west of Canna, while Puffins are mainly confined to some stacs off Sanday.

The figures in the table represent the total breeding birds for each species.

Manx Shearwaters used to nest along the slopes in the centre of the island but are now confined to some inaccessible gullies to the south-west.

Numbers have been monitored for over 30 years by the Highland Ringing Group which tells us of the health of the colony.