THE northernmost island in the Orkney archipelago may stretch barely three miles long, but it packs in a lot, be it the towering lighthouse, famed seaweed-eating sheep or the myriad, transient visitors that come from the air.

North Ronaldsay has its own bird observatory and September is a busy time for migrant species passing through. In normal years – when we aren't in the middle of a pandemic – its reputation for rare birds sees twitchers travel from across the globe in the hope of catching a glimpse.

Indeed, September is considered the most exciting month when, at the peak of the autumn migration, almost anything can turn up.

An impressive 341 species have been recorded here since the mid-1980s: a list that includes rarities such as the Siberian blue robin, rufous-tailed robin, yellow-browed bunting and Cretzschmar's bunting.

READ MORE: How the loneliest tree in Scotland became a beloved landmark

Orkney is a regular stop-off for Arctic terns – known as the Pickieterno in these parts, as opposed to Tirrick in Shetland – typically arriving around May and departing by August.

These remarkable birds make a return trip of around 44,000 miles from pole to pole each year, flying between Greenland in the north and the Weddell Sea on the shores of Antarctica in the south – their entire existence spent in perpetual summer.

HeraldScotland:

North Ronaldsay has inhabitants of the four-legged variety too, sheep that can be seen nimbly foraging among the rocks along its shoreline. A first glance they look more like goats with thick fleeces in various hues of grey, brown and red.

Hemmed in by a stone dyke that encircles the island and keeps them off arable land, the sheep dine on seaweed. This gives their meat a distinct flavour – described as "intense" and "gamey" – which is much in demand with top chefs.

READ MORE: A magical Scottish bridge reached through a fairy trail

North Ronaldsay is home to the highest land-based lighthouse in the British Isles, built in 1854 and standing 139ft (42m) tall. Other gems include the Broch of Burrian where Iron Age and Pictish artefacts have been discovered.

What to read: If you can track down a copy, Island Saga: The Story of North Ronaldsay by Mary A Scott (Alex. P. Reid and Son, 1965), is a must as is The Foraging Strategy of the Seaweed-Eating Sheep of North Ronaldsay, Orkney, by I W Paterson (University of Cambridge, 1984). 

Follow the North Ronaldsay Bird Observatory on Twitter @NRonBirdObs or visit nrbo.org.uk. For more information, visit orkney.com