‘IT’S the world-class wildlife and the Lord of the Rings drama that draws people to the island,” says my Nature Scotland guide Theo as I tear my gaze away from the otter working his way along the shores of Loch na Keal. It’s just long enough to peer down the telescope and enjoy a close-up of a pair of nesting sea eagles. Welcome to Mull, an isle that really comes into its own from autumn into winter.

You won’t find any lazy, hibernating squirrels on Mull – they don’t even have squirrels on Scotland’s fourth-largest island. The wildlife here comes out rather than hides when the leaves start to fall.

Mull has a breathtaking wildscape of flora and fauna that thrives around the only Munro on a true island in Scotland, a sweep of Atlantic coastline and rich patches of ancient forest and moor. My first base could not be better set up for wildlife viewing. I ease off a CalMac ferry at Craignure and see a gannet and a shag before I even check in at the waterfront Isle of Mull Hotel & Spa (www.crerarhotels.com).

The next morning, I scan the coast from my plush Scandi-Scot chic bedroom and spot a large male otter trotting along, delighted with the crab he is treating himself to, on the shoreline in front of me.

The National: An Otter on the coast of MullAn Otter on the coast of Mull

I treat myself, too: to a massage at the slick spa and dinner in the Oran na Mara bistro. I dine on boat-fresh Mull king scallops with chorizo, followed by the local catch of the day. It’s a sublime experience, bubbling in one of their outdoor hot tubs as the birds get active and the sun eases down over the Sound of Mull.

On my second day, I meet Theo at his minibus and he enthuses to our small group about Mull’s wonderful array of wildlife, picking out spots on a giant map. The highlight for many visitors, he says, is its re-introduced population of sea eagles.

“The beauty is they came back here naturally after being introduced from Norway to Rum in 1975,” Theo says. “They decided to fly over the water to Mull and liked it so much they stayed. It feels amazing to have 22 pairs now nesting on Mull.”

It’s easy to see why the sea eagles chose Mull. On Loch na Keal, I watch them and that otter. But that is not all. Mull is a 360-degree wildlife experience. I sweep around and, high in the crags, I find a pair of golden eagles soaring high in the thermals. Theo explains the similarities and the key differences between the two eagle species. I’m stunned to learn golden eagles can dive down at speeds of well over 100mph to whack into their prey with irresistible force.

Reluctantly, we leave the loch after lunch but then the next glen brings mighty stags rutting and hen harriers speeding along too, before we see another otter in the run back up the Sound of Mull to Tobermory.

Tobermory is my second base. And what a base! I’m trying out the RentaHostel scheme from Hostelling Scotland (www.hostellingscotland.org.uk), which means I’ve got the run of Tobermory Youth Hostel for the weekend.

You can only do this in autumn and winter, which is ideal when Mull’s wildlife is at its best. I’m joined by my family, my brother and his kids, plus the Teeces and the Nortons. In all, we have 15 guests spread across eight bedrooms, many of them with views out over Tobermory Bay and the porpoises I often spot there.

The hostel proves the ideal base for Tobermory, with the Mishnish – one of the best pubs in the Scottish isles – a few doors away. There are myriad shops, cafes and restaurants to dip into, including the real Aladdin’s Cave that is Brown’s Ironmongers, which had been taken over by new owners on the day

The National: Taking a close look at the huge array of wildlife on the islandTaking a close look at the huge array of wildlife on the island

I arrived on Mull. You could spend a whole weekend ensconced happily on this waterfront main street.

The hostel kitchen is great for cooking up a local produce storm. We snare fresh mussels from Loch Spelve (£6 for 5kg!), its own smoked fish from Tobermory Fish Company, the famous Isle of Mull Cheddar from the hill just up from the town, and both gin and whisky from Tobermory Distillery. And we enjoy it all with a great view of the water.

The hostel proves an ideal base for an out-of-season walk when the high hills have less appeal. We embark on my favourite Mull short hike, which eases west along the cliffs from the village in search of the whitewashed drama of another Stevenson creation – Tobermory Lighthouse.

The kids are delighted to see a seal and even more so a brace of bobbing porpoises. We find wee crabs in the rockpools on the shore and picnic watching the gannets, shags and gulls.

Reluctantly heading back on CalMac after four days wrapped in the out-of-season charms of Mull, I spy a flock of Canadian Geese swooping in from Greenland. I can see why they make a migratory beeline for Mull. It looks and feels at its best when summer burns out and the fiery reds and deep oranges of autumn take hold and the wildlife really comes out to play.

For more information see www.visitscotland.com and www.wildaboutargyll.com