Unseen guardians of Cape Peron

Drive out to Cape Peron, which projects into the rich waters of Shark Bay, and you may be confused to hear the sound of barking dogs - with no dogs anywhere to be seen.

This is a cunning device to keep pests out of Francois Peron National Park which sits at the end of the cape.

A vermin-proof fence has been built across the narrow neck of land at the base of the peninsula, and where the road passes through is a cattle grid.

"Ah," says Harvey Raven, boss of Monkey Mia Wildsights and my guide on this tour, "but cats and foxes are quite capable of walking across the grid. So what would keep them away?" Dogs?

"Correct," he says, "but you wouldn't really want dogs in the park either. So what could you use to guard the entrance?"

He pauses while I fail to answer.

"The dog's bark, of course."

Any movement near the grid triggers a recording of a barking dog and a high-pitched whine that most animals find unpleasant.

This device, plus a rigorous campaign to remove pests, has made possible the reintroduction of endangered species such as bilbies, woylies, mallee fowl and woma pythons, and has helped the recovery of other populations.

That, in turn, means it's well worthwhile going on a Monkey Mia Wildsights 4WD tour or a Wula Guda Aboriginal Cultural Walk to see the strange and wonderful wildlife found around the shores of Shark Bay.

Aboriginal guide Dean Capewell took us on a walk into the arid hills around the resort and outlined the story of the local Aborigines - including showing us a cave where his greatgrandmother was born - and their culture.

He pointed out the tracks of kangaroos, bilbies and snakes, tracked down tasty goannas and plump bobtail lizards, plucked sweet berries and bush tomatoes off the shrubs, and found water in what seemed dry places.

Capewell is passionate about his self-appointed task of educating visitors on the Aboriginal perspective of Shark Bay and is delighted to see the land of his people recovering from years of abuse.

"The land has been very sick," he says. "But it is now starting to get better and that is good."

Raven, an enthusiast for his adopted home in Shark Bay, takes the 4WD to rarely used bushtracks, lonely sand dunes, deserted beaches and isolated clifftops where outsiders rarely go.

On these quiet tracks you can find thorny devils - nasty looking but perfectly gentle - bobtails, goannas and snakes basking peacefully in the sun. One 2m mulga - or king brown - snake, a species which has the largest output of venom of any snake in Australia, was so big it startled even him.

From clifftops like the impressive Eagle Bluff you can see kestrels soaring overhead and sharks, rays, turtles, dugongs and big fish swimming in the waters below.

The most remarkable of the beaches is Shell Beach which is made up of millions of tiny white shells piled 10m deep and 120km long, compressed over the centuries into solid blocks of shell.

In the past this used to be cut with chainsaws and used for buildings - including Raven's home in the town of Denham and the nearby Old Pearler Restaurant.

"I've done a lot of research and I'm absolutely convinced that there's nowhere like this place in the world. There's no other beach like this and there's nowhere that has the animal life that we see every day. It's very, very special."