0:00:02 > 0:00:06Off the rugged coast of Wales lies a special wild sanctuary.
0:00:08 > 0:00:12An island known for thousands of years as a place of pilgrimage.
0:00:16 > 0:00:19Once a home to monks, Celts and Christians
0:00:19 > 0:00:24but always a sanctuary for a special wild visitor...
0:00:30 > 0:00:33Secret pilgrims who arrive on the summer winds
0:00:33 > 0:00:35from distant southern seas.
0:00:37 > 0:00:39BIRDS CACKLE
0:00:40 > 0:00:43CACKLING INCREASES
0:00:43 > 0:00:45Although they come here in their thousands,
0:00:45 > 0:00:49they are rarely ever seen.
0:01:02 > 0:01:06Though Bardsey Island lies a few miles off the northwest coast of Wales,
0:01:06 > 0:01:11it is a strangely isolated place.
0:01:11 > 0:01:14SEABIRDS CALL
0:01:18 > 0:01:22The seas here can be so treacherous that the Welsh call it Ynys Enlli.
0:01:22 > 0:01:26The Island in the Tides.
0:01:29 > 0:01:33Its human pilgrim story started over 1,500 years ago
0:01:33 > 0:01:38when Christian monks came here in search of solitude.
0:01:42 > 0:01:46Its isolation has always made Bardsey a sanctuary for wildlife too.
0:01:50 > 0:01:53The island's clan of grey seals
0:01:53 > 0:01:56take advantage of the summer days to fatten up
0:01:56 > 0:02:00for the autumn breeding season and the winter that follows.
0:02:00 > 0:02:02SEAL HONKS
0:02:04 > 0:02:07Low tide is time to haul out
0:02:07 > 0:02:09and to relax.
0:02:20 > 0:02:25It's a welcome break from the fish-rich but cold Irish Sea.
0:02:32 > 0:02:36As night settles on the island,
0:02:36 > 0:02:39surprising summer visitors gather offshore.
0:02:39 > 0:02:42They have journeyed from the coast of South America,
0:02:42 > 0:02:45lured by the island as a safe place to breed.
0:02:47 > 0:02:51Manx Shearwaters. Though they come here in their thousands,
0:02:51 > 0:02:55they can only be glimpsed in the last light of day.
0:02:55 > 0:03:00After fishing far out at sea, they only dare return to the island
0:03:00 > 0:03:02under the cover of darkness,
0:03:02 > 0:03:05safe from predatory gulls and peregrine falcons.
0:03:10 > 0:03:12BIRDS CACKLE
0:03:13 > 0:03:16In the dead of night, they descend on the island.
0:03:16 > 0:03:18Their mating calls fill the air.
0:03:18 > 0:03:21SCREECHING AND CAWING
0:03:29 > 0:03:33But by dawn, the phantoms appear to have vanished.
0:03:33 > 0:03:38The Shearwaters aren't the only pilgrims to have flocked to Bardsey.
0:03:39 > 0:03:44In the depths of the Dark Ages, the abbey here was revered
0:03:44 > 0:03:49throughout Britain as a sacred place of pilgrimage.
0:03:49 > 0:03:53The ruins of the stone walls the monks first laid,
0:03:53 > 0:03:56can still be seen today.
0:03:56 > 0:04:00So many pilgrims came, never to leave, that legend has it
0:04:00 > 0:04:0220,000 saints are buried here.
0:04:05 > 0:04:10The land is still worked by the handful of year-round residents
0:04:10 > 0:04:13who make the most of the fair summer weather.
0:04:18 > 0:04:20In the patchwork of fields,
0:04:20 > 0:04:22thistles attract Painted Ladies,
0:04:22 > 0:04:25Peacock butterflies, bees
0:04:25 > 0:04:28and migrant Hummingbird Hawk-moths,
0:04:28 > 0:04:32who only appear at the height of summer.
0:04:34 > 0:04:36Bardsey's hardy sheep though,
0:04:36 > 0:04:39stay all year round, keeping the pastures well trimmed,
0:04:39 > 0:04:42attracting the island's latest brood of choughs.
0:04:51 > 0:04:54While the soil provides the choughs with a hearty meal of grubs,
0:04:54 > 0:04:56deeper underground
0:04:56 > 0:04:58the earth hides a special Shearwater secret.
0:05:02 > 0:05:04Although the adults appear to have gone
0:05:04 > 0:05:08their chicks are here, hundreds of them.
0:05:08 > 0:05:11They're just hidden, out of sight.
0:05:11 > 0:05:15And almost out of reach from the wardens of the Bardsey Bird Observatory.
0:05:15 > 0:05:18who carefully monitor the population.
0:05:18 > 0:05:20CHICK SQUEALS
0:05:20 > 0:05:23With their young safe in burrows away from the hungry gulls,
0:05:23 > 0:05:26parents can spend all day fishing
0:05:26 > 0:05:29to keep their fast-growing fluff ball well-fed.
0:05:31 > 0:05:34When the chick is ready to leave the safety of its burrow,
0:05:34 > 0:05:38it may not touch land again for over two years
0:05:38 > 0:05:41when it too returns to Bardsey to breed.
0:05:51 > 0:05:57The Shearwater parents delay their return until the darkest hours
0:05:57 > 0:05:59when the night is black.
0:06:01 > 0:06:06The island's lighthouse, the only light for miles around,
0:06:06 > 0:06:09has for centuries been a beacon of safety for seafarers.
0:06:09 > 0:06:14But on a moonless, misty night, for returning Shearwaters,
0:06:14 > 0:06:17the lights can be deadly.
0:06:19 > 0:06:24The birds are attracted to the beams like moths to a flame.
0:06:27 > 0:06:31Most struggle through, for they must land safely.
0:06:37 > 0:06:41On these dark nights, the wardens keep a watchful eye
0:06:41 > 0:06:45and are rewarded with an intimate view of these unusual birds.
0:06:49 > 0:06:53Safe on the ground, the Shearwaters must now find their hungry chicks
0:06:53 > 0:06:55in the dark.
0:07:07 > 0:07:10For a bird adapted to spend most of its life at sea,
0:07:10 > 0:07:13walking on land is tricky.
0:07:22 > 0:07:26No-one really knows how they find their own burrows in the darkness...
0:07:27 > 0:07:29..but they do.
0:07:41 > 0:07:46In its lifetime, a Manx Shearwater may travel nearly 5 million miles
0:07:46 > 0:07:50returning to the same burrow, year upon year to breed.
0:07:58 > 0:08:03Always in the dark, on its secret pilgrimage to this ancient island.
0:08:17 > 0:08:22As the summer draws to a close, the adults will fly south.
0:08:24 > 0:08:27After months of careful nurturing, they abandon their chicks
0:08:27 > 0:08:32to find their own way to the distant coast of South America.
0:08:33 > 0:08:38The island falls silent, until the next year
0:08:38 > 0:08:41when these wild pilgrims return.
0:08:46 > 0:08:49Subtitles by Maria Frate Red Bee Media Ltd
0:08:49 > 0:08:52E-mail subtitling@bbc.co.uk