BBC Northern Ireland rural affairs correspondent
They arrive in Northern Ireland exhausted and hungry after their 800 mile flight from Iceland.
The older birds lead the skeins of whooper swans in for their final approach towards Lough Erne and the nearby grassy fields which farmers have prepared for the flocks.
More than 2,500 of these distinctive swans winter at sites around Northern Ireland which are internationally important.
Swans are wary of humans and Martin Cassidy could not get closer
Farmers in Fermanagh's environmentally sensitive area are being encouraged to manage their land for the benefit of the 1,000 whoopers which arrive each year in the lakeland county.
The lush green grass in fields running down to the lough is appetising for the hungry swans, but having spent all summer in the wilds of Iceland, they are difficult to approach.
Ryegrass grown for cattle and sheep is very much to their liking, and importantly, the farm animals are removed early to allow a dense sward to build up for the swans to feed on over the chilly winter months.
Swan farming has now become a reality.
In areas which the birds frequent, farmers can opt to take part in a special European-funded swan project.
As well as undertaking to get their animals off the fields in early autumn, landowners also agree not to use slurry or pesticides during the winter months.
The swan project, which aims to provide the swans with clean wintering sites, is proving popular with Fermanagh farmers who can earn up to £45 per acre for eligible fields.
Swans are well known in these parts for their healthy appetite for grass, and the conservation scheme now provides compensation for the extra beaks to feed.
Local people reckon a couple of swans can graze as much as a sheep.
"They need green grass like we have here, and they like water where they can roost at night," explains countryside management adviser Patrick McGurn.
"Of course, they can't take off in small fields so you need big open fields, and we encourage farmers not to put fences up as that is going to limit swans."
Whoopers are wary of humans, and their long grazing necks are raised bolt upright when the birds are disturbed.
Having to take off to avoid intruders means using large amounts of energy. The last thing these swans want is visitors.
The whoopers are late this autumn, delaying their annual migration to take advantage of the unusually mild weather.
Race against time
For the cygnets hatched in Iceland, every extra day counts.
They face a race against time to be strong enough to escape the Arctic winter and make the first of up to 20 visits south to Fermanagh.
With winter closing in, hundreds of swans are now on their way. But that sea crossing is gruelling, particularly in bad weather.
Flight speed is also influenced by the amount of fat carried by the birds.
Mature birds in peak condition can reach speeds of up to 55 miles per hour, while weaker birds may put down in the sea to rest.
But the flocks are now on the move and in the next few days, people in Fermanagh will be watching the winter skyline and listening as the whoopers trumpet their arrival for another winter by Lough Erne.