The first sheep census was carried out in 2005 but information relating to mountain sheep has only been collected since the 2014 census.
Data obtained from the Department of Agriculture, Food and the Marine show total mountain sheep figures, including cross breeds, of 1.62 million in 2014.
That number increased by over 5.6pc to 1.71 million in 2015. A smaller annual increase of 1.5pc was recorded for 2016, where total figures rose to 1.74 million.
Teagasc enterprise leader for sheep, Michael Diskin, says that if there weren't sheep in the hill areas, they would grow wild with major implications for the environment and tourism. He insists that there simply has to be a future in hill farming.
"If we allow the people who are farming the hills now to disappear, the consequences of that from an environmental, tourism and sociological point of view would be disastrous," he says.
"I think it is incumbent on Government to have policy in place to maintain those vulnerable and important parts of Ireland, and hill sheep is very much central to that."
Under-grazing now is a bigger problem in hill areas than over-grazing, which became an issue in the early 1990s as a consequence of increased stocking rates, following the introduction of headage payments.
Attention has been focused on this issue since gorse fires blazed earlier this year across Sligo, Galway, Mayo and Donegal.
Commonage Framework Plans were introduced in the late 1990s to address this, which resulted in compulsory destocking on all commonages.
The introduction of decoupled payments under the Single Payment Scheme in 2005 further reduced the incentive to put sheep on to commonage land.
Land designations have also placed major restrictions on farming activity, with 39 actions requiring consent.
Brendan Joyce is a sheep farmer in Connemara, and vice president of the Irish Natura and Hill Farmers' Association (INHFA), which represents 5,000 farmers on marginalised, hill and designated land.
He says while the age-profile in all sectors is rising, the difficulty with hill farming in particular is that it doesn't attract new entrants.
"With hill farming you have to be born and reared into it, so it's very important that those who are there, particularly young farmers, are encouraged to stay active," he says.
"The market place doesn't always reward us for the effort that goes into hill farming.
"There's still a critical mass there of people who can survive on it but it's about encouraging people to continue at it and take it up - that is where the difficulty really lies."
The INHFA is looking for the impact of designation to be re-examined.
Other organisations, including the IFA, have made submissions to allow burning dates to be extended.
Seán Malone has farmed through all these changes near Roundwood, Co Wicklow, where he keeps 500 ewes on privately owned and rented land.
The hill land he grazes his sheep on has been designated a Special Area of Conservation (SAC), controlled by the National Parks and Wildlife Service.
Seán is a member of the Wicklow Uplands Council, which works closely with the NPWS to maintain the hills.
Unlike a lot of his neighbours, his son will take over the farm.
"A lot of the younger generation don't want to go to the hills," he says. "At the moment there isn't a living to be made and that's why new schemes are needed to encourage sheep back on the hills and young people to follow them.
"Unless there's enough encouragement to go back, it will be hard to get young people to do it.
"But if young people and sheep leave the hills, it's hard to bring them back to it - the sheep won't settle there unless they're brought back every year, and young people aren't going to give up good jobs to walk the hills," he added.
Sheep Farmer of the Year Joe Scahill farms 400 acres, including 100ac of leased land, 250ac of hill and 50ac of "rougher" grazing land at the foot of Croagh Patrick near Westport.
"We run about 600 Scottish blackface ewes and 25 dry cattle but the land type really is only suited to sheep so you're confined," he says.
His vision for farming is for reduced reliance on direct payments combined with a fairer price for his produce - and he would like to see the money saved going into a pension fund to encourage farmers to retire earlier. He says this would free up land, allowing new entrants to get involved.
"At the moment there is the Young Farmers' Scheme, where a young person gets their Green Cert, and if they can access land they apply to the National Reserve to be given entitlements but all that has done is distort the price of rented land," he argues.
"I'm 47 now and one of my sons is 14 and ideally I should be handing over to him when he's 24. If I wait till pension age, he'll be 34.
"At that stage you'd expect someone to be making their own way and it would be very hard to give up a career to come back to farming then."
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