Hares that were electronically tagged as part of a university study have revealed the growing threat to their declining numbers.
The movements of two dozen hares in south Armagh were monitored by radio transmitters day and night for a year as researchers examined their eating, sleeping and hiding habits.
Seven died, some killed by foxes, but farm machinery was shown to cause a far greater death toll, especially at the height of the breeding season when silage cutters mow down the long grass where leverets (baby hare) are born.
Experts said that unless more is done to protect their natural habitat, the Irish hare population is in danger of going the same way as the corncrake.
Hundreds of thousands of hares could be found across the countryside at the turn of the 20th century, but following changes in farming practices, the numbers last year were estimated at 27,400.
A Queen's University research team, led by Dr Neil Reid, Quercus Centre Manager at the School of Biological Sciences, found that hares required a patchwork of good-quality grassland for feeding as well as tall vegetation, such as rushes, for hiding and sleeping.
Dr Reid said: “Hares may mistake the tall grass of silage fields as a good spot for lying-up and giving birth. Silage is harvested during the peak period when leverets are born in late spring and early summer and the machinery used may trap and kill young hares, driving down the local population year after year.”
A new Northern Ireland Countryside Management Scheme, implemented by the Department of Agriculture and Rural Development, includes measures to target hare conservation.
It is a ‘delayed cutting and grazing’ option and farmers who sign up receive hectarage payments for postponing the cutting of silage until after July 1.
But there is now a clear need for a change in mowing strategy, according to Dr Reid. He said: “We may have 40 shades of green but we have created a desert of grass. Variety is the spice of life. Wildlife can't survive in a pristinely manicured landscape of one habitat.”