I cycle past him every day and i believe he belongs to someone in the traveller 'village' just south along glengall rd from his field - quite possibly the very friendly irish guy seen walking his staffie every morning through the park. The horse, i think, is looked after reasonably well (ie. fed, watered, blanketed in winter etc), is thankfully not hobbled and indeed occassionally enjoys tearing around his field bucking and rearing! It does seem bit sad that he is all alone apart from bits of detritus that end up in his field and a rather lovely fox that often hangs around his feet at sundown.