I have stalked Sika in the northern highlands for well over 36 years. When I first started in the area of Sutherland there were areas where Sika had not colonised. Slowly but surely over the years this has changed, and now they are common across all the areas north of Inverness, right down through Loch Ness and beyond.
Sika are by there very nature elusive, and in Scotland the FC have tried and tried to eradicate them, without success as far as I can see. Hence them being mostly edgy and older beasts not moving until the light is almost gone. Even in the rut, they rarely let their guard down. Plus they can carry a shot too.
I have seen stags on the open hill, especially when the rut is on, and hinds too. However good cover is nearly always near by. The spread of commercial forestry in the early 1980's and 1990's also helped the spread of the species in my opinion. The thick cover, adjacent to open hill, large fire breaks with some grazing, make it ideal habitat for Sika.
When sika start to move out and colonise new areas, it is nearly always young stags turning up first. They will hybridise with a young Red hind too, if there are not enough Sika hinds in the area. I am also of the opinion that where Sika move in, Roe eventually dwindle in numbers, to the point of vanishing all together. Sika stags can be very aggressive, and it is the only species of deer that I have had charge me when wounded on two occassions, whilst tracking them in commercial forestry with my BMH.
I have also stalked them in the West country for around 6 years on some 750 acres I had through my fathers cousin, now passed on. Here it was not unusual to see groups of 20 to 40 animals, sometimes. However they appeared to me to be much easier to stalk, and far more tolerant of people. Weights were higher, and I well remember taking one stag out of a group of about 12 animals, that took 2 bullets from my 25.06, perfectly placed before it jumped a small fence and died. It took 3 of us to drag it out of the thick cover, one of whom is a member on here. Larder weight, with gralloch, pluck, legs and head off, was 150lbs. The heaviest Sika I have ever shot.
They are a challenge to stalk and kill at times, but the venison is top notch, and my favorite venison.