The study is partly funded by the Defence Estates, which will improve the understanding of the sika population?s behaviour, movements at various stages in the year and its impact on the environment.

Sharply rising sika numbers have created concern among local conservation groups, particularly about the impact on other species? habitats, which in the Poole Basin include reed beds, saltmarsh, bogs, heath and ancient woodland.

Sika are regular visitors to the MOD ranges at Lulworth on the coast, so the study is concentrating on this region.

Rosie Rowe from Defence Estates told Shooting Times magazine: ?At Lulworth, the MOD is the custodian of some incredibly rare species and habitats. I?m delighted that the collars are finally in place to give us a much-improved understanding of the sika deer?s effect on other species. I ask Dorset?s deerstalkers to be vigilant and not to cull tagged or collared sika deer.?

Over the past two years, a team of deer catchers and conservation volunteers have captured and collared suitable deer. Once in the net, animals selected for their age and health were tagged, collared and released.

Saturday, February 21st, saw the final five stags kitted-out as part of the research initiative.

The study zone includes the Armoured Fighting Vehicle School, which despite being used for tank live-firing since 1916 is designated an SSSI by Natural England.

The ranges are home to many rare species, including the woodlark and nightjar, but they also provide excellent habitat for sika, with plenty of food and cover, and minimal human disturbance compared with surrounding estates, despite the live-firing on the ranges.

The MOD has managed the deer in the area for 25 years.

Dr Anita Diaz, the project leader at Bournemouth University, said: ?The GPS collars provide an excellent opportunity to study the ecology of both stags and hinds, and will significantly advance what we already know about how this introduced species uses habitats in Purbeck.?