Dispersal Behaviour and Movement Patterns of Pheasants from Woodland Release Pens.
The large-scale release of ring-necked pheasants, Phasianus colchicus, for recreational shooting in the UK raises concerns about ecological impacts, particularly on sensitive ecological sites. Current assumptions suggest dispersal is typically <500m from release pens, yet empirical evidence is limited. This study tracked 110 GPS-tagged pheasants from 11 woodland release pens across nine shooting estates, monitoring movements through pre-shooting, shooting and post-shooting phases. Most birds (73%) travelled a maximum distance beyond 500m during at least one of the three phases, with mean maximum distances of 863m, 1,493m and 1,307m per phase. During at least one phase, 26% of the 110 tagged birds spent most of their time (>50%) beyond 500m and 16% beyond 1,000m from their release pens. Early post-release movements were concentrated near pens, but ranging behaviour expanded during subsequent phases, with the percentages of birds spending >50% of their time beyond 500m and 1,000m, respectively: pre-shooting 6%, 2%; shooting 24%, 16%; post-shooting 13%, 9%. Accounting for mortality, the percentages of surviving birds spending >50% of their time beyond 500m and 1,000m increased: pre-shooting (n=110) 6%, 2%; shooting (n=71) 37%, 25%; post-shooting (n=27) 52%, 37%. Dispersal was greater with earlier release dates, higher pen and estate stocking densities and lower vegetative habitat quality in pens. Movements were directional rather than uniform, with most cohorts concentrating activity within a limited directional arc specific to the release site. Conservation site incursions occurred in 28 (25%) tagged birds, particularly where pens were closest to site boundaries; although 10 (36%) tagged birds encroached on conservation sites 872-2,319m from their release pen. These findings show that dispersal of released pheasants is further, more directed, and persistent than currently assumed.