The effects of releasing hand-reared birds on the British pheasant population.

Abstract

Pheasants Phasianus colchicus were probably introduced to Britain by the Normans in the 11th century. They are now the most common gamebird in the lowlands and the major quarry species, extensively hunted for sport.
Britain contains a sizeable resident breeding population of the pheasant but the popular method of hunting requires high densities of birds if it is to be profitable. British pheasant shooting operates by a line of beaters driving birds from an area of woodland or other suitable cover to encourage them to fly over a line of standing sportsmen armed with shotguns.

To create high enough densities to enable this style of shooting many estates rear chicks in large enclosures using methods similar to modern poultry production. The young birds are then placed in large open-topped pens in areas of woodland during the summer and allowed to disperse into the wild. The Game Conservancy has organised a scheme, The National Game Census, to monitor the numbers of birds released and shot on around 600 estates each year since 1951. Taking the scheme as a whole, over this period the numbers shot have risen from an average of 60 to 120 per km². The numbers reared have also increased from 50 to 180 birds per km² (Hill & Robertson 1988a).

Hand-reared birds are known to demonstrate lower rates of survival and breeding success than their wild counterparts. Increases in pheasant density that result from large scale rearing may increase parasite loads and density dependent rates of predation for both the wild and reared portions of the population. The percentage of the population shot each year also rises and this may lead to overshooting of the wild population. Lastly, the increase reliance on hand-reared birds to provide sport can lead to declines in the management of habitats and control of predators for the benefit of the wild population.

This paper aims to describe the changes in British pheasant populations over the last 26 years and discuss the impact of large-scale hand-rearing on the wild stock.