The Ecology and Management of Hand-reared and Wild Pheasants (Phasianus colchicus) in Ireland.
The Cormnon or Ring-Necked Pheasant Phasianus colchicus is the most prominent gamebird over much of temperate Europe and North America. Introduced into Ireland fron Britain in 1589 (O'Rourke 1970) this species can now be found in each of the thirty-two counties (Sharrock 1976).
The natural range of this species extends from the Caucasus, along the Black Sea and East across Asia to Korea, Manchuria, China, Formosa and Japan (Delacour 1977). This natural range has been extended due to introductions by man. Long (1981) records introductions into almost fifty countries and the pheasant can now be said to be naturalised throughout most of Europe and North America.
The pheasant is the major quarry species in Ireland and this has led sportsmen to rear and release large numbers of young birds in an attempt to increase subsequent shooting bags and the size of the breeding population. Although numerous studies record the percentages of hand-reared pheasants shot per season (Buss 1946, Ginn 1947, Kozlik 1948, MacNamara & Kozicky 1949, Harper et al. 1951, Dorr 1952, Low 1954, Allen 1956, Anderson 1964, Bray 1967a, Gill 1976, 1977) there are relatively few studies giving details of the timing or causes of losses (Burger 1964, Hessler et al. 1970, Jarvis & Engbring 1976). Furthermore it is only recently that the behaviour of hand-reared pheasants has been compared with that of wild bred stock but there are no detailed comparisons of their ecology. The only information available on the success of release by Irish sportsmen arises fron a small government survey (Forestry and Wildlife Service 1979) and virtually nothing is known about the activities of hunters in this country. A better understanding of the success of pheasant release and the ability of hand-reared to supplement wild stocks will benefit the management of game stocks and have implications for the conservation of endangered species, such as the Cheer pheasant, Where similar techniques are being used to reintroduce locally extinct populations (Mirza 1979, Severinghaus et al. 1979).
Increasing agricultural intensification over recent years has caused concern regarding the status of many bird species (Murton & Westwood 1974, Fuller 1982). However, as the pheasant is one of the few species whose conservation can be of financial benefit to landowners its management can be an important factor in the maintenance of diversity in agricultural systems, most notably through the planting, management and retention of woodland (Shoard 1980, Cobharn Resource Consultants 1983). This is particularly true in Britain although not so important in Ireland where the absence of payment for shooting rights gives no financial incentive to the landowner. The more efficient management of natural pheasant populations should benefit both the sportsman and the wildlife found on agricultural land.
The aims of the study were therefore:
- To survey the range and efficiency of pheasant management currently in use in Ireland.
- To examine the dynamics of a pheasant release managed on the lines typical of an Irish shoot.
- To compare the ecology of wild and hand-reared pheasants.
- To assess the contribution of hand-reared birds to the population breeding in the wild.
- To relate the findings of these investigations to possible improvements in the management of the pheasant in Ireland.
One chapter is devoted to each of these topics and the results are discussed separately with a summary and general discussion in Chapter 5. Parts of this thesis have been published elsewhere (Robertson 1985a 1985b, Robertson & Hill 1986, Hill & Robertson 1986) but are included in full in the text while other works not directly relevant to the central topics are presented as appendices (Robertson et al. 1985, Robertson & Whelan in prep.). For clarity, those pheasants hatched and raised by a naturally breeding hen are referred to as ''wild'' while those hatched and raised through the actions of man are termed ''hand-reared'' or 'released' throughout the text.