Releasing hand-reared pheasants and red-legged partridges is a common management practice employed wherever the demand for shooting exceeds the levels sustainable by wholly wild populations. In the UK, releasing underpins most shooting activity, primarily because of long-term declines in wild game associated with agricultural practices (Tapper 1999). Populations of wild gamebirds, at levels that can sustain shooting exist only in the drier arable areas of the UK, such as East Anglia, parts of central southern England, North East England and the Scottish Lowlands (Tapper 1999). These regions are still dependent on releasing to some extent while other areas are wholly dependent on releasing.
According to the GWCT’s National Gamebag Census, around three quarters of birds released for shooting are pheasants while the remainder is mostly red-legged partridges. The NGC records information provided by around 600 participating estates throughout Britain on shooting bags (Aebischer 2003). There is no actual quantification of releasing as the NGC is a fraction of the actual shooting estates. However, through extrapolation we estimate that about 25 million pheasants (Sage et al., 2005) and over 6 million red-legged partridges are released onto perhaps 3 million hectares of land. The number of released pheasants and partridges can exceed 20 birds per hectare of estate.
The red-legged partridge shooting season starts on 1 September and the pheasant season on 1 October, with the season finishing on 1 February for both species. In practise, shooting is delayed for around a month and takes one of two formats: ‘rough’ (also known as walked-up) shooting or, more commonly, ‘driven’ shooting. The former involves individuals walking up and flushing their intended quarry whilst the latter consists of a group of ‘guns’ being strategically positioned whilst gamekeepers or a line of ‘beaters’ actively flush birds over the stationary guns.
The majority of released pheasants and partridges are hatched from eggs carried in mechanical incubators and are reared in closed pens (i.e. with roof), often on grass and with night huts, without the presence of adult birds. This is undertaken on game farms, here or on the continent, or on the shoot itself. After 6-8 weeks, the poults are transferred from the rearing pens to release pens. This usually occurs some time in July but also in late June or early August.
Pheasant poults are transferred from the rearing pens to large open-topped release pens, usually situated in woodland, sometimes on the woodland edge. Release pens range from as little as 0.1 hectares to several or even 10 hectares in size. They afford a secure environment within which the young birds can acclimatise to their new habitat. In particular, they give the birds the opportunity to adapt to roosting in the lower branches of trees, thus avoiding the attention of ground predators, especially foxes. The timing of the release is aimed at ensuring that birds are mature and fully adapted to their environment by the time shooting commences in late October or early November.
Sage et al. (2005) estimate there is around 9,000ha of release pen (1% of the total woodland area) in England. The GWCT suggest that around 700 birds per hectare of release pen is an appropriate stocking level (Sage & Swan, 2003) but releases in the order of 8,000 birds per hectare of release pen, have been documented. The mean stocking density reported in Sage et al. (2005) is currently 1,800 birds per hectare of pen.
Following release, a gamekeeper typically supplies food, water, and a level of predator control. Habitat management, such as the planting of cover crops may also take place. Wing clipping at the time of release can help ensure that poults remain within the relative security of the release pen for several weeks before dispersing out into areas that will ultimately be ‘driven’ on shoot days. This method of releasing pheasants into large open-topped pens from which ground predators have been excluded was developed in Britain by the GWCT and others and is used almost universally in the UK.
Releasing red-legged partridges
There are a variety of techniques involved in the release and management of red-legged partidges for shooting, and the fine detail of release method varies between shoots. However in general red-legged partridges are usually released into much smaller discrete units compared to pheasants. A medium to large shoot may use 20 or more closed-top release pens containing 50 to 300+ birds per pen. On larger shoots, typically 250 birds will go into a pen of about 10x10 metres, giving a much higher stocking density than for pheasants. As with pheasants, the timing of the release is aimed at ensuring that birds are mature and fully adapted to their environment by the time shooting commences in late September or early October.
Each pen is usually associated with a specific block of dedicated game cover in otherwise open country, usually arable farmland but also grassland. On larger partridge shoots there may be several pens each containing several hundred birds feeding into one large block of cover.
Typically, birds are placed in pens at around eight weeks of age where they are held for two to four weeks before release. Birds are then ‘trickle’ released whereby a small quantity of birds are released at a time while retaining a successively smaller number of birds in the pen. The birds remaining in the pen call to the released birds which helps prevent the released birds wandering off. Food is provided close to the pen to hold released birds in the vicinity. The alternative approach is to release all the birds from a pen at the same time.
The objective of releasing is to ensure that proposed drives for shooting will contain sufficient birds for the guns. Release areas must therefore be attractive to the released birds and be able to ‘hold’ them. Game cover-crops and other fed areas are frequently used to draw released birds away from a release point so that when flushed for driven shooting there is a tendency for the birds to fly back to the release point.
Based on the NGC, the proportion of released pheasants that are actually shot is, on average, about 40% of the release (Aebischer, 2003). This estimate includes wild birds and birds released on other shoots and may be an overestimate. For a shooting estate, this return rate is of great importance. It will vary enormously from one site to another (Robertson et al., 1993). This average figure in Britain, however, compares favourably with return rates using other release methods elsewhere in the world. In the USA where birds are often released straight from cages into the wild in the days immediately prior to shooting, with no attention to feeding or predator management, returns indicate poor survival in the range 2% - 30% (e.g. Haensly et al., 1985). In France, Mayot (2003) found that large ‘English’ pens, produced a return of shot birds 35 % higher than the equivalent French method (small closed top pens stocked nearer the shoot date).