The efficacy of a technique to control parasitic worm burden in pheasants (Phasianus colchicus) in the wild

The lower productivity of reared pheasants (Phasianus colchicus) compared to their wild counterparts is well documented. Providing supplementary food for pheasants throughout the spring has been shown to increase their breeding success, primarily through improving hen body condition. In a separate study, individually dosing hens with an anthelminthic in spring to reduce their parasitic worm burden has also been shown to increase their productivity in the wild. In a small-scale pilot study these two techniques were combined to test their efficacy as a means of treating free-living pheasants in spring without the need to catch individuals. The parasitic worms recorded were Heterakis gallinarum and Capillaria spp., both of which are found in the caecae. The results indicated that, in the absence of anthelminthic treatment, worm burden in pheasants increased rapidly between March and April, but in contrast, birds given anthelminthic treated grain had significantly lower worm burden during the same period. Therefore we suggest that this is an effective management technique for treating free-living pheasants in spring. Subsequently, an experiment was carried out to try to assess the best time to allow pheasants access to 'treated' grain in the wild in order to maximise its benefits. Hen pheasants in pens were exposed to infection from the soil. Specific groups of hens were 'dosed' at three weekly intervals with anthelminthic treated food and their worm burdens recorded when they were killed at various times thereafter. The results were not clear cut, but suggested that dosing as late as possible prior to nesting would be most beneficial to the hens.