Using human-imprinted pheasant (Phasianus colchicus) chicks to investigate farmland foraging potential

Abstract

Pheasant chicks, like many other farmland birds, require a large proportion of invertebrates in their diet for successful growth and development during their first few weeks. This study used human-imprinted pheasant chicks as a novel sampling tool to investigate which arable habitats provided the best foraging. Using human-imprinted chicks decreased sampling bias and allowed a biologically relevant method of assessing invertebrate availability within each habitat. Faecal analysis was used to identify which invertebrates were eaten and correction factors established to take into account the differing digestion rates of different fragments. The validity of using commercially farmed chicks for this study was confirmed by the comparison of wild and farmed strain chicks. The value of non-cropped areas, both long-term set-aside and crops planted for game cover, in terms of diet and cover is confirmed. Greater proportions of preferred prey groups were consumed in both types of set-aside than in the commercial crop fields. Interestingly, no difference was found between spring and winter sown cereals and non-cereal crops. The long-term set-aside areas were found to be particularly beneficial to foraging birds as their vegetation structure allowed easy access to potential prey items. As farming has intensified, many farmland birds, which also require invertebrates during their early stages, have declined. If the diet of imprinted pheasant chicks is comparable to those of other farmland birds this method could be used to accurately assess benefits to avian conservation on a wider scale. Human-imprinted grey partridge foraging with pheasant chicks showed similar behaviour and ate similar insects indicating that habitats benefiting one are likely to benefit the other. Faecal samples collected from wild broods of other farmland birds - the skylark, yellow wagtail and lapwing - showed certain similarities in dietary preference implying that careful comparisons may be made.