Effects of Spring Feeding on Body Condition of Captive-Reared Ring-Necked Pheasants in Great Britain

Abstract

In Great Britain, the captive rearing and release of ring-necked pheasants (Phasianus colchicus) during summer to supplement wild stocks for shooting is widespread, but breeding success of surviving females the following spring is poor. We hypothesized that reduced body condition as caused by low availability of natural food during spring and cessation of supplemental feeding in late winter may affect subsequent breeding success. On an estate in southern England, we provided wheat grain on 3 l-km 2 plots from March to June, while pheasants on 3 other l-km 2 plots foraged solely on natural foods. We switched treatments during the second year. We collected hen pheasants from each plot during February and April. Fat reserves of hen pheasants collected in April from food-supplemented plots were maintained at their February levels (76.9 ± 8.0 g; x ± SE), but fat reserves of birds collected from unsupplemented plots were reduced by >50% of their Febmary levels (34.7 ± 6.9 g; P = 0.01). Body mass, muscle sizes, ceca, and small intestine length were more affected by date than supplemental feeding. We suggest that low food availability and poor spring diet as a result of modern agriculture may affect hen body condition and productivity of pheasants in Great Britain.