Regulation of nematode fecundity in the ring-necked pheasant (Phasianus colchicus): not just density dependence

body length body measurements dimension dimensions dynamique des populations ecologia ecologie ecology experimental infection faisan fecundity fertilidad fertilite fertility heterakis gallinarum host parasite relations in vivo experimentation infecciones por nematodos mensuration corporelle nematode infections phasianus colchicus pheasants population dynamics size