Seasonal Cycle of Reproductive Physiology in the Black-Billed Magpie

摘要: The Black-billed Magpie (Pica pica) is a prominent species in many parts of western North America. However, with the exception report by Davis (1955) which determinate laying pattern was noted, information on reproductive physiology magpies not available. Recent studies behavioral and ecologic factors influencing reproduction birds (see reviews Lehrman 1961; Marshall van Tienhoven Farner Follett 1966) have shown value field investigations studying processes suggested need for further work correlates environmental, behavioral, physiological events. present study performed concurrently an ecological-behavioral (Erpino 1968b) attempt to determine gonadal behavior nonmigratory magpie population near Laramie, Wyoming. Ovarian histology accorded special attention this paper because characteristics seasonal ovarian changes these are poorly understood (Marshall 1964; 1966). While yolk formation has been studied periodic