Endocrine Aspects of the Annual Reproductive Cycle in the Starling (Sturnus Vulgaris) |
Common terms and phrases
abundance activity additional amount annual aspects assay avian begins behavior bill birds breeding season brood cause cells centers changes collection competitive condition considerably continues correlated cycle determinations diameter differences effect eggs elevated endocrine estrogen evidence exist factors fall Farner female female Starlings Figure final follicles FSH secretion functional gland gonadal growth hormones important increase indicate interstitial interstitial cells July known largely levels LH secretion light Lofts maintained male Starlings March Marshall maturation mean measured mechanism minutes nature nest occurring organs ovarian ovary oviduct ovulation peak period photoperiods photorefractory pituitary gonadotropin content plasma points represent possible present production prolactin reached recovery refractory relationship release remains reproductive response result sample Seasonal variation seems seminal sacs seminiferous tubules sexual stages standard stimuli suggest testes testicular testosterone titers Tienhoven tube values van Tienhoven weight winter yearly cycle