Plasma luteinizing hormone in male ring doves during the breeding cycle

Plasma levels of LH were analyzed in male ring doves throughout a breeding cycle. LH levels were low in visually isolated animals [(8.0 ± 1.6 ng/ml) (X ± SE)], peaked the day after pairing with a female (14.3 ± 2.52 ng/ml), and declined to baseline levels during incubation and brooding. If eggs or squab were removed during the period of parental care, LH levels rose. The increase in LH following removal of eggs was more prolonged in late incubation than in early incubation. We conclude that the female enhances while the young (eggs or squab) suppress LH in male ring doves.