ROLE OF GONADOTROPHIN RELEASING HORMONES IN THE REPRODUCTIVE BEHAVIOUR OF FEMALE RING DOVES (STREPTOPELIA RISORIA)

Abstract

This work was carried out to determine whether gonadotrophin releasing hormone(s) (GnRH) plays a role in the courtship behaviour of female ring doves. In particular, it tests the hypothesis that a high dose of oestrogen suppresses the synergistic action of GnRH with oestrogen which is required to elicit courtship behaviour. The hypothesis was formulated to provide an explanation for a finding in a previous study that ovariectomized ring doves treated with a high dose of oestrogen, paradoxically, failed to show courtship behaviour. In the present study, treatment with synthetic LH releasing hormone (RH) enabled such birds to show typical female behaviour, thus supporting the hypothesis. This LH-RH effect was not apparently mediated by LH or progesterone since treatment with LH or progesterone failed to induce courtship behaviour. In addition, LH-RH can synergise with sub-threshold doses of oestrogen to induce both nest-soliciting and squatting behaviour. This portion of the LH-RH effect complements similar results reported for the rat. Finally, the results of thyrotrophin releasing hormone point to the specificity of LH-RH and the results of an anti-ovulation LH-RH analogue agree with the LH-RH effect.