Oestrogen stimulation of nest material preparation in the peach-faced lovebird ( Agapornis roseicollis)

Abstract

The purpose of this study was to determine whether the behaviour involved in nest material preparation by female Agapornis roseicollis is stimulated at least in part by an oestrogen and at what age this behaviour can first be induced with an exogenous hormone. A pilot study indicated that an oestrogen (diethylstilbestrol) can stimulate nest material preparation, but only after the female has reached a certain minimum age. A second experiment, using a single cross-over design, was made to determine this age. Four 10-week-old females received oestrogen pellet implants; four others were given control pellets. After 9 weeks the treatments were reversed, the control birds now receiving oestrogen. Measures of the treatment effects were the number of strips cut from paper sheets and the area of paper left uncut. The treated birds showed nest material preparation beginning in the 3rd week of treatment, peaking at weeks 6 and 7 and decreasing in weeks 8 and 9. The control birds showed almost no nest material preparation until after treatment reversal. These responses indicate that preparation of nest material in A. roseicollis is mediated at least in part by oestrogen and that immature females can be stimulated to this activity at least 2 weeks before they would normally begin.