Abstract1. Non-random mating was observed in captive Burmese Red Junglefowl (Gallus gallus spadiceus) in three experimental situations. 2. When eight cocks were released singly for short periods (one hour) with each of two female flocks it was found that, in one flock, crouching and the coition incidence were non-random; the distribution of female crouching exerted only a limited effect on the distribution of copulations. 3. A quantitative analysis of the courtship of these males revealed that the correlation between differences in male courtship and the distribution of crouching was of an incomplete nature. The cock which elicited most crouches, R, also performed more crouch-evoking displays than other males. Other factors were also important in effecting non-random crouching by females. 4. In a heterosexual flock with four resident males there was a strong correlation between male dominance status and sexual activity. Only the top ranking cock interfered with other males' matings, his own matings being undisturbed. The result was non-random mating, in which only the alpha cock copulated. 5. When the number of males was increased to six, interference was not restricted to the alpha cock and several of his attempted matings were disturbed. This was due to increased sexual excitement through social facilitation, and the net result was a reduction in copulatory activity, effecting random-mating. It was further found that non-random female crouching occurred, the second ranking cock eliciting significantly more sexual crouches than any other male. 6. In two female flocks with single resident males, some elements of male courtship activity were non-randomly distributed amongst the females. In flock II female crouching behaviour exerted a strong affect on male courtship activity, but this was not the case in flock 1. The difference was attributable to a different level of sexual vigour between the two males. 7. The basis of non-random courtship by the males is obscure but is probably based on differences in female behaviour. It is misleading to regard this phenomenon as male "preference" for individual females, it is better categorised as a response to signals irrespective of the identity of the 'signaller'. 8. The occurrence of non-random mating in wild gallinaceous species, particularly those exhibiting a 'lek' courtship, is discussed briefly. Some tentative parallels are drawn with the present work. 9. The present results are very similar to those obtained by several authors for the domestic fowl, which has a very similar social behaviour repertoire.
Courtship behaviour influences social partner choice in male guppies