Semen quality in captive Houbara bustard, Chlamydotis undulata undulata

Semen quality in captive-bred Houbara bustards, Chlamydotis undulata undulata, was assessed during three consecutive breeding seasons. In any one season, sperm quality, in terms of the proportion of eosin-permeable spermatozoa and of spermatozoa with abnormally large nuclei, varied among individual males, but not among their ejaculates. Neither the proportion of spermatozoa with large nuclei, nor those permeable to eosin were related to the total sperm output of males. The fertilizing ability of males was related to their mean seasonal proportion of eosin-permeable spermatozoa, but not the proportion of spermatozoa with large nuclei. The ranking of males on the basis of the proportion of spermatozoa with large nuclei in their ejaculates was significantly positively correlated between seasons, although ranking on the basis of sperm eosin-permeability was not. The cause or consequence of producing spermatozoa with large nuclei (and excess DNA) remains to be elucidated, but appears to be a trait that is characteristic of Houbara bustard males that is maintained between breeding seasons.