Sperm-storage glands in a passerine: the zebra finch Poephila guttata (Estrildidae)



Sperm-storage glands in the zebra finch are described; the first passerine for which such information is available. Sperm-storage glands occurred only in paired females, and were located in folds throughout the vagina and on the vaginal side of the utcro-vaginal region. Mean dimensions of the glands were: internal diameter 17·5 μm and length 254 μm; these values are similar to those found for two other (much larger) bird species. The need for passerines to possess sperm-storage glands is discussed.