Morphology of the pineal body of wild house sparrows (Passer domesticus) in relation to reproduction and age

Abstract

The pineal bodies of wild English or house sparrows (Passer domesticus) were examined histologically for evidence of morphological changes with respect to seasonal reproductivity, sexual maturation, and age. No correlation of changes in the appearance of the pineal of either sex was found with time of year or with size of gonads. However, it was observed that the pineal changed during the bird's first 90 days from a loose, highly folliculated body to a compact, more solid-appearing structure. Area measurements of median sections indicated that the size of the pineal body tended to decrease with an increase in age from 30 to 180 days.