Abstract
Annual testicular activity was investigated in the Indian Tree Pie Dendrocitta vagabunda by studying the testis once a month throughout the year. The investigation revealed that testicular activity showed a distinct annual cycle consisting of four phases: nonbreeding (August to January); progressive (February and March); breeding (April and May); and regression (June and July). The testis weight, seminiferous tubular area and germ cell population were low during the nonbreeding phase, increased during the progressive phase, peaked during breeding and declined afterwards. But the sertoli cell population increased during the nonbreeding phase and decreased in the early breeding phase (April). The Leydig cells were large during the early breeding phase compared to other phases of the cycle. Cholesterol and ascorbic acid levels in the testis were highest during the nonbreeding phase, decreased moderately during the progressive phase, became lowest during the early breeding phase and began to rise thereafter. But acid phosphatase, alkaline phosphatase, sialic acid, RNA and protein content changes of the testis were the reverse. The findings indicate that the Indian Tree Pie has a single peak of spermatogenic activity in a year during April and May. Steroidgenic activity of the testis also varies with the spermatogenic cycle, but it appears to reach its peak slightly earlier in April than that of spermatogenic activity in this species.
