July - September 2009, Volume 5, Issue 3

Bharucha B, Padate GS

Cyclic variations in the levels of testosterone and progesterone in male and female during different phases of breeding in house sparrow (Passer domesticus)

Acta Endo (Buc) 2009, 5 (3): 317-327
doi: 10.4183/aeb.2009.317

Background and Aim. The house sparrow (Passer domesticus) is a seasonal breeder\r\nforming monogamous pairs like majority of the sub-tropical birds. Less is known about its\r\nreproductive endocrinology during different phases of the breeding cycle. In the present\r\nstudy, the house sparrows were analysed to shed light onto their breeding physiology.\r\nMethods. Seasonal changes in body weight, gonad morphology and plasma\r\nconcentration of testosterone and progesterone (by ELISA) were evaluated in 40 males and\r\n40 females respectively, using 10 birds for each season.\r\nResults. Testosterone in males was minimal during the non-breeding phase at 0.41 ? 0.17\r\nng/mL increasing at 2.35 ? 0.12 ng/mL during the onset of the pre-breeding phase,increased in the\r\nbreeding period at 5.65 ? 0.16 ng/mL, while in the post-breeding phase it was 3.83 ? 0.20 ng/mL.\r\nIn females, testosterone levels during the non-breeding phase were 0.11 ? 0.07 ng/mL, which rose\r\nsignificantly during the pre-breeding phase to 0.45 ? 0.10 ng/mL, a level equivalent to the one in\r\nmales during the non-breeding phase. During the breeding phase the values increased to 1.25 ?\r\n0.09 ng/mL, which later decreased in the post-breeding phase to 0.96 ? 0.12 ng/mL.\r\nProgesterone basal levels in females during the non-breeding phase were maintained at\r\n1.80 ? 0.10 ng/mL. A significant increase (p<0.001) is seen with the onset of pre-breeding\r\nphase which continues in the breeding phase at 2.20 ? 0.13 ng/mL and 6.23 ? 0.12 ng/mL,\r\nrespectively. During the post-breeding phase the levels significantly (P<0.001) decreased to\r\n4.73 ? 0.10 ng/mL. In males, the levels of this hormone vary less during all the phases of\r\nbreeding. The progesterone titres during the non-breeding phase were 0.85 ? 0.17 ng/mL\r\nincreasing with the onset of the pre-breeding season at 1.12 ? 0.13 ng/mL and continued to rise\r\nin breeding phase at 2.76 ? 0.16 ng/mL. Later during the post-breeding phase the levels\r\ndecreased significantly 1.45 ? 0.18 ng/mL (p<0.001).\r\nConclusion. The present study reveals cyclicity in the breeding and cyclic changes taking\r\nplace in the titers of the two hormones during different phases of the breeding in both sexes.

Keywords: solitary seasonal breeder, testosterone, progesterone

Correspondence: Bharucha Bhavna, Ph.D., Department of Zoology, Faculty of Science, The M.S. University of Baroda, Vadodara, Gujarat, India, Tel. 0265-390117, E-mail: cyprea_bb@yahoo.com