Skip to main content
Figure 5 | Frontiers in Zoology

Figure 5

From: Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

Figure 5

Mean (±SE) testis volume of male house sparrows (n = 9–10) subjected for 17 weeks to photoperiods with increasing lengths of daily light periods. a: 2L:22D, 6L:18D and 10L:14D. A slow and small testicular response occurred in 2L and 10L, but not in 6L photoperiod, except that 2 of 7 birds in this group showed small initiation at the end of the experiment. b: 14L:10D, 18L:6D and 22L:2D. A faster induction of testicular growth occurred in 22L, but regression was almost the same in all three photoperiods. Asterisk shows significant difference between 22L and 18L or 14L groups.

Back to article page