| SEASONAL BREEDING IN THE ITALIAN SPARROW: PLASMA ANDROGEN LEVELS AND SPERMATOGENESIS |
DOMENICO FULGIONE A1, DANIELA RIPPA A1, MARIA FILOMENA CALIENDO, A1, MARIO MILONE A1
A1 Department of Biological Science, Section of Zoology, University of Naples Federico II, via Mezzocannone 8–80134 Naples, Italy
In this research we studied the spermatogenesis and circulating androgen levels in the male Italian sparrow. A seasonal pattern is shown, and evidence is provided that the Italian sparrow has multiple-clutch breeding activity. In particular, we have observed a winter resurgence of testicular activity, as indicated by active spermatogenesis and a relatively higher plasma androgen level as compared to the summer hormone levels. No breeding males were ever observed during the winter period, and an apparent resurgence of gametogenesis may simply be considered as a transient phenomenon. We suggest that multiple-clutch breeding activity and transient winter resurgence of spermatogenesis reflect the derivation of this species from an ancestral population, probably the progenitors of P. hispaniolensis, spread from Africa to the Italian peninsula.
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