REPRODUCTIVE SUCCESS OF POLYGYNOUS MALE CORN BUNTINGS (MILIARIA-CALANDRA) AS CONFIRMED BY DNA-FINGERPRINTING

Despite a sex ratio approximating to unity, female corn buntings were not equally distributed among males. In 1989 and 1990, 41.2% of 50 mal es were monogamously paired, 29.4% were polygynous, and 23.5% were unp aired. Polygynous males usually paired with two females, although in 1 990 three males were trigamous. Polygynous males fledged more offsprin g from their territories than did monogamous males, mainly because the y had more mates. The fledging success per nesting female was slightly higher in territories of polygynous males, but not significantly so. DNA fingerprinting was used to confirm the true paternity of 44 offspr ing from 15 broods and the true maternity of 50 offspring from 16 broo ds. A further 12 offspring from three broods for which neither putativ e parent was available were also finger-printed. Actual reproductive s uccess of parents was close to that inferred from observations of numb er of young raised. There was only one brood, containing two chicks (4 .5% of offspring, or in 6.7% of broods), where the chicks were not fat hered by the male defending the territory. However, this nest was clos e to the territory boundary, and the defending male may have been assi gned incorrectly. There were no cases of intraspecific brood parasitis m (n = 16 broods). The copulation rate was low, and extrapair copulati on attempts were rare, probably because of the poor chances of sneakin g onto a neighbor's territory undetected and the costs of leaving a te rritory unguarded.