Bachman's Sparrow - Timing of Major Life Events - Nesting Success

Nesting Success

Values of nest success reported for Bachman's sparrows vary. Daily nest survival rate of Bachman's sparrow ranged from 0.89 to 0.96 across sites and years in the dry prairie of central Florida. On average 3.13 birds were fledged per successful Bachman's sparrow nest. Estimates of productivity ranged from 1.21 to 4.16 offspring per pair per year across sites and years. In a South Carolina longleaf pine community, daily survival rate of Bachman's sparrow nests in 1995 was 0.952, which was significantly (p=0.04) higher than the 1996 daily nest survival rate of 0.889. Earlier nesting attempts (before June 15, n=15) had significantly (p=0.05) higher survival rates than those started later in the year (n=11). Daily nest survival rate was 0.922 during incubation and 0.973 during the nestling stage. In central Arkansas, daily success rate during the incubation period was 0.965, while in the nestling period it was 0.919. In the glades of south-central Missouri, 8 female Bachman's sparrows fledged an average of 1.5 young per season over 2 years. Predation accounted for 80% of egg loss on study sites in Arkansas and 94% of nest failures on sites in central Florida. Information on Bachman sparrow nest predators can be found in the Predators section of this summary. Cowbirds and nest abandonment were the other known causes of nest failure.