A critical step in understanding the relationship between forest management and bird populations is conducting studies that employ rigorous experimental designs, relate forest management to avian demography, and explore relationships at expanded temporal and spatial scales. The Missouri Ozark Forest Ecosystem Project ( MOFEP ) is a long‐term, large‐scale manipulative experiment that is testing the effects of even‐aged ( i.e., clearcutting ) and uneven‐aged ( i.e., selection cutting ) forest management on a suite of response variables in Missouri oak‐hickory forests. We report on the short‐term effects of these management systems on the density and reproductive success of birds by evaluating 5 years of preharvest and 3 years of postharvest data from MOFEP. Densities of mature forest species declined 24–69% on the control ( i.e., no timber harvest ) sites during post‐treatment years, confounding interpretation of treatment effects. Densities of both Kentucky Warblers ( Oporornis formosus ) and Worm‐eating Warblers ( Helmitheros vermivorus ) increased in treatment sites relative to control sites. Conversely, even‐aged management negatively affected Ovenbird ( Seiurus aurocapillus ) density. Treatment significantly and positively affected density of four of the six early successional species. Densities of Indigo Bunting (  Passerina cyanea ) and Yellow‐breasted Chat (  Icteria virens ) were significantly higher in both even‐aged and uneven‐aged treatments, whereas densities of Prairie Warbler (  Dendroica discolor ) and White‐eyed Vireo (  Vireo griseus ) were significantly higher in even‐aged treatments than in the controls. Nest success rates averaged 29% for all species and did not change significantly from pre‐ to post‐treatment years. Mature forest bird populations declined as trees were removed, but significant changes in nest predation and brood parasitism did not occur. In addition, openings associated with timber removal provided habitats for early successional species. We suggest that a mixed strategy of timber management may be necessary to support the full range of breeding birds in this region.

From 1992–1995, we compared the season‐long fecundity of marked Ovenbirds ( Seiurus aurocapillus) on three sites in large ( >2000‐ha) forest patches in a fragmented landscape in central Missouri (U.S.A.) with four sites in a contiguously forested landscape of almost 2 million ha in the Missouri Ozarks. Our purpose was to determine to what extent the negative effects of fragmentation on nests affect individual bird's annual productivity. To measure annual productivity, we determined the proportion of territorial males that ultimately succeeded in raising young in a season and multiplied this proportion by the average brood size obtained from nest observations. Fewer pairs successfully raised young in the fragmented landscape (50 ± 11%) than in the unfragmented landscape (70 ± 7%). In the fragmented landscape, 25 ± 6% of pairs raised at least one Brown‐headed Cowbird ( Molothrus ater), whereas only 1 ± 1% of pairs raised cowbirds in the unfragmented landscape. Lower season‐long success and increased brood parasitism led to annual productivity of 0.70 and 1.47 juvenile females per female in the fragmented and unfragmented landscapes, respectively. Territory size (mean = 2.76 ha) was not affected by landscape, but density was lower in the fragmented landscape (1.6 ± 0.41 males per 10 ha) than in the unfragmented landscape (2.2 ± 0.32). The ratio of second‐year to after‐second‐year males did not vary with landscape. Male pairing success (67 ± 6%) and survival (0.621 ± 0.21) was not affected by landscape. We concluded that it was unlikely that sites in the fragmented landscape contained viable Ovenbird source populations, whereas populations in the unfragmented Ozark region were likely to be sources in most years. Nevertheless, any changes in the Ozarks that increase nest predation or parasitism may have consequences for the regional population of Ovenbirds and other forest‐breeding Neotropical migrants in the midwest.

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