North American birds that feed on aerial insects are experiencing widespread population declines. An analysis of the North American Breeding Bird Survey trend estimates for 1966 to 2006 suggests that declines in this guild are significantly stronger than in passerines in general. The pattern of decline also shows a striking geographical gradient, with aerial insectivore declines becoming more prevalent towards the northeast of North America. Declines are also more acute in species that migrate long distances compared to those that migrate short distances. The declines become manifest, almost without exception, in the mid 1980s. The taxonomic breadth of these downward trends suggests that declines in aerial insectivore populations are linked to changes in populations of flying insects, and these changes might be indicative of underlying ecosystem changes

Recent population trends of Ontario's forest birds were assessed by integrating results across 8 bird surveys to provide an estimate of trend status for all of Ontario, and for 2 forested regions of Ontario separately. Surveys with mid-and longterm trends were relied on most extensively in this assessment. Comparison of the first and second Breeding Bird Atlases was especially important for estimating trends in northern forests, but overall reliability of status assessments in the north was considered poor due to limited coverage and significant potential for bias. Trends of most forest birds were stable or positive at the Ontario-wide scale, with trends at least as positive as forest birds elsewhere in North America, and showing more positive trends overall than birds of agricultural landscapes. Nevertheless, individual species trends ranged from large declines to large increases, and several forest birds have been added to Species at Risk lists largely because of population declines. There were few differences in trend status among forest birds grouped by habitat association or migratory guild, although all 5 aerial insectivore species have declined. Better monitoring coverage of the boreal will be needed if improved reliability of trends is desired in the near future.Key words: Ontario, forest birds, boreal forest, population trend, bird surveys, monitoring reliability RÉSUMÉLes fluctuations récentes des populations d' oiseaux forestiers de l'Ontario ont été évaluées au moyen de l'intégration des résultats de 8 relevés d' oiseaux pour produire un estimé de la tendance actuelle pour tout l'Ontario ainsi que particulière-ment pour 2 régions forestières de la province. Les relevés indiquant les fluctuations à moyen et à long terme ont fait l' objet d'une utilisation plus poussée pour cette évaluation. La comparaison entre le premier et le second atlas des oiseaux nicheurs a été particulièrement importante pour pouvoir estimer les fluctuations dans les forêts boréales, mais la fiabilité générale des tendances actuelles dans le nord de la province a été jugée faible compte tenu de la couverture restreinte et du potentiel significatif de biais. Les fluctuations de la plupart des populations d' oiseaux forestiers se sont révélées être stables ou positives pour l' ensemble de la province, ces fluctuations étant au moins aussi positives par rapport aux oiseaux forestiers ailleurs en Amérique du Nord et elles étaient encore plus positives dans l' ensemble par rapport aux oiseaux des milieux agricoles. Néanmoins, les fluctuations des espèces individuelles variaient entre des déclins importants et des accroissements majeurs et quelques oiseaux forestiers ont été ajoutés à la liste des espèces en péril principalement suite à un déclin des populations. Peu de différence a été relevée pour ce qui est des tendances chez les oiseaux forestiers regroupés en fonction de leur habitat ou de leur regroupement migratoire, même si 5 espèces insectivores se nourrissant en vol sont en déclin. Une meilleure étude des territoire...

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We examined nest-site selection by hooded warblers (Wilsonia citrina) in two forests differing in composition (extensive pine plantation versus largely deciduous) and management (recent selective logging versus minimal logging). We measured habitat at 52 nests and 66 controls in one forest and 57 nests and 41 controls in the second. Nests had denser ground vegetation, fewer tree stems, less basal area due to small trees and greater basal area due to large trees than controls in both forests. In the managed forest with extensive pine plantations, hooded warblers were in coniferous and logged stands more often than expected by chance, nests had more stumps and greater canopy height than controls, and 91% (52/57) of all nests were found in gaps, 84% of which were created by harvest. Gap age was 6.2 ± 0.9 years (mean ± SE) in 1999, and 7.6 ± 0.6 years in 2000. In the managed forest, 52% of 24 nests were parasitized in 1999 and 39% of 33 nests were parasitized in 2000. The daily survival rate was 0.936 ± 0.019 in 1999 and 0.944 ± 0.014 in 2000. Successful nests did not differ from unsuccessful nests in any habitat variable. To benefit hooded warblers, forest managers should mimic natural gap creation by using selective logging to create gaps no larger than 0.05 ha, and should leave a residual basal area of mature trees (>38 cm diameter at breast height) of at least 12 m2/ha.