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Abstract: With many of the world's migratory bird populations in alarming decline, broad‐scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light‐polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi‐year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly‐lit sources. This finding implies broad‐scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high‐quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations. [ABSTRACT FROM AUTHOR]

We used capture-recapture methods to estimate bird species richness from mist-net and point-count data from a study area in Campeche, Mexico. We estimated species richness separately for each survey technique for two habitats, forest and pasture, in six sampling periods. We then estimated richness based on species' detections by either technique, and estimated the proportion of species detected by each technique that are not part of the population sampled by the other technique. No consistent differences existed between richness estimates from count data and from capture data in the two habitats. In some sampling periods, over 50% of the richness estimate from one survey technique may be species that are not sampled by the other technique, suggesting that one technique may not be adequate to estimate total species richness and that comparing estimates from areas sampled by different techniques may not be valid. [ABSTRACT FROM AUTHOR]

Models predicting the occurrence of area-sensitive bird species in forests were developed from bird survey data from 499 forests in Prince George's County, Maryland. The predicted probabilities of occurrence for species were integrated with forest cover data for the County in a Geographic Information System (GIS). This information was used incombination with local zoning and forest conservation requirements to develop a preliminary forest conservation plan for the watershed ofthe Western Branch of the Patuxent River. We identify forests patches most likely to support breeding populations of area-sensitive birds, and use the GIS to devise ways to consolidate and link them. Forests that do not contribute significantly to the integrity of these priority forests are designated as sites in which development could occur. The resulting conservation plan will maintain and enhance breeding habitat for area-sensitive forest birds, while still allowing for additional development as human populations increase. [ABSTRACT FROM AUTHOR]