Factors influencing bird-building collisions in the downtown area of a major North American city.

Bird-building collisions are the largest source of avian collision mortality in North America. Despite a growing literature on bird-building collisions, little research has been conducted in downtown areas of major cities, and no studies have included stadiums, which can be extremely large, often have extensive glass surfaces and lighting, and therefore may cause many bird collisions. Further, few studies have assessed the role of nighttime lighting in increasing collisions, despite the often-cited importance of this factor, or considered collision correlates for different seasons and bird species.

Bird-building collision risk: An assessment of the collision risk of birds with buildings by phylogeny and behavior using two citizen-science datasets.

Bird collisions with buildings are the second largest anthropogenic source of direct mortality for birds (365-988 million birds killed annually in the United States). Recent research suggests that this mortality occurs disproportionately across species. However, previous work had relied on regional and annual measures of relative species abundance.

The unseen invaders: introduced earthworms as drivers of change in plant communities in North American forests (a meta-analysis).

Globally, biological invasions can have strong impacts on biodiversity as well as ecosystem functioning. While less conspicuous than introduced aboveground organisms, introduced belowground organisms may have similarly strong effects. Here, we synthesize for the first time the impacts of introduced earthworms on plant diversity and community composition in North American forests.

Reduced density and nest survival of ground-nesting songbirds relative to earthworm invasions in northern hardwood forests.

European earthworms (Lumbricus spp.) are spreading into previously earthworm-free forests in the United States and Canada and causing substantial changes, including homogenization of soil structure, removal of the litter layer, and reduction in arthropod abundance and species richness of understory plants. Whether these changes affect songbirds that nest and forage on the forest floor is unknown.

Cross-taxonomic potential and spatial transferability of an umbrella species index.

Validation that conservation of certain species effectively protects a high proportion of co-occurring species is rare. Our previous work has suggested that an umbrella index based on geographic distribution and life history characteristics would maximize the proportion of conspecifics protected per unit area conserved. Using bird and butterfly data from three mountain ranges in the Great Basin, we examined whether umbrella species also would confer protection to species in different taxonomic groups.

Nestedness analysis and conservation planning: the importance of place, environment, and life history across taxonomic groups.

We used nested subsets analysis to examine distribution patterns of birds and butterflies in the same set of 83 locations in canyons of three mountain ranges in the Great Basin of western North America. We tested whether the same environmental variables influenced nestedness among taxonomic groups and among mountain ranges within taxonomic groups. We also examined whether nestedness of birds and butterflies appeared to be sensitive to human use of riparian areas in the ecoregion.