Unlike resident bird species, the population sizes of migratory species can be influenced by
conditions in more than one part of the world. Changes in the numbers of migrant birds …

The influence of area and vegetation structure on breeding bird communities associated
with 24 Illinois grassland fragments (0.5—600 ha) was studied between 1987 and 1989 to …

Many species of birds that depend on grassland or savanna habitats have shown
substantial overall population declines in North America. To understand the causes of these …

ECOLOGY Population status of North American grassland birds from the North American
Breeding Bird Survey, 1966-1996................................................. Bruce G. Peterjohn and John …

An extensive road system with rapidly increasing traffic produces diverse ecological effects
that cover a large land area. Our objective was to evaluate the effect of roads with different …

There is growing evidence that many species of birds have declined throughout the eastern
United States during the past 40 years. In many cases this decline involves groups of …

We used multiple and logistic regression analysis to study the breeding‐area requirements
of 10 species of grassland and early‐successional birds at 90 grassland‐barren sites in …

Most species occupy both high‐and low‐quality habitats throughout their ranges. As habitats
become modified through anthropogenic change, low‐quality habitat may become a more …

Agriculture probably has had greater impact on populations of Neotropical migratory birds
than any other human activity. Although crop types differ greatly among regions, most …

Bird use of Conservation Reserve Program (CRP) and row-crop fields was studied in central
Iowa from May through July 1991-1993. Thirty-three bird species were recorded in CRP …