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The components that are influencing the population of several bird species in riverbank regions of northeastern Missouri regions in the United States are examined.

The factors that are affecting breeding densities of songbird in Missouri are examined by using information-theoretic approach based on forest regeneration, glade and habitant types.

Research on indigo bunting and field sparrow songbird populations indicates that nest height is the single, most consistent microhabitat variable affecting predation ratios, as nests more than 3 m high had the highest fledgling rates. Other microhabitat variables tested were time of season, weather, brood parasitism and nesting cycle stage.

Research on Bell's vireo populations in central Missouri indicates that increasing large shrub patch density is the best method to improve nest success for the species. Studies were conducted on brood parasitism and nest predation rates on Bell's vireo by brown-headed cowbirds.

Studies in the Missouri Ozark shrublands show that bird population responses to the effects of habitat edge, or boundaries, are species-specific, and do not correspond to responses demonstrated by forest birds. The studies also showed that shrubland habitat edges did not become ecological traps, however, as habitat selection was not correlated to nest predation.

Agricultural lands and edges are valuable to raccoons in both landscape and local scales. This research, undertaken on 25 scent-station routes across Missouri, investigated the connection between landscape composition, structure and latitude and the relative abundance of raccoons, striped skunks and opossums. At a landscape scale, raccoons were more abundant in agricultural landscapes with high densities of streams than in forested landscapes with low densities of streams. It was possible to identify potentially significant relationships between relative abundance of predators and forest edges.

There is increasing concern about the effect of land management and use on the forest songbird population. A study of breeding songbird populations in a hardwood forest in southeastern Missouri was aimed at discovering the effect of four different types of forest harvesting. Among the 14 species examined were migrant songbirds, including the prairie warbler, white-eyed vireo and blue-winged warbler. The results show that the abundance of each species depends on the abundance of their habitat and suggest that forest management should ensure that forest fragmentation is avoided.

Concern has arisen that forest management practices that create edge (such as clearcutting) are contributing to regional declines in neotropical migrant birds that inhabit forest interiors. Consequently, we studied breeding bird populations in an extensively forested region of southern Missouri to determine if the numbers of breeding birds differed between areas (n = 9) managed by the clearcutting method (CCM), and areas (n = 9) of mature forest with no recent timber harvest or other disturbances (NOHVST). Three forest interior migrants had lower (P < 0.06) mean densities on CCM sites than NOHVST sites: 3 had greater (P < 0.03) densities on CCM sites; and densities of 3 others did not differ (P > 0.40) between treatments. All early successional migrants had greater (P < 0.01) densities on CCM sites. Numbers of 2 avian nest predators and a brood parasite did not differ (P > 0.20) on CCM and NOHVST sites. Densities of 9 species differed (P < 0.10) among regeneration, sapling, and pole-sawtimber habitats on CCM sites. While clearcutting reduced numbers of forest interior birds that were dependent on mature forest habitats, other forest interior species made extensive use of early and mid-successional even-aged stands and occurred in greater numbers on CCM sites.

Landscape habitat suitability index (HSI) software can be used for the evaluation of suitability of a habitat for 21 wildlife species. Landscale HSImodels are applied to forest-simulation model output, thus providing managers a tool to contrast the effects of forest management practices with current habitat quality for a variety of wildlife species.

The net-site selection by black-capped vireos is analyzed by using a regression model and landscape scale design. The multiscale net-site selection different species of oak forests was observed in these species.

Research on songbird nest predation in central Missouri is presented. Predation by snakes was higher than by mammals in old fields, while predation by mammals was higher than by snakes in forest habitats. Predation rates were not affected by the presence or absence of wildlife observation cameras.

We described habitat preference, home range, daily movement, and survival of territorial male ruffued grouse (Bonasa umbellus) in a central Missouri forest. The study area was primarily forested with oak (Quercus spp.)-hickory (Carya spp.) pole and sawtimber (63%), and mixed sapling to pole-size eastern red cedar (Juniperus virginiana) and hardwoods (16%). One to 4-year old clearcuts comprised 2% of the area. We instrumented 32 territorial male grouose with radio transmitters and obtained a mean of 55 locations/grouse. Ruffed grouse did not show strong habitat preference in locating their home range, but within home ranges grouse strongly preferred mixed cedar-hardwoods during spring-summer and fall-winter. Survival was 0.350, 0.486, and 0.721 for annual, fall-winter, and spring-summer, respectively. Harmonic mean estimates of fall-winter and spring-summer home range were 104 and 67 ha, respectively. Mean daily movement during fall-winter and spring-summer was 392 and 263 m, respectively. Home range and mean daily movement differed significantly between spring-summer and fall-winter. Survival rates were inversely related to seasonal home-range size and mean daily movement.

A review of the different types of semi-wooded, early successional habitat in the eastern US is presented, focusing on habitats dominated by shrubs, saplings, forbs and grasses, interspersed with mature trees.

Research describing the effects of forest management on song birds is presented. Key features of experimental design and and scientific enquiry are reviewed and their application to songbird studies is assessed.