Treesearch

Conservation of species associated with mature forest habitats remains an important objective for non-federal lands in the Pacific Northwest. With few exceptions, state forest practices rules, a Washington state pilot landscape planning program, and federal Habitat Conservation Plans provide little functional habitat for species, like the Pileated Woodpecker (Dryocopus pileatus), that are associated with mature forest structures such as large-diameter snags and defective trees. At the beginning of the new millennium, millions of hectares of non-federal forest lands in western Washington...

The Garry oak (Quercus garryana) ecosystem was once a dominant habitat type on southeastern Vancouver Island, British Columbia, but urbanization has lead to massive habitat loss and fragmentation (Hebda 1993). Most bird species are expected to respond negatively to urbanization because of increased patch isolation, increased predation pressure, and negative edge effects (Marzluff and Ewing 2001). On southeastern Vancouver Island, Garry oak remnants form a mosaic along with coastal Douglas-fir (Pseudotsuga menziesii) forests. Since the two ecosystems differ in habitat structure and compositi...

Environmental protection policies sometimes protect forests along an advancing suburban front although many of the forests may be brought into close proximity to residential housing. Research suggests that even when forests are physically preserved, their bird communities are simplified as the surroundings become urbanized. However, little is known of the time required for these changes to appear or of the mechanisms that drive them. We obtained population measures on the Wood Thrush (Hylocichla mustelina), an urban-sensitive woodland species in at least portions of its breeding range,...

The Dominican Republic, on the island of Hispaniola, supports more bird species than any other Caribbean country except Cuba. More than 300 species of birds have been recorded in the country, including 285 native residents and 27 endemics (Keith et al. 2003). The Dominican Republic is also a major wintering site for Neotropical migrants. Despite this ichness, the avifauna is perhaps the least studied in the Greater Antilles and is under increasing pressure from habitat alterations, hunting, trafficking of birds for the pet trade, pollution, and other effects of the human population....

Our understanding of the ecology and conservation of migratory birds has changed dramatically in the past 25 years. In the Smithsonian symposium of 1977, scientists shifted from the idea of North American birds invading the tropics to that of tropical birds using the temperate zone, with little mention of conservation. By the Manomet meeting of 1989, declines on the breeding grounds led to our focus on conservation and answering, "Where have all the birds gone?" The first Partners in Flight meeting in 1992 had a strong management focus and provided much of the theory used in PIF bird...

Migratory birds are birds of two worlds, breeding in the temperate zone then living as tropical birds for most of the year. We show two aspects of this unique biology that are important considerations for their conservation. First, habitat selection for breeding must include their need for extra-pair mating opportunities. Second, non-breeding distributions in tropical latitudes are poorly known. Both geographic distribution and over-wintering habitat are much more limited than generally thought, suggesting that many species may be in more danger of population limitation there than presently...

Forest fragmentation, urbanization, and forest management are important issues for bird conservation in the eastern broadleaf forest of North America. Fragmentation of forest by agricultural and developed land uses increases the numbers of Brown-headed Cowbirds (Molothrus ater) and nest predators in the landscape, which results in decreased productivity of songbirds. Reproductive success is so low in some Midwestern landscapes that the only way populations could persist is through immigration, which provides circumstantial evidence that populations are structured as sources and sinks....

We used fixed-distance point counts to monitor bird populations from 1994-1998 in a rapidly urbanizing region of southwestern Missouri. Prior to the early 1990s, the rural landscape was a mosaic of forest, dolomite glades, and pasture but development proceeded rapidly in the 1990s with increased promotion of Branson, Missouri as a vacation and retirement destination. Point count data were collected in areas with native vegetation intact and that are not likely to be developed as the region continues to urbanize (undeveloped sites), and at a 375-ha residential/golf development (developed...

I compared avian species richness, density, and diversity for neotropical migrants, short distance migrants, and permanent residents following timber harvesting in cove hardwood forests in the Southern Appalachian Mountains of North Carolina. The forest stands were 4-103 years old, had undergone a clearcut or selective tree removal, and represented four successional stages (early, sapling/pole, mid, and late). Neotropical migrants constituted 60.5 to 69.0 percent of species richness. Mean breeding bird density for all species was 225.1 pairs/40 ha (±16.3 se) with an overall mean density...

The Arkansas Ozarks are currently experiencing an outbreak of the red oak borer (Enaphalodes rufulus), a native insect that has previously not been considered an important forest pest species. As many as 50 percent of the trees in the Ozarks, which has the highest density of oaks in the United States, may be dead by the year 2006. The Ozarks are generally believed to be a source region for Neotropical migratory birds, compared to fragmented areas to the east and north, but that could change very rapidly with the elimination of oaks. The potential impact on migratory breeding birds was...