Browsing by Subject "Neotropical migrant birds"

Now showing 1 - 5 of 5
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    Bird and Herpetofaunal Inventory on St. Louis County Lands
    (University of Minnesota Duluth, 1998) Montgomery, Kent; Niemi, Gerald J
    Neotropical migrant birds have recently received much attention following reported declines in many species that breed in eastern North America. Probable causes for such declines include events such as habitat alteration, occurring on both breeding and wintering grounds. Changes in forest species composition and age structure, and the spatial arrangement of these forest components may influence bird communities in both regions. The consequences of these changes to birds and other wildlife in Minnesota are not well understood. Minnesota's forests harbor a greater diversity of songbirds than anywhere else in North America. Birds represent more than 70% of the more than 150 terrestrial vertebrate species in northern Minnesota forests. Development of forest management plans designed to sustain the diversity of these forests should address bird communities occupying them. To better understand the effects of forest management activities on bird communities in southern St. Louis County, bird census points were established in and around 24 sites which had been previously logged. Herpetofaunal sampling was also established on two of the 24 sites chosen for bird censuses. Results of these surveys were used to determine the use of recently harvested sites (and areas immediately surrounding them) by birds and herpetofauna and to establish baselines for continued monitoring of bird and herpetofaunal communities on these and additional sites. Objectives: The objectives of this initial year of surveying bird and herpetofaunal communities in regenerating habitats were to: (1) survey at least 20 recently-logged sites for breeding birds; (2) establish herpetofaunal sampling on two of these sites; and (3) establish a baseline for continued research on species associations in regenerating and other habitats in southern St. Louis County.
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    Conservation Assessment for Bay-breasted Warbler (Dendroica castanea)
    (University of Minnesota Duluth, 2003) Mayasich, Joseph M; Niemi, Gerald J
    This is a draft conservation assessment designed to provide a synopsis of the life history, ecology, and management and conservation concerns of the Bay-breasted Warbler (Dendroica castanea). The primary focus of this conservation assessment is on information relevant to Region 9 of the United States Department of Agriculture Forest Service. The Bay-breasted Warbler is a neotropical migrant that inhabits boreal coniferous forests in a broad band, primarily, across central and eastern Canada. It breeds in northern spruce-fir forests, feeding and nesting in the dense foliage of these conifers. It winters in Panama and northern South America. Males and females are fairly large relative to other members of the genus Dendroica, being 13 to 14 cm long and weighing about 13 g. Bay-breasted Warbler numbers have been reported to dramatically increase and decrease in synchrony with outbreaks and declines of the spruce budworm (Choristoneura fumiferana), a key food item. Its North American breeding distribution is closely correlated with that of spruce and fir in the boreal forest. The greatest threat to the breeding range of the Bay-breasted Warbler is the reduction in the area of old-growth spruce and fir of the boreal forest. Both nesting habitat and food supply (spruce budworm) are at risk when reductions or alterations of these forest areas occurs. Spraying insecticides to control spruce budworm can have direct toxic affect on this Warbler (inhibition of brain acetylcholinesterase activity). Winter habitat degradation and loss is also a threat, as commercial and residential development activity continues to reduce the forested habitats in the tropics. No specific or dedicated management activities have been attempted for the Bay-breasted Warbler in Region 9. If management activities are developed and implemented, they should address ecological sustainability. No past or current conservation activities in Region 9 are known to be relevant to the Bay-breasted Warbler. However, the adoption of an ecosystemcentered forest management perspective within Region 9 would likely help conserve inconspicuous boreal birds such as the Bay-breasted Warbler. No surveying, monitoring or research specific to the Bay-breasted Warbler has occurred or is occurring within the national forests of Region 9, although some generalized bird monitoring is occurring. Modifications to a point-count survey protocol could improve the monitoring of Bay-breasted Warblers in national forests. Considering the limited extent of its habitat within these forests, its migratory behavior and inconspicuous nature, declines in the abundance of Bay-breasted Warblers in Region 9 forests could easily be overlooked.
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    Monitoring Bird Populations on Biophysical Inventory Plots: St. Louis County, 1994
    (University of Minnesota Duluth, 1995) Montgomery, Kent; Niemi, Gerald J
    Neotropical migrant birds have recently received much attention following reported declines in many species that breed in eastern North America. Probable causes for such declines include events, such as habitat alteration, occurring on both breeding and wintering grounds. Changes in forest species composition and age structure, and the spatial arrangement of these forest components, may possibly influence bird communities in both regions. The consequences of these changes to birds and other wildlife in Minnesota are not well understood. Minnesota’s forests harbor a greater diversity of songbirds than anywhere else in North America. Birds represent more than 60% of the more than 150 vertebrate species in northern Minnesota forests. Development of forest management plans designed to sustain the diversity of these forests should address bird communities occupying them. To better understand the affect of forest management activities on bird communities in St. Louis County, a site-specific bird monitoring program was initiated on County Biophysical plots during June 1994. Census points were established on Biophysical plots and monitored for forest birds. Results of these censuses will be used to determine avian community composition within plots, refine species/habitat relationships for St. Louis County lands, establish baselines for continued monitoring of bird populations on selected plots, and explore landscape-level effects on avian communities.
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    Monitoring Bird Populations on Biophysical Inventory Plots: St. Louis County, 1994-1996
    (University of Minnesota Duluth, 1997) Montgomery, Kent; Niemi, Gerald J
    Neotropical migrant birds have recently received much attention following reported declines in many species that breed in eastern North America. Probable causes for such declines include events such as habitat alteration, occurring on both breeding and wintering grounds. Changes in forest species composition and age structure, and the spatial arrangement of these forest components may influence bird communities in both regions. The consequences of these changes to birds and other wildlife in Minnesota are not well understood. Minnesota's forests harbor a greater diversity of songbirds than anywhere else in North America. Birds represent more than 70% of the more than 150 terrestrial vertebrate species in northern Minnesota forests. Development of forest management plans designed to sustain the diversity of these forests should address bird communities occupying them. To better understand the affect of forest management activities on bird communities in St. Louis County, a site-specific bird monitoring program was initiated on biophysical plots. Bird census points were established on biophysical plots and surveyed for forest birds during June of 1994, 1995, and 1996. Results of these surveys were used to determine avian community composition within plots, refine species/habitat relationships for St. Louis County, and establish baselines for continued monitoring of bird populations on selected plots.
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    Monitoring Bird Populations on Biophysical Inventory Plots: St. Louis County, 1995
    (University of Minnesota Duluth, 1995) Montgomery, Kent; Niemi, Gerald J
    Neotropical migrant birds have recently received much attention following reported declines in many species that breed in eastern North America. Probable causes for such declines include events such as habitat alteration, occurring on both breeding and wintering grounds. Changes in forest species composition and age structure, and the spatial arrangement of these forest components may influence bird communities in both regions. The consequences of these changes to birds and other wildlife in Minnesota are not well understood. Minnesota's forests harbor a greater diversity of songbirds than anywhere else in North America. Birds represent more than 70% of the more than 150 terrestrial vertebrate species in northern Minnesota forests. Development of forest management plans designed to sustain the diversity of these forests should address bird communities occupying them. To better understand the affect of forest management activities on bird communities in St. Louis County, a site-specific bird monitoring program was initiated on biophysical plots. Bird census points were established on biophysical plots and surveyed for forest birds during June of 1994 and 1995. Results of these surveys were used to determine avian community composition within plots, refine species/habitat relationships for St. Louis County lands, identify changes in relative abundance of breeding birds between years, and establish baselines for continued monitoring of bird populations on selected plots.