Ecology of Small Insectivorous Birds in a Bottomland Hardwood Forest.

Changes in species composition and abundance, habitat use patterns and foraging behavior of 19 bird species in a bottomland hardwood forest in Louisiana were studied during the 1984-1989 breeding seasons. Species that used only one macrohabitat included the Yellow-throated Warbler along oxbow lake margins and the American Redstart, Swainson\u27s Warbler, and Hooded Warbler in non-flooded oak-gum-elm forest. The Northern Parula and Kentucky Warbler used 2 macrohabitats--non-flooded forest and oxbow lake margins. Thirteen species used 3 macrohabitats (non-flooded forest, seasonally flooded forest, and oxbow lake margins). I distinguished 6 groups of species that used similar microhabitat and foraging behavior. Ecological partitioning occurred primarily by (1) foraging height and height-related characters, (2) foraging locations within the forest canopy, and (3) differential use of foraging substrates and foraging maneuvers. Vegetation structure and height may be important in determining the abundance and combination of insectivorous birds existing at Tensas. Implications for management and conservation are discussed. To conserve migrant insectivorous birds, we must know the ranges, habitats, and patterns of habitat use. I selected a representative species, the Hooded Warbler, and compared habitat use and foraging ecology at a breeding and wintering site. Hooded Warbler winter distribution is concentrated along the Gulf of Mexico coast and Caribbean slope from southcentral Veracruz to Honduras. Winter habitat is typically undergrowth of humid forest; second-growth habitats are also important. At Tensas, hoodeds preferred dense foliage in the shrub and subcanopy layers, and captured prey primarily from the lower surfaces of leaves. At Los Tuxtlas, they were more generalized and captured prey from air and leaves, used a variety of other substrates, and foraged in open portions of the lower levels of the forest. Macro- and microhabitat use by Hooded Warblers were different at my study sites in the breeding and non-breeding ranges. I believe, the use of habitats varies between locations such as the wintering and breeding grounds for many species; to evaluate the relative importance of any proposed habitat changes, we must know how the changes will affect macro- and microhabitat and how the species use macro- and microhabitat

Linking Animals Aloft with the Terrestrial Landscape

Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals

Linking Animals Aloft with the Terrestrial Landscape

Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals

Nonlinear Dynamics in Ecosystem Response to Climatic Change: Case Studies and Policy Implications

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear

The epidemiology of coronary heart disease : A review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31999/1/0000041.pd

Science and the Storms: the USGS Response to the Hurricanes of 2005 - Chapter Six: Ecological Impacts

Ecological impacts from the hurricanes of 2005 affected both vegetation and the animals that depend on coastal habits on land and in water. Discussed in this section are migratory birds, coastal marsh vegetation, chenier forests, coastal floodplain forests, mangrove forests, estuaries, and the endangered manatee

Linking Animals Aloft with the Terrestrial Landscape

Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals