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Full-Text Articles in Life Sciences
Geographic Segregation And Evidence Of Density-Dependent Changes In Sex Ratios In An Abundant Colonial Waterbird, Brian S. Dorr, Katie C. Hanson-Dorr, Travis L. Devault, Alban Guillaumet, Scott C. Barras
Geographic Segregation And Evidence Of Density-Dependent Changes In Sex Ratios In An Abundant Colonial Waterbird, Brian S. Dorr, Katie C. Hanson-Dorr, Travis L. Devault, Alban Guillaumet, Scott C. Barras
Brian S Dorr
Demographic information, such as geographic segregation of sexes and sex ratio data, is needed to develop, model and evaluate conservation and management strategies for wildlife. A variety of physiological, behavioral and environmental factors can influence segregation of sexes and sex ratios, many of which originate with density- dependent processes. Departure from 50:50 sex ratios of double-crested cormorants (Phalacrocorax auritus) collected during control efforts in breeding and wintering areas across their eastern range of the USA were evaluated using using a Z-test as well as Stouffer’s weighted Z-tests. In addition, a specifically-designed randomization test was used to evaluate density-dependent effects on …
Effects Of Prey Abundance On Breeding Season Diet Of Northern Goshawks (Accipiter Gentilis) Within An Unusual Prey Landscape, Robert A. Miller, Jay D. Carlisle, Marc J. Bechard
Effects Of Prey Abundance On Breeding Season Diet Of Northern Goshawks (Accipiter Gentilis) Within An Unusual Prey Landscape, Robert A. Miller, Jay D. Carlisle, Marc J. Bechard
Robert Miller
A critical element of diet analysis is species adaptability to alternative prey sources. The breeding season diet of Northern Goshawks (Accipiter gentilis) includes both mammalian and avian species, varies geographically, and is often dependent upon tree squirrels of the genera Sciurus and Tamiasciurus>/i>. We studied alternative prey sources of Northern Goshawks in the South Hills of south-central Idaho, an area where tree squirrels are naturally absent and other prey frequently important in the diet of goshawks, such as smaller corvids, are uncommon. We quantified the diet of goshawks using nest cameras and surveyed abundance of prey using line …
Avian Influenza Virus Prevalence In Migratory Waterfowl In The United States, 2007-2009, Scott R. Groepper Mr., Thomas Deliberto, Mark Vrtiska, Kerri Pedersen, Seth Swafford, Scott Hyngstrom
Avian Influenza Virus Prevalence In Migratory Waterfowl In The United States, 2007-2009, Scott R. Groepper Mr., Thomas Deliberto, Mark Vrtiska, Kerri Pedersen, Seth Swafford, Scott Hyngstrom
Scott R Groepper
SUMMARY. We analyzed 155,535 samples collected for surveillance of avian influenza viruses (AIVs), in the United States from 2007 to 2009, from migratory waterfowl (ducks, geese, and swans). The goal was to elucidate patterns of prevalence by flyway and functional groups to determine targets for future surveillance. Apparent prevalence of AIV was highest in the Pacific Flyway in 2007–2008 (14.2% and 14.1%, respectively), in the Mississippi Flyway in 2009 (16.8%), and lowest each year in the Atlantic Flyway (range, 7.3%–8.9%). Dabbling ducks had higher apparent prevalence of AIV (12.8%–18.8%) than diving ducks (3.9%–6.0%) or geese and swans (3.6%–3.9%). We observed …
Effects Of Disturbance And Climate Change On Ecosystem Performance In The Yukon River Basin Boreal Forest, Bruce K. Wylie, Matthew Rigge, Brian Brisco, Kevin Murnaghan, Jennifer A. Rover
Effects Of Disturbance And Climate Change On Ecosystem Performance In The Yukon River Basin Boreal Forest, Bruce K. Wylie, Matthew Rigge, Brian Brisco, Kevin Murnaghan, Jennifer A. Rover
Bruce K. Wylie
A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000–2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the …
Arbuscular Mycorrhizal Symbiosis And Ecosystem Processes: Prospects For Future Research In Tropical Soils, Geofrey Soka, Mark Ritchie
Arbuscular Mycorrhizal Symbiosis And Ecosystem Processes: Prospects For Future Research In Tropical Soils, Geofrey Soka, Mark Ritchie
Geofrey Soka
No abstract provided.