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Full-Text Articles in Physical Sciences and Mathematics
Herring Gulls, Larus Argentatus, Nesting On Sandusky Bay, Lake Erie, 1989, Richard A. Dolbeer, P.P. Woronecki, T. W. Seamans, B. N. Buckingham, E. C. Cleary
Herring Gulls, Larus Argentatus, Nesting On Sandusky Bay, Lake Erie, 1989, Richard A. Dolbeer, P.P. Woronecki, T. W. Seamans, B. N. Buckingham, E. C. Cleary
USDA Wildlife Services: Staff Publications
One of the largest herring gull (Larus argentatus} nesting populations on the Great Lakes is located in an urban setting on Sandusky Bay in the Ohio portion of Lake Erie. The survey reported here, carried out in 1989, indicated a population of 4,250 nests. The population has expanded from a focal point on Turning Point Island to coal piles at the Lower Lake Dock Company, rooftops in downtown Sandusky and breakwalls near Cedar Point. Comparison with data from a survey performed in 1976 indicates the population has grown at an average annual rate of 11.9% during the past 13 years. …
Biochemical And Morphological Characteristics In Maturing Achenes From Purple-Hulled And Oilseed Sunflower Cultivars, Roger W. Bullard, Paul P. Woronecki, Richard A. Dolbeer, J. Russell Mason
Biochemical And Morphological Characteristics In Maturing Achenes From Purple-Hulled And Oilseed Sunflower Cultivars, Roger W. Bullard, Paul P. Woronecki, Richard A. Dolbeer, J. Russell Mason
USDA Wildlife Services: Staff Publications
The blackbird feeding preference for sunflower oilseed variety Jacques Discovery (JD) over purple-hulled Neagra de Cluj (NdC) has been attributed to anthocyanin. To test this hypothesis, we compared biochemical and morphological properties in the achene over the maturation period. Comparisons included total phenols, anthocyanin, tannin, fat/oil, protein, nonstructural sugars, and phytomelanin contents, as well as mass properties and moisture content. Only three differences were observed: (1) Hull mass was significantly higher for NdC than JD. (2) Anthocyanins were synthesized by NdC only. (3) JD was higher in oil content. Each of these factors may play a role in reduced preferences …
The Use Of Banding Recovery Data To Estimate Dispersal Rates And Gene Flow In Avian Species: Case Studies In The Red-Winged Blackbird And Common Grackle , William S. Moore, Richard A. Dolbeer
The Use Of Banding Recovery Data To Estimate Dispersal Rates And Gene Flow In Avian Species: Case Studies In The Red-Winged Blackbird And Common Grackle , William S. Moore, Richard A. Dolbeer
USDA Wildlife Services: Staff Publications
Dispersal resulting in gene flow strongly affects the evolution of genetic structure in populations. This report describes statistical estimators of dispersal parameters based on USFWS banding recovery records. Finite-area studies of avian species yield estimates of root-mean-square (RMS) dispersal along a transect of about 1 km per generation. In contrast, estimates of RMS dispersal for the Red-winged Blackbird (Agelaiusp hoeniceus) and Common Grackle (Ouiscalus auiscula), based on USFWS banding recovery records, are 94.6 and 111.4 km per generation, respectively. Distributions for both species are extremely leptokurtic, and confidence intervals based on jackknife statistics are large because the estimators are sensitive …