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Full-Text Articles in Life Sciences
Predation Risk And Feeding Site Preferences In Winter Foraging Birds, Yen-Min Kuo
A foraging animal's choice of feeding location may represent a trade-off between maximizing its energy or nutrient intake and avoiding predation. In the present study, two hypotheses were investigated to test the influence of predation risk on feeding site preferences of birds: 1) there are differences among the preferences of feeding heights of birds, 2) the magnitude of preference increases with increasing predation risk found in different habitats. In my study site, three feeding stations (located in the woods, the woods/field edge, and an open field) each containing three feeders (0 m, 1.5 m, and 3 m ...
Effects Of Hypoxia On Egg Development In The Giant Waterbug (Belostoma Flumineum), Miki Furuya
I quantified the oxygen requirements of developing eggs and the adaptive significance of male brooding behavior in the giant waterbug (Belostoma flumineum). Egg pads brooded by males, and egg pads experimentally removed from the dorsa of males and maintained in a metabolic shaker, were tested for hatching success in four oxygen treatments (5%, 8%, 10% and 21%-control) in a closed laboratory system. All of the control male brooded egg pads, and 100% of the eggs/pad, hatched whereas none of the egg pads hatched in the 5% oxygen treatment. Fifteen of 20 (75%) male brooded egg pads in the ...
The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin
Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.
In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the ...