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Carbon And Nitrogen Isotopic Signatures Of Bat Guanos As A Record Of Past Environments, Hiroshi Mizutani, Donald A. Mcfarlane, Yuko Kabaya
Carbon And Nitrogen Isotopic Signatures Of Bat Guanos As A Record Of Past Environments, Hiroshi Mizutani, Donald A. Mcfarlane, Yuko Kabaya
WM Keck Science Faculty Papers
Carbon and nitrogen isotope ratios were measured for various ecogeochemical samples relevant to bat guano ecosystems. In particular, ca. 800-year-old subfossil guano from Jackson's Bay Cave Compex, Jamaica, yielded ratios similar to the modern guano from other Jamaican bat caves but quite different from modern guano of the same area. Diagenetic change and differences in bat food habits were unlikely explanations for the observation. Instead, insects that feed on C4 and CAM plants were the main prey for the bats in present Jackson's Bay area, while the ultimate source of organic matter for bats in other Jamaican caves and for …
Nitrogen And Carbon Isotope Studies Of A Bat Guano Core From Eagle Creek Cave, Arizona, Usa, Hiroshi Mizutani, Donald A. Mcfarlane, Yuko Kabaya
Nitrogen And Carbon Isotope Studies Of A Bat Guano Core From Eagle Creek Cave, Arizona, Usa, Hiroshi Mizutani, Donald A. Mcfarlane, Yuko Kabaya
WM Keck Science Faculty Papers
Nitrogen and carbon isotope ratios were studied in a stratified deposit of guano of Mexican Free-tailed bats in Eagle Creek Cave, Arizona, U.S.A. Little diagenetic change was observed over the 25-year time span of the guano deposit. High aridity and reduced circulation of air in the cave are hypothesized to have slowed the normally rapid decomposition of the excreta and the subsequent escape of resultant ammonia. The results suggest the high dependency of the speed of diagenetic change on specific physical and other conditions of the caves and indicate that great care need be exercised in the interpretation of the …
Effect Of Temperature And Humidity On Evaporative Water Loss In Anna's Hummingbird (Calypte Anna), Donald R. Powers
Effect Of Temperature And Humidity On Evaporative Water Loss In Anna's Hummingbird (Calypte Anna), Donald R. Powers
Faculty Publications - Department of Biological & Molecular Science
Evaporative water loss (EWL), oxygen concumption (V0 ), and body temperature (Tb) of Anna's 2 Hummingbirds (Calypte anna; ca. 4.5 g) were measured at combinations of ambient temperature (T J and water vapor density (Qva) ranging from 20 to 37 °C and 2 to 27 g · m-3 , respectively. The EWL decreased linearly with increasing eva at all temperatures. The slopes ofleast squares regression lines relating EWL to Qva at different temperatures were not significantly different and averaged -0.50mg H20·m-3 ·g-2 ·h-1 (range: -0.39 to -0.61). Increased Qva restricted EWL in C. anna more than has been reported for …