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Full-Text Articles in Animal Sciences
Development Of Temperature Regulation In Nestling Tree Swallows, Richard Marsh
Development Of Temperature Regulation In Nestling Tree Swallows, Richard Marsh
Richard Marsh
No abstract provided.
Adaptations Of The Gray Catbird Dumetella Carolinensis To Long Distance Migration: Energy Stores And Substrate Concentrations In Plasma, Richard Marsh
Adaptations Of The Gray Catbird Dumetella Carolinensis To Long Distance Migration: Energy Stores And Substrate Concentrations In Plasma, Richard Marsh
Richard Marsh
The major body components (water, lean dry, and fat) were measured in the carcasses of Gray Catbirds from which the flight muscles had been removed. Birds were collected from May through October near Ann Arbor, Michigan and during September and October near Gainesville, Florida. Additionally, the glycogen content of muscle and liver and the concentrations of glucose and triglycerides in plasma were determined in catbirds sampled during fall migration in Florida. Catbirds attained maximum body masses of ∼50 g in Florida, largely due to the addition of fat. Relatively lean birds (∼3-4% body fat) in spring through fall weighed approximately …
Seasonal And Geographic Variation Of Cold Resistance In House Finches Carpodacus Mexicanus, William Dawson, Richard Marsh, William Buttemer, Cynthia Carey
Seasonal And Geographic Variation Of Cold Resistance In House Finches Carpodacus Mexicanus, William Dawson, Richard Marsh, William Buttemer, Cynthia Carey
Richard Marsh
The house finch (Carpodacus mexicanus) is resident in tropical and subtropical regions as well as in localities having relatively severe winters. The extent of its winter acclimatization was assessed in freshly captured individuals of this species from southern California and Colorado. In severe cold stress tests involving exposure to Tₐ < −60 C, the former did not remain homeothermic any longer in winter than in late spring, whereas the Colorado birds did (8.8 vs. 97.5 min; P < .001). The capacity for winter acclimatization evident in these Colorado individuals was correlated with modest winter fattening, a response lacking in those from southern …