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Articles 1 - 9 of 9

Full-Text Articles in Animal Sciences

Development Of Temperature Regulation In Nestling Tree Swallows, Richard Marsh Dec 2010

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 Dec 2010

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 …


Development Of Endothermy In Nestling Bank Swallows (Riparia Riparia), Richard L. Marsh Dec 2010

Development Of Endothermy In Nestling Bank Swallows (Riparia Riparia), Richard L. Marsh

Richard Marsh

Body temperature (Tb) measurements after exposure to air temperatures (Tₐ) of 20 C or 27 C for 2 h in conjunction with metabolism measurements were used to describe the timing of and basis for developing temperature regulation in nestling swallows. As growth proceeds from hatching to 10 g there is a gradual increase in the Tb after exposure to low Tₐ. As growth continues beyond this point, the ability of nestlings to maintain Tb above Tₐ improves rapidly, such that nestlings weighing over 14 g are completely homeothermic when exposed to 20 C. Conductance (C, in cal [g⋅h⋅°C]⁻¹) decreases throughout …


Effects On Nestling Age And Burrow Depth On Co₂ And O₂ Concentrations In The Burrows Of Bank Swallows (Riparia Riparia), Steven J. Wickler, Richard L. Marsh Dec 2010

Effects On Nestling Age And Burrow Depth On Co₂ And O₂ Concentrations In The Burrows Of Bank Swallows (Riparia Riparia), Steven J. Wickler, Richard L. Marsh

Richard Marsh

Gas samples were taken from the nest chambers of bank swallows (Riparia riparia) and analyzed for CO₂ and O₂ content. The mean CO₂ content was 2.62% with a maximum value of 5.58%, and the mean O₂ content was 17.83% with a minimum value of 14.61%. There was a positive and significant correlation of increasing CO₂ content with both increasing nestling age and increasing total metabolizing mass (adults plus young). With increasing metabolizing mass there is a linear increase in CO₂ content, which suggests no active regulation of gas concentrations. Burrow depth also affected CO₂, particularly in burrows with older nestlings. …


Seasonal And Geographic Variation Of Cold Resistance In House Finches Carpodacus Mexicanus, William Dawson, Richard Marsh, William Buttemer, Cynthia Carey Dec 2010

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 …


Winter Fattening In The American Goldfinch And The Possible Role Of Temperature In Its Regulation, William R. Dawson, Richard L. Marsh Dec 2010

Winter Fattening In The American Goldfinch And The Possible Role Of Temperature In Its Regulation, William R. Dawson, Richard L. Marsh

Richard Marsh

We investigated whether environmental temperature has any causal role in the winter fattening in certain finches of the subfamily Carduelinae. Correlational analyses between fat content of American goldfinches (Carduelis tristis) and various short- and long-term measures of temperature provide no evidence for a proximate role of this environmental variable in determining the degree of fattening of these birds in southeastern Michigan. Their fat content shows the best correlations (r = −.61 to −.63) with the long-term average minimum temperature or record low temperature for the date of capture. Furthermore, inclusion of long-term thermal measures in multivariate analyses excludes from significance …


Adaptations Of The Gray Catbird Dumetella Carolinensis To Long-Distance Migration: Flight Muscle Hypertrophy Associated With Elevated Body Mass, Richard L. Marsh Dec 2010

Adaptations Of The Gray Catbird Dumetella Carolinensis To Long-Distance Migration: Flight Muscle Hypertrophy Associated With Elevated Body Mass, Richard L. Marsh

Richard Marsh

The size and composition (lean-dry, water, and fat contents) of the flight muscles of the catbird were investigated as a function of the large seasonal changes in body mass which occur in this species. The mass of the pectoralis muscle is highly positively correlated with body mass, leading to an elevation in muscle mass of ∼35% during fall premigratory fattening. The changes in muscle mass are brought about by coordinated variations in all major components of the muscles which were measured. High-oxidative, fast-twitch fibers represent 88% of the total fibers in the pectoralis muscle. The cross-sectional area of the muscle …


The Enzymatic Basis Of High Metabolic Rates In Calling Frogs, Theodore L. Taigen, Kentwood D. Wells, Richard L. Marsh Dec 2010

The Enzymatic Basis Of High Metabolic Rates In Calling Frogs, Theodore L. Taigen, Kentwood D. Wells, Richard L. Marsh

Richard Marsh

Oxygen consumption by male spring peepers (Hyla crucifer) increased linearly with calling rate, reaching peak values of 1.5−1.7 ml O₂/(g⋅h) at the highest calling rates. The intercept of the regression line describing the relationship between metabolism and calling rate does not differ significantly from daytime resting metabolism (0.11 ml O₂/[g⋅h]). Metabolic rate during vigorous locomotor exercise at the same temperature (19 C) was only 1.1 ml O₂/(g⋅h). We measured activities of mitochondrial enzymes in the trunk muscles (internal and external obliques) involved in sound production and in mixed hind limb muscles of male and female frogs. Male trunk muscles were …


Measurement Of Maximum Oxygen Consumption In Guinea Fowl Numida Meleagris Indicates That Birds And Mammals Display A Similar Diversity Of Aerobic Scopes During Running, David J. Ellerby, Maryellen Cleary, Richard L. Marsh, Cindy I. Buchanan Dec 2010

Measurement Of Maximum Oxygen Consumption In Guinea Fowl Numida Meleagris Indicates That Birds And Mammals Display A Similar Diversity Of Aerobic Scopes During Running, David J. Ellerby, Maryellen Cleary, Richard L. Marsh, Cindy I. Buchanan

Richard Marsh

Judgement of exercise performance in birds has been hampered by a paucity of data on maximal aerobic capacity. We measured the maximal rate of oxygen consumption (V̇o₂,max) in running guinea fowl Numida meleagris, a bird that has been used in several previous studies of avian running. Mean V̇o₂,max during level treadmill running was 97.5±3.7 mL O&8322; kg⁻¹ min⁻¹ (mean ± SEM, N=5). V̇o₂,max was on average 6% higher when the birds ran uphill compared with the value during level running (paired t-test, P=0.041, N=5). The mean basal rate of oxygen consumption (V̇o₂,bmr) of the same individuals was 7.9±0.5 mL kg⁻¹ …