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Full-Text Articles in Life Sciences
Rocky Mountain Birds: Birds And Birding In The Central And Northern Rockies, Paul A. Johnsgard
Rocky Mountain Birds: Birds And Birding In The Central And Northern Rockies, Paul A. Johnsgard
Paul Johnsgard
“The Rocky Mountain region has fascinated me ever since I traveled to Glacier and Yellowstone National Parks as a teenager, and saw for the first time such wonderful birds as ospreys, American dippers, and Lewis’s woodpeckers.” This book is in part based on the author’s earlier Birds of the Rocky Mountains (1986, revised 2009), but over a third of the original text has been eliminated. The rest has been updated, expanded and modified to be less technical and more useful to birders in the field. Bird enthusiasts will find viewing locations and updated contact information for hundreds of sites in …
A Nebraska Bird-Finding Guide, Paul A. Johnsgard
A Nebraska Bird-Finding Guide, Paul A. Johnsgard
Paul Johnsgard
Nebraska lies in the transition zone between North American eastern and western avifaunas and is home to more than 200 breeding and 150 migrant species. This definitive guide to Nebraska birdwatching by the state’s preeminent ornithologist includes a county-by-county rundown of the best sites, a calendar of migrations, an annotated checklist of regularly occurring Nebraska birds, and recommendations for optical equipment, publications and reference materials, and contact information for conservation and ornithological groups. It features 48 maps as well as photographs and drawings by the author. Paul Johnsgard, Foundation Professor Emeritus of Biological Sciences at the University of Nebraska–Lincoln, is …
Development Of Endothermy In Nestling Bank Swallows (Riparia Riparia), Richard L. Marsh
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
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. …
Winter Fattening In The American Goldfinch And The Possible Role Of Temperature In Its Regulation, William R. Dawson, Richard L. Marsh
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
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 …
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
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 …
Homosexual Copulations By Male Tree Swallows, Michael P. Lombardo, Ruth M. Bosman, Christine A. Faro, Stephen G. Houtteman, Timothy S. Kluisza
Homosexual Copulations By Male Tree Swallows, Michael P. Lombardo, Ruth M. Bosman, Christine A. Faro, Stephen G. Houtteman, Timothy S. Kluisza
Michael P Lombardo
Homosexual courtship behavior in non-human animals is well known (Ford and Beach 1980) and occurs in a wide variety of taxa. However, homosexual copulations, especially between males, are less well known. In birds, males mounting other males have been observed in the colonially breeding Cattle Egret (Bubulcus ibis) (Fujioka and Yamagishi 1981) and Common Murre (Uria aalge) (Birkhead et al. 1985, Hatchwell 1988). Neither Fujioka and Yamagishi (1981) nor Birkhead et al. (1985) and Hatchwell (1988) reported whether cloacal contact occurred during their observations of male-male mountings. Here we describe homosexual copulations by male Tree Swallows …