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Influence of Hardarian Gland Removal and Fur Lipid Removal on Heat-Loss and Water Flux to and from the Skin of Muskrats, Ondotra-Zibethicus, The
The Hardarian gland (an apocrine organ located behind the eye) was removed from one group of muskrats. Another group of muskrats was anesthetized and shampooed. The fur of shampooed and Hardarianectomized muskrats did not ...
Are Hummingbirds Facultatively Ammonotelic?: Nitrogen Excretion and Requirements as a Function of Body Size
Contributor:McWhorter, T. J.; Powers, D. R.; del Rio, Carlos Martinez
Most birds are uricotelic. An exception to this rule may be nectar-feeding birds, which excrete significant amounts of ammonia under certain conditions. Although ammonia is toxic, because it is highly water soluble its ...
Does Gut Function Limit Hummingbird Food Intake?
Contributor:McWhorter, T. J.; del Rio, Carlos Martinez
Many nectar-feeding bird species decrease food intake when sugar concentration in food is increased. This feeding response can be explained by two alternative hypotheses: compensatory feeding and physiological constraint. ...
Avoidance of Skeletal Muscle Atrophy in Spontaneous and Facultative Hibernators
Smooth and skeletal muscle changes were compared from overwintering white-tailed prairie dogs, spontaneous hibernators that undergo regular, low-temperature torpor bouts, and black-tailed prairie dogs, facultative hibernators ...
Respiratory Physiology of the Lake Magadi Tilapia (Oreochromis Alcalicus Grahami), a Fish Adapted to a Hot, Alkaline, and Frequently Hypoxic Environment
Contributor:Narahara, A.; Bergman, Harold; Laurent, P.; Maina, J. N.; Walsh, P. J.; Wood, C. M.
The tilapia Oreochromis alcalicus grahami is a unique ureotelic teleost, the only fish that lives in the alkaline hotsprings of Lake Magadi, Kenya. Physical conditions and fish behavior were monitored in the Fish Springs ...
Infection in the Classroom : Parasites as Models to Teach Biology
Contributor:Seville, R. Scott; Couch, L.; Seed, R.; Chappell, C.; Caira, J.; Patton, S.
Burrowing Owl (Athene Cunicularia) Population Genetics : A Comparison of North American Forms and Migratory Habits
Contributor:Korfanta, N. M.; McDonald, David; Glenn, T. C.
We assessed the effects of range disjunction, migratory habit, coloniality, and habitat structure on the genetic differentiation of North American Burrowing Owl (Athene cunicularia) populations. Burrowing Owls in North ...
Ion and Acid-Base Balance in Three Species of Amazonian Fish During Gradual Acidification of Extremely Soft Water
Contributor:Wilson, R. W.; Wood, C. M.; Gonzalez, R. J.; Patrick, M. L.; Bergman, Harold; Narahara, A.; Val, A. L.
Sensitivity to acid water was assessed in three species of Amazonian fish that encounter naturally acidic blackwaters to differing degrees in the wild: tambaqui (Colossoma macropomum), matrincha (Brycon erythropterum), and ...
Torpor and Other Physiological Adaptations of the Badger (Taxidea-Taxus) to Cold Environments
Oxygen consumption (Vo2) and heart rate were measured at ambient temperatures between +20 and -40 C. Basal metabolic rate was 0.3 cm3/g·h (65 beats/min), the body temperature was 38 C, the lower critical temperature (Tlc) ...
Membrane-Bound Intestinal Enzymes of Waxwings and Thrushes : Adaptive and Functional Implications of Patterns of Enzyme Activity, The
Contributor:Witmer, M. C.; del Rio, Carlos Martinez
Cedar waxwings (Bombycilla cedrorum) feed predominantly on fruits that are rich in simple sugars and low in nitrogen, supplementing this diet with arthropod prey during the summer months as well as flowers and tree sap in ...