WOLF, B.O.: Using stable isotopes approaches to explore animal physiological ecology Stable isotope methods have been used in a number of situations to study resource use by animals and rely on the observation that the isotopic composition of an animal’s tissues reflects that of its diet. The stable isotope approach can also tell us about […]

KETTERSON, E.D.*; NOLAN, Jr., V.; CASTO, J.M.; NEUDORF, D.L.; GRINDSTAFF, J.L.; PARKER-RENGA, I.: Using Hormones to Explore Adaptation and Constraint in a Songbird We take an experimental approach to the evolution of life histories and the nature of adaptation and constraint. For the past 13 years, we have manipulated plasma levels of testosterone (T) in […]

HATCH, K.A.*; PINSHOW, B.; SPEAKMAN, J.R.: Stable sotopes in exhaled CO2 and the assessment of substrate metabolism in flying birds It is difficult to measure metabolic substrate use in flying birds. Indirect calorimetry can be used for short periods of time in wind tunnels but is not easily used in the field. Blood metabolite concentrations […]

HENEN, B.T.: Reproductive effort and reproductive nutrition of female desert tortoises: essential field methods The reproductive output of female desert tortoises (Gopherus agassizii) may appear independent of rainfall and the springtime abundance of their preferred food, annual plants. To evaluate whether body reserves (energy, water and other nutrients) influence reproductive success and its apparent independence […]

Piersma, T.*; van Gils, J.; Dekinga, A.; Spaans, B.; Dietz, M.W.; Visser, G.H.: Physiology-based trade-offs in diet and habitat selection of a small shorebird Red knots (Calidris canutus, Scolopacidae) are small, 120 g, shorebirds that breed on High Arctic tundra and spend the nonbreeding season in coastal intertidal areas, reaching much of the world’s coastlines […]

VLECK, C.*; VLECK, D.: Physiological condition and reproductive consequences in Adelie penguins Animals must make �decisions� (e.g. when or whether to breed, the effort to put into a breeding episode) by integrating physiological, environmental and social inputs. This integration can only be studied in a field context. Physiological measurements that provide reliable predictors of animals’ […]

FEDAK, M.*; LOVELL, P.; MCCONNELL, B.; HUNTER, C.: Methods for overcoming the constraints of long range telemetry of biological information from animals: getting more useful data from small packages Many species carry out their most interesting activities where they can not be observed or monitored. Marine mammals are perhaps extreme in this group, accomplishing their […]

Williams, J.B.*; Tieleman, B.I.: Evolutionary Physiology of larks Conventional wisdom holds that arid-zone birds occupy these climes because of the possession of physiological design features common to all members of the class Aves. Using broad scale comparisons, we tested the idea that desert birds have reduced energy expenditure and water loss compared to mesic counterparts. […]

WINGFIELD, J.C.*; SOMA, K.K.: Autumn and Spring Territoriality: Same Behavior, Different Mechanisms Vertebrates show a diverse array of social behaviors associated with territoriality. The mechanisms by which these behavioral patterns are regulated by hormones are diverse. Field and laboratory experiments indicate that general underlying themes – possibly mechanisms – do exist. For example, in birds, […]

GRASMAN, K.A.: Assessing Immunological Function in Toxicological Studies of Fish-Eating Birds Persistent organochlorine contaminants, especially polychlorinated biphenyls (PCBs) and 2,3,7,8-tetrachloro-p-dioxin (TCDD), have been shown to suppress immune function in rodents and chickens in the laboratory. Fish-eating birds are exposed to high levels of organochlorines in some ecosystems. Our objective was to assess the effects of […]