Assessment of the amount of body water in the Red Knot (Calidris canutus): an evaluation of the principle of isotope dilution with 2H, (17)O, and (18)O as measured with laser spectrometry and isotope ratio mass spectrometry.

We have used the isotope dilution technique to study changes in the body composition of a migratory shorebird species (Red Knot, Calidris canutus) through an assessment of the amount of body water in it. Birds were quantitatively injected with a dose of water with elevated concentrations of 2H, (17)O, and (18)O. Thereafter, blood samples were taken and distilled.

The effects of temperature and artificial rain on the metabolism of American kestrels (Falco sparverius).

The effect of rainfall on the metabolism of birds is poorly understood. We measured the metabolism as rate of oxygen consumption (VO2) of four male and four female American kestrels (Falco sparverius) using open-circuit respirometry. We measured VO2 during the spring at ambient temperatures (Ta) of 5, 10, 15, and 25 degrees C in air without rainfall and with simulated rainfall of 2.

Avian food selection with application to pesticide risk assessment: are dead and desiccated insects a desirable food source?

Past evaluations of pesticide exposure have been conducted with substantial uncertainty regarding avian consumption of contaminated food items. One question is whether birds consume invertebrates that are killed by a chemical application and that may present an increasing chemical concentration as they desiccate. We addressed the research question in two phases.