Data for the paper "Reduced immune responsiveness contributes to energy conservation in an Arctic bird" by Nord, A., Hegemann, A., Folkow, L. P., J. Exp. Biol.

Data for the paper "Reduced immune responsiveness contributes to energy conservation in an Arctic bird" by Nord, A., Hegemann, A., Folkow, L. P., J. Exp. Biol.

Original data for: Nord, A., Nilsson, J.-Å. - Low incubation temperature retards the development of endothermy in a precocial bird

Original data for: Nord, A., Nilsson, J.-Å. - Low incubation temperature retards the development of endothermy in a precocial bird

Data from Nord & Folkow (2019): "Ambient temperature effects on stress-induced hyperthermia in Svalbard ptarmigan".

Data from Nord & Folkow (2019): "Ambient temperature effects on stress-induced hyperthermia in Svalbard ptarmigan".

Data from Nord, A & Cooper, C.B. Night conditions affect morning incubation behaviour differently across a latitudinal gradient. Ibis. https://doi.org/10.1111/ibi.12804

Data from Nord, A & Cooper, C.B. Night conditions affect morning incubation behaviour differently across a latitudinal gradient. Ibis. https://doi.org/10.1111/ibi.12804

The maximum work rate of animals has recently been suggested to be determined by the rate at which excess metabolic heat generated during work can be dissipated (heat dissipation limitation theory; HDL). As a first step towards testing this theory in wild animals, we experimentally manipulated brood size in breeding marsh tits (Poecile palustris) to change their work rate. Parents feeding nestlings generally operated at above-normal body temperatures. Body temperature in both males and females increased with maximum ambient temperature and with manipulated work rate, sometimes even exceeding 45 °C, which is close to suggested lethal levels for birds. Such high body temperatures have previously only been described for birds living in hot and arid regions. Thus, reproductive effort in marsh tits may potentially be limited by the rate of heat dissipation. Females had lower body temperatures, a possible consequence of their brood patch serving as a thermal window facilitating heat dissipation. Because increasing body temperatures are connected to somatic costs, we suggest that the HDL theory may constitute a possible mediator of the trade-off between current and future reproduction. It follows that globally increasing, more stochastic, ambient temperatures may restrict the capacity for sustained work of animals in the future.

Data on work rate, body temperature, surface temperature, body dimensions, and body mass change from breeding parents in an experiment where one group was heat-loss facilitated and one group was not. Data on nestling growth for nestlings sired by each group of parents, and subsidiary data on variation in ambient temperature at the study site.