Endotherms exhibit metabolic allometric slopes of 0.75, which were long viewed as evolutionary constraints but which are increasingly questioned. In insects, allometric relationships between body size and metabolism are understudied. We used comparative phylogenetic methods to investigate macroevolution of metabolic allometry in Odonata (dragonflies and damselflies), an insect group with a unique ecology and dramatic macroevol...

Climate warming is expected to influence the prevalence of vector‐transmitted parasites. Understanding the extent to which this is ongoing, or has already occurred, requires empirical data from populations monitored over long periods of time, but these studies are sparse. Further, vector‐disease research involving human health is often influenced by disease control efforts that supersede natural trends. By screening for malari...

The Svalbard Rock Ptarmigan, Lagopus muta hyperborea, is the only year-round resident terrestrial bird in the high Arctic. Many of the physiological and morphological adaptations permitting its winter endurance in this harsh environment are well understood. However, it remains unknown how the conspicuous moult from a greyish brown summer to a white winter plumage, and any underlying changes in plumage structure and feather mor...

Increasingly warmer springs have caused phenological shifts in both plants and animals. In birds, it is well established that mean laying date has advanced to match the earlier food peak. We know less about changes in the distribution of egg-laying dates within a population and the environmental variables that determine this variation. This could be an important component of how populations respond to climate change. We, there...

Many birds and mammals show substantial circadian variation in body temperature, which has been attributed to fluctuations in ambient temperature and energy reserves. However, to fully understand the variation in body temperature over the course of the day, we also need to consider effects of variation in work rate. We made use of a dataset on body temperature during the resting and active periods in female marsh tits ( Poecil...

Penguins face a major thermal transition when returning to land in a hypothermic state after a foraging trip. Uninsulated appendages (flippers and feet) could provide flexible heat exchange during subsequent rewarming. Here, we tested the hypothesis that peripheral vasodilation could be delayed during this recovery stage. To this end, we designed an experiment to examine patterns of surface rewarming in fully hypothermic (the...

Spending the winter in northern climes with short days and cold ambient temperatures ( T a ) can be energetically challenging for small birds that have high metabolic and heat loss rates. Hence, maintaining body temperature ( T b ) in T a below thermoneutrality can be energetically costly for a small bird. We still know little about how increased heat production below thermoneutrality affects the level at which T b is maintain...

The pied flycatcher is one of the most phenotypically variable bird species in Europe. The geographic variation in phenotypes has often been attributed to spatial variation in selection regimes that is associated with the presence or absence of the congeneric collared flycatcher. Spatial variation in phenotypes could however also be generated by spatially restricted gene flow and genetic drift. We examined the genetic populati...