Terrestrial locomotion in the Svalbard ptarmigan (Lagopus muta hyperborea). How does treadmill running compare with running overground?

Abstract

The Svalbard rock ptarmigan (Lagopus muta hyperborea) is a resident bird on the Svalbard achipelago, living in an environment where it experiences extreme climatic and photoperiodic conditions. The bird’s most striking adaption to this environment is, prior to the onset of winter, its deposition of fat, comprising up to 30% of body mass. Moving around with this excess mass may prove difficult as it is likely to infer an extra energetic cost, especially at a time of food deprivation and low temperatures, where saving of energy is at prime concern. In order to study the impact of locomotion on the birds’ energy budget, treadmill studies have previously been carried out looking into both the bird’s energetics and biomechanical parameters. To validate these treadmill studies, I have conducted overground running studies to compare the running patterns of the two experimental environments. Do the birds display the same biomechanical patterns on the treadmill and in the natural environment? Additionally, blood gas and lactate analysis have been carried out while birds ran on the treadmill in order to assess their aerobic capacity, to validate the use of indirect calorimetry in the previous energetic studies.