The climate matters
when measuring hormones from
faeces – be careful!
Measuring changes in hormones can tell us a lot about an animal’s welfare, health and reproductive condition, and non-invasive sampling (for example using faecal matter instead of blood) can limit the amount of stress caused to the animal being monitored. But faecal samples that are collected on an opportunistic basis might not be fresh or may have been exposed to the elements prior to collection. Does this matter?
Research by Yarnell & Walker (2017) suggests that temperature does indeed have an effect on the results obtained, with exposure to room temperature and high heat showing an increase in faecal glucocorticoid metabolite levels over time. This fundamental work shows the importance of considering sample collection and storage whilst designing experiments.