New information on how animals react to stress has been uncovered by a Roehampton research team.
Posted: 15 December 2014
King penguins from the research study
This was a fundamental piece of research that challenges our understanding of the ‘fight or flight’ reaction. The study revealed that the physiological reaction of an animal when exposed to a stressful situation is not necessarily an accurate measure of that animal’s stress.
Senior Lecturer Lewis Halsey, who worked on this research project alongside PhD alumnus Astrid Willener, tells us about their radical discoveries:
“This study questions the validity behind a deep-rooted belief that animals who are stressed respond with an increase in heart rate even if they don’t run away (in order to prepare them for fighting or fleeing)”.
Previously researchers have only investigated impacts of potential stresses on animals by measuring changes in their breathing and heart rate. Dr Willener says: “We were keen to look at the increase of movement in relation to the stress response of animals. Our recently published research sheds light on how stress factors affect the movement and activity levels of animals.”
The animals chosen for the study were king penguins, Dr Halsey tells us why:
“King penguins are a good model here because they don’t like to move off their egg even when stressed, although crucially we did still notice subtle but important increases in body movement when they were stressed. Our findings show that the typical way to measure stress using heart rate may not always be informative as the increase in heart rate may be more linked with the increase in movement than to their direct response to being under pressure.” says Dr Halsey.
Dr Willener reinforces the need to re-look at how stress is measured in animals: “These findings offer evidence that changing movement levels have an important effect on the stress response. The principal recommendation would be to double check the use of heart rate as a valid way of measuring stress, since it may not be accurate for all species or for all conditions. This is really important for animal welfare because if measuring stress inaccurately we may, for example, declare that an animal is not stressed when in reality they are, or vice-versa.”
The penguins used for the study were left to settle overnight and given a dummy egg to incubate. The methods used to stimulate stress were noises created from hitting metal together and random rapid movements relatively close to the animals. This lasted for a few minutes each time. The penguins were monitored after the experiments to ensure they re-accepted their own eggs and displayed fully natural behaviours back in the colony. The research findings enrich the learning of our Zoology
and Biological Sciences
students, by giving them exposure to the latest cutting-edge research to understand the behaviour of animals who are faced with situations of stress.
You can read full details about their research and key findings published
in the Journal Stress.