The role of subordinates in vigilance inside family groups of Alpine marmots (Marmota marmota) and the structure of the pup’s screams

My master’s thesis is supervised by Prof. Klaus Zuberbühler and co-supervised by researchers from the Alpine Marmot Project , Dr. Aurélie Cohas and Dr. Thierry Lengagne, University of Lyon. I will study marmots (Marmota marmota) in La Grande Sassière nature reserve in the French Alps, where they have been studied for over twenty years.

The project will consist of an observational study on the vigilance behaviour of adult subordinates and in an analysis of pup’s screams. Indeed, marmots live in family groups composed of one dominant parental breeding pair, adult subordinates, yearlings (one-year old young individuals) and pups of the current year. Subordinates are sexually mature but do not breed in their natal group and they often interact with the juveniles and infants in different ways.

The aim of the observational study is to investigate how subordinate Alpine marmots contribute to helping infants and to which degree this species can be considered a cooperative breeder. If subordinates participate in successfully raising younger siblings, then they should help other group members by providing vigilance and alarm calling that goes beyond their individual interest. To address these questions, I will collect video-recorded data from different family groups of varying group composition, during periods of experimentally induced perturbation that will be perceived by individuals as high risk situations. My general hypothesis is that subordinates should increase their vigilance behaviour after infants are born and when they are in high risk situations.

For the second part of my project, I will record pup’s screams that are produced when they are caught by the researchers during the normal procedure of monitoring. In particular, I will investigate if there are individual signatures in these screams and also if there are differences depending on the body-mass of the individual (mass-size-frequency relationship) and what is the structure of these fairly unstudied screams. The hypotheses are that there should be individual differences in the composition of the screams and heavier pups should produce lower frequency screams, as it is the case for alarm calls. 

Future research linking the production of screams by pups to the subordinate’s behaviour will be able to use these recordings of the screams to perform play-back experiments to subordinates of the different families, in order to further investigate the function of subordinates in the protection of pups.