Subject: Testing the effects of physiological stress on cognition and its links with fitness in the wild: empirical approaches
PhD Supervisor: Doligez Blandine (LBBE, UMR 5558, Université de Lyon 1) and Bize Pierre (School of Biological Sciences, University of Aberdeen)
Description:
How animals gather, process and use information (i.e. cognitive abilities) is at the heart of behavioural flexibility, which has been proposed as a particularly powerful way for individuals to cope with spatio-temporal variation of the environment. Adjusting behavioural decisions to solve unexpected problems imposed by environmental changes may for instance require the ability to use novel behaviour patterns (i.e. innovation) and/or modify behaviours according to acquired information (i.e. learning). While these cognitive abilities are found in many taxa, we currently know very little about the variation of these abilities among and within individuals, and more specifically the mechanisms underlying this variation and its link with fitness components. This information is nonetheless essential to understand how cognitive abilities in the wild shape the rapid adaptation of populations to past, but also current, human-induced, environmental changes.
Variation
in cognitive abilities and their fitness consequences have been
suggested to be indirectly linked to individual condition and
more particularly
physiological (including oxidative) stress. Accordingly, an
increase in oxidative stress, as observed in ageing individuals,
has been shown to lead to a decrease in cognitive functions
in humans and laboratory animals. Furthermore,
oxidative stress has also been found to shape reproductive success in
wild populations. Thus, variation in oxidative stress may
simultaneously affect cognitive abilities and fitness components,
creating an indirect link between them. The aim of
the PhD is to explore this hypothesis and unravel causal mechanisms
linking variation in cognitive abilities and variation in fitness
components using correlative and experimental approaches in a
study population of great tits Parus major
on Gotland, Sweden. In this population, cognitive tests have
now been successfully implemented during breeding; cognitive and
reproductive data have been collected, and the level of oxidative stress
can be experimentally manipulated. The PhD
project includes two main research axes, which will provide the
first in-depth investigation of physiological (stress) mechanisms
underlying the links between cognitive abilities and fitness.
Objective 1: Testing the link between adult oxidative
stress and variation in cognitive abilities and its link with
reproductive success, especially with age. In the study
population, we have found an age-related decline
in cognitive abilities. Based on blood samples collected in
breeding adults whose cognitive abilities have been measured, the PhD
student will first correlatively investigate whether this age-related
decline is linked to an increase in several markers
of oxidative stress (as well as hormonal stress). In a second step, an
experimental supplementation of dietary antioxidants will be used
in adults of different age categories to test the causality of
the links between oxidative stress
and variation in cognitive abilities and fitness components.
Objective 2: Testing the long-term influence of developmental
conditions, and in particular oxidative stress, on adult cognitive
abilities.Based on the long-term monitoring of the study population,
the PhD student will first correlatively explore
whether the growing conditions during nestling development
affect cognitive abilities in the long-term, in adulthood. In a
second step, an experimental supplementation of dietary antioxidants
will again be used, this time on nestlings, to manipulate
the level of oxidative stress during development and test the
long-term consequences on variation in cognitive abilities and fitness
components after recruitment.
The
PhD project will rely on national (S. Massemin and F. Criscuolo, IPHC,
University of Strasbourg) and international (co-direction with P.
Bize and
L. Cauchard, Aberdeen University, UK) collaborations. The
feasibility of the proposed work is guaranteed by the presence
of data and samples already collected and field protocols
successfully used for several years in the study population,
as well as funding secured for the field work and lab analyses via an
ANR grant (Evol-cog, 2020-2024).
Required skills: The candidate must hold a Research Master
(Master 2 Recherche) in the fields of evolutionary and/or
behavioural ecology and/or ecophysiology, have excellent skills in
statistics and data analyses (preferentially using R),
and have strong interest for (and if possible previous
experience with) both field work and lab work.
To apply, please send a detailed CV and a letter of motivation to blandine.doligez@univ-lyon1.fr and pierre.bize@abdn.ac.uk as soon as possible (we need to choose a candidate before june 14)
Dr. Laure Cauchard
School of Biological Sciences
University of Aberdeen