In this Insight, Frédéric Angelier talks about his recent paper, Is telomere length a molecular marker of individual quality? Insights from a long‐lived bird, why looking at telomeres might be important for conservation efforts and what got him into ecology.
What’s the background to your paper?
Telomere length has been studied in biomedicine and short telomeres have been related to multiple ageing-related diseases in humans. In wild vertebrates, telomere length has similarly been related to longevity and there is often striking inter-individual variability in telomere length, irrespective of age. The origin and ultimate consequences of this variability in telomere length remain however unclear in wild vertebrates.
What’s your paper about?
Our paper’s aim was to understand whether inter-individual variability in telomere length could be related to individual quality (“the telomere length – individual quality hypothesis”). In wild vertebrates, some individuals consistently perform better than others and assessing individual quality has been a topic of interest for decades in ecology.
How did you come up with the idea for it?
While studying albatrosses during my PhD, I noticed that there was a huge inter-individual difference in performance (survival, breeding success) with some albatrosses living longer and producing way more offspring than others. Despite this variability in performance, it was impossible to tell these albatrosses apart. So, I wondered if physiological or molecular measurements could help scientists to identify these ‘super’ albatrosses.
How is your paper new or different from other work in this area?
So far, most papers have linked telomere length with individual survival while neglecting other potential proxies of individual quality. Here, we examined whether telomere length was not only linked to survival but also to offspring productivity, which was measured over a decade. In addition, we also tested whether telomere length could be related to other behavioural, physiological and morphological proxies of individual quality (foraging efficiency, stress hormone levels and body size). By using this robust and complementary approach, we were able to demonstrate that telomere length is related to performance and individual quality, at least in this species.
What does your work contribute to the field?
Previous studies have clearly shown that telomeres can be shortened by environmental stressors and demanding activities (e.g. reproduction). By demonstrating that telomere length can also be tightly connected to individual performance in this albatross species, this work adds a significant piece of evidence that telomere length can be useful to understand ecological processes, and more specifically, how environmental factors affect individuals and their ability to survive and reproduce in their environment.
Why is it important?
Assessing individual quality in wild vertebrates is particularly challenging because it requires following individuals over a major part of their life to record their survival and breeding performance. Our study suggests that measuring telomere length could be used by ecologists to assess individual quality and to study the influence of individual heterogeneity on ecological and demographic processes.
Does this article raise any new research questions?
Because telomere length is related to individual quality (body size, foraging efficiency and stress levels) and fitness (offspring productivity), our results suggest that telomere length could be useful to assess the conservation status of wild vertebrate populations. Because of environmental constraints, endangered populations could, for example, be mainly composed of individuals of poor individual quality. Under that scenario – and in a similar manner to the age structure of a population – the telomere structure of a population could be used to assess the conservation status of a population. This would be particularly exciting to test this hypothesis in multiple vertebrate populations (see Dupoué et al. 2017 Scientific Reports for an example).
About The Author
How did you get involved in ecology?
My first interest was in seabird natural history. As an undergraduate, I was lucky enough to do an initial internship in Svalbard (Arctic Norway) on the ecology of the Black-legged kittiwake and it was a revelation! I knew from that point that I wanted to study animal ecology and physiology, not only in seabirds but also in other vertebrates.
What are you currently working on?
I am especially interested in understanding how physiological mechanisms may constrain or enhance wild animals’ abilities to cope with ongoing environmental changes. My current work focuses on the way wild vertebrates may be impacted by urbanization, disturbance, climate change and pollution. I mainly study these questions in seabirds and common passerines.
What’s your current position?
I am a permanent researcher at the CNRS, Centre d’Etudes Biologiques de Chizé.
What project/article are you most proud of?
I am especially proud of my project regarding the impact of urbanization on wild passerine populations. I built this project from the beginning and it merges several subjects including ecology, behavioural science, physiology and ecotoxicology. In addition, it has involved several French and international students (PhD, post-doc), scientific collaborators, as well as local and regional managers and citizens. It has helped in identifying the benefits and costs of an urban way of life for common birds and it has provided practical suggestions to improve urban biodiversity.