• Research
  • Education

From Bordeaux to the Galápagos: the journey of an inspired student

Updated on:

Zoé Bescond--Michel's career path reflects the curiosity and determination of a generation of students committed to ecology. Educated at the University of Bordeaux, she has already published an article in Nature Communications and is now pursuing a PhD focussed on introduced species.

Photo : Zoe Bescond-Michel presented her PhD project at the 7th Galápagos Symposium last July © Galápagos Science Centre
Zoe Bescond-Michel presented her PhD project at the 7th Galápagos Symposium last July © Galápagos Science Centre

What do bullfrogs, nutria, Asian hornets and tiger mosquitoes have in common? Apart from being among the most unpopular animals with the general public, these four species were introduced to France as a result of human activity. While nutria was voluntarily introduced at the end of the 19th century for its fur, Asian hornets and tiger mosquitoes arrived in Europe, a priori, via containers from Asia in the early 2000s. Another common feature is that these species are considered invasive because of the disruption they cause to ecosystems and human health. Can species be introduced without having a negative impact on their ecosystems? This is one of the ecological questions that has interested Zoé Bescond--Michel since her studies at the University of Bordeaux, particularly during her Master degree in Biodiversity, Ecology and Evolution. Recently, she published the results of her Master internship at the University of Fribourg (Switzerland) in the journal Nature Communications. In her study, she focused on the introduction of large mammals such as deer, cattle, horses and elephants. The internship, which was too short to allow for fieldwork, resulted in a so-called meta-analysis, conducted between January and June 2023, supervised by ecology researchers Sven Bacher and Giovanni Vimercati, who are co-authors of the paper. In other words, the young researcher collected and compared data from more than 200 scientific articles published since 1950 on 66 species of ungulates. "If, for example, an introduced deer starts eating plant A, which was competing with plant B, then plant B can benefit from the presence of the ungulate and thrive," she explains.

The study was conducted using an international assessment system developed by the International Union for Conservation of Nature (IUCN) for both negative (EICAT*) and positive (EICAT+) impacts. Five levels of impact can be attributed to a species. These levels range from a negligible effect or benefit to the irreversible disappearance of a species, on the negative side, or, conversely, establish that extinction has been definitively avoided, on the positive side.

A scientific paper, a symphony composed by many hands

Zoé Bescond--Michel has focused more closely on 300 positive impacts. "There is a debate about introduced species in particular, and the positive aspects are sometimes overlooked. To make the best conservation decisions, you have to look at the whole picture," says the student, who grew up in Ambès, in the Bordeaux metropolitan area.

The study ultimately concluded that the negative impacts of introducing herbivores are more frequent and of greater magnitude than the positive impacts. It also shows that island species, which have not evolved alongside ungulates, are particularly vulnerable, as are species higher up the food chain. For example, when ungulates trample grasses and destroy vegetation, there are fewer insectivorous birds and therefore less prey for birds of prey, leading to a decline in raptor populations. "The publication is based on my internship report, but the text has evolved considerably over time. Sven and Giovanni used it as a starting point and improved it," explains the young researcher.

Fisheye photograph, normally used to capture the canopy above vegetation plots. © Zoé Bescond--Michel
Fisheye photograph, normally used to capture the canopy above vegetation plots. © Zoé Bescond--Michel

Virgil Fievet, head of the Master 2 research programme in "Biodiversity and functioning of terrestrial ecosystems", followed by Zoé Bescond--Michel, points out that writing a publication is a "symphony of many hands that follows a specific code", which is learned during the Master programme. He emphasises the skills and confidence placed in the student by Swiss researchers for submission to a journal of the calibre of Nature Communications. "It was a risky gamble: a rejection would have meant reconfiguring everything for another journal." For the lecturer-researcher at the Biodiversity, Genes and Communities Laboratory (BIOGECO2), publishing during a Master degree is fairly common, with two or three articles per year from a cohort of 15 students. Publishing as first author, which is the most operational position in this type of publication, in a journal of the Nature group is more exceptional and, for him, bodes well for Zoé Bescond--Michel's past and future career. "I am pleasantly surprised by the shift towards an increasingly strong commitment to the environment and ecology among all Master students in recent years."

A passion that grows with each internship

Initially, the young woman from Bordeaux thought she would become a veterinarian. "But in the end, I wanted to study wild animals more than I wanted to treat sick animals in the city." After completing her secondary education at the Gustave Eiffel High School in Bordeaux, she enrolled at university to study for a Bachelor degree in life sciences, with the dream of completing a PhD, even though she didn’t know all the ins and outs of the degree. The student went on to carry out a series of internships: in Toulouse on the behaviour of ants, in Vienne at a primate conservation centre, which ultimately convinced her that the study of animal behaviour, ethology, might not be for her. "I found it a bit tedious to spend all day observing." She also spent a few weeks with the Zebrafish association and Patrick Babin's team at the Rare Diseases: Genetics and Metabolism Laboratory (MRGM3) for a scientific mediation internship. There, she discovered a desire to share research with as many people as possible. Hesitant, she opted for a professional Master degree for a while, before the programme director, Alexia Legeay, redirected her towards a research specialisation in view of her background and initial aspirations.

 

I definitely made the right choice to choose the University of Bordeaux after secondary school. I really thrived there and found a subject that truly interested me.

With her third year of undergraduate studies in Ottawa, Canada, cancelled due to Covid, Zoé applied for her first year of Master studies in Linköping, Sweden's fifth largest city. There, her interest in ecology was further sharpened through a research internship on invasive species in the Baltic Sea. "What happens when a new species – a crab, an algae – is added to the ecosystem?" She had just discovered her favourite subject! After simply searching for "introduced species" in an academic search engine, she came across the work of Giovanni Vimercati, then a postdoctoral researcher in the team of applied ecology professor Sven Bacher in the biology department at the University of Fribourg. Two emails and a few hours later, she was embarking on a six-month internship with "great freedom in terms of research topics".

New ecosystem, new field of research

Zoé often mentions luck when talking about her career path. But what stands out above all is her strong determination. The same determination that enabled her to overcome her apprehensions about statistics during her various internships and about the English language. "I forced myself to stay in an international group during my first days in Sweden and not with the French students. It was hard, but after two weeks, I realised I didn't need to translate anymore." The same determination led her, after her Master degree, to take a break with her backpack in New Zealand, Fiji and Indonesia. But not before working in Bordeaux to finance her trip, notably at a famous ice cream parlour on Place Saint-Pierre (her favourites: lemon-basil, raspberry and hibiscus!). "I still can't believe how much I learned there" between hiking, diving, stays in the jungle... with the same interest in conservation issues.

Today, she says she does not yet realise the significance of this publication in Nature Communications, but has resumed her collaboration with Sven Bacher's team, this time for a thesis. The subject is the same, but there are more species and, above all, a new ecosystem: the Galápagos Islands, off the coast of Ecuador in the South Pacific. She will study – again as part of a meta-analysis – five groups of introduced species: ungulates, rodents, ants and two plants (rosaceae and verbenaceae). In addition, she will conduct fieldwork in the Galápagos with two species: Lantana camara (a plant of the verbenaceae family) and Solenopsis geminata (an ant).

Will the impacts collected in the meta-analyses of these two species make it possible to predict impacts at the local level? This will be one of the challenges of her research. She has just returned from her first three-month stay – the first of four planned. "It's intense, but it's great!" she explains with a smile, discovering how to work independently with a student, Paola Tatiana Flores Males, and a research assistant, Manuel Mejía-Toro from the University of San Francisco in Quito and the Galapagos Science Centre (photo opposite), to choose the sites for collecting the ants and verbenaceae to be studied next year.

In the Galápagos, Zoé Bescond--Michel discovered Ecuadorian culture and a new ideal playground for her passion for analogue photography, surrounded by birds, tortoises and sea lions. She concludes: "I clearly made the right choice in going to the University of Bordeaux after secondary school. I thrived there and found the subject that truly interests me."

1EICAT: Environmental Impact Classification for Alien Taxa
2INRAE unit and University of Bordeaux
3Inserm unit and University of Bordeaux

 

Paola Tatiana Flores Males and Manuel Mejía-Toro, who are supporting the French student in her fieldwork. © Zoé Bescond--Michel (analogue photograph)
Paola Tatiana Flores Males and Manuel Mejía-Toro, who are supporting the French student in her fieldwork. © Zoé Bescond--Michel (analogue photograph)

References

Harms of introduced large herbivores outweigh benefits to native biodiversity

Zoé Bescond--Michel, Sven Bacher & Giovanni Vimercati

Nature Communications volume 16, Article number : 8260 (2025)

Find out more

Contacts

  • Zoé Bescond--Michel

    zoe.bescond--michel%40unifr.ch

  • Delphine Charles

    Science communication officer

    delphine.charles%40u-bordeaux.fr