Archive for April, 2014


When I was young – yes, that was indeed last century – I made a paper with two American scientists that I had never met. I one them I met years after, on the other side of the world (for me), in New Zealand. The guy is quite fascinating for a number of reasons, one of which being that he has wild ideas, the type that divides the world into those that will call him a genius and those that will loath him, ever after. That’s Josh Donlan. A few years back, he published a paper in Nature that created some waves in the normally well-behaving community of conservation biologists, about assisted colonization: rewilding North America.

The idea is that the Pleistocene is not so far away, in eco-evolutionary times, and that a few thousands years ago, the great mammalian megafauna was still roaming the plains where Clint Eastwood rode yesterday. So in terms of ecology, there are a bunch of key ecological processes that are not performed by these beasts anymore. Also, there exist large animals in the world now that could somehow replace their extinct ancestors: elephants, camels, lions, horses, giant tortoises… Wait, it gets even better: many of these species are currently endangered in their native areas, so translocating them into North America could also alleviate some of the threats they face in Africa and Asia, such as poaching. Just think about some critically endangered Equidae, like the Przewalski’s horse. Or like the wild Asian ass. I’d put you an image of this magnificent animal, but I seem to have problem with my browser; it behaves strangely.

Brilliant idea, but… There are a number of problems as well. Let’s put aside the fact that it is very costly, long and probably logistically nightmarish to obtain a large population of a large mammal from another continent. Remains two drawbacks as big as that mega-fauna. First, there are important conflicts with humans and some of these animals, in particular elephants and lions. Human-animal conflicts are so problematic that entire sessions are devoted to them in conservation meetings. Second, putting species where they don’t belong ecologically often leads to biological invasions, something that can be very nasty. Ask the Australians about the half-million feral horses and twice that many camels that roam in their backyard.

So on one hand, we have a superb solution to save some endangered species with a really bleak future, and in the meantime restore the ecological functioning of the great plains of late (while providing some amazing sights that will undoubtedly increase the ecotourism value of the Giant Sequoia National Park); and on the other one, we have a potentially evil danger of novel human-animal conflicts doubled with uncontrollable alien invasive species. A perfect debate menu for our Semibière meetings (see the previous post on that).

So, what about you, my friend. You’d be against, or for it?



Yes, I mentioned that earlier: we study invasive ants. We do all kind of fun things we them, from models trying to predict where they could be invasive, now or with climate change, to lab experiment trying to see which species are better at finding and monopolising resources. There are a bunch of papers now that we have published on that (and more to come, that I will probably advertise here, so I won’t say too much now), but the point is, they are very interesting, and quite problematic for biodiversity and economics alike.

There are about 20 000 ants species out there (40% of which remaining to be described by science). One percent of these species are exotic, meaning they have been introduced outside their native range, and seem to have been established there. About a tenth of these 200 exotic species are known to be highly invasive. That mean they are mean. And I do mean mean. Not the mean mean, really mean. Ok, I stop. They are highly aggressive and exceedingly efficient. When they invade, they destroy the native entomofauna, starting by the native ant communities, but also affecting plants, other invertebrates, amphibians, reptiles, birds and even mammals. Humans are known to be victims of the Red Imported Fire Ant by the thousands in the USA (with hundreds of death – that is more than by sharks). They really affect biodiversity and doing so they disrupt ecosystem functioning and services (like pollination and seed dispersal). And they cause billions of dollars of damage every year to agriculture, forestry, real estate and public health.

Oh, and they also go by scary names, like the fire ant, the electric ant, the crazy ant, the destroyer ant, the ghost ant… And before you ask, yes there are zombie ants and vampire ants as well, only they are not invasive ants. No werewolf ant though. Kinda disappointing.

Anyway, invasive ants are about to take over the planet, and who is working their ass off trying to save the day, in the general ingratitude? To whom will you turn when they try and make you their slave? Biodiversity Dynamics, thank you.

So, to answer the question in the title, we study invasive ants, simply because invasive ants are importants. Import-ants. Get it? Ok ok, I thought that was a good one…



Ever wondered why ant colonies are so big? One talks about millions of individuals in some colonies. And for people working on invasive ants, like us, this thought can be both fascinating and frightening (BTW, we work on invasive ants, because they are importants. Sorry.). Take the Argentine ant for example. It forms “supercolonies” (related colonies) that can encompass tens of thousands of nests over thousands of kilometres. This amounts to perhaps hundreds of millions of tiny, mean brothers-in-arms that will attack and effectively kill almost anything they encounter and that is small and stupid enough to hang around. Sweet little things. We love them. Later on, I’ll tell you how we compare the nastiness of the various invasive ant species, and believe me, Mother Nature had loads of fun – and bursts of creativity – when She created ants.

But for now, how did they manage to evolve such immense social colonies? One answer could come from our study of Allee effects. An Allee effect is a positive relationship between the size of a population and its capacity to persist and grow. In a word, in some species, the more individuals there are, they better they do, often because they help each other in some various ways. So, we studied Allee effects in ants; just because we study all we can about the Allee effect (because we are a bit monomaniac) and because we like ants. We like rhinos too, but that’s less practical in a lab. Oh, and of course because, very surprisingly, nobody ever had the idea (or the madness?) to look into that.

So, we set up large experimental designs to record the survival and reproduction of colonies of various sizes. By various sizes, I mean different number of workers and different numbers of queens. Because, yes, some ant species live with several (sometimes hundreds of) queens in the same nest. And after a few years of hard work, the results were worth it: there are indeed Allee effects in ants; at least the two species we studied. The corresponding paper is here. The more ants, the better they do. And it even gets better: the more queens, the more workers are produced per queen (that’s not that obvious, they could compete for food). And also, the more queens, the better the workers survive (don’t ask me why, I’m supposed to be concise here). And the fun continues: the more workers, the higher the queens productivity! So in fact, each cast (workers and queens) benefit the other cast, so that it creates a mad feedback loop leading to ever growing colonies (that I think can possibly only end in them taking over the world). So this mechanism of Allee effect might have played an important role into making large colonies of eusocial species. Nice no? Oh, come on!



What, no funny image? Yes, this one IS funny too, just watch closer!

Bonjour les petits lapins!

Now that you are totally convinced that your supervisor is more going to influence your PhD success than the subject would, you are wondering how to identify a good supervisor. If I tell you “that’s the one that proposes good PhD subjects”, you’re going to throw me carrots, so I’d better develop a bit. I said “a bit”, but that’s a figure of speech. Difficult to develop it in just one paragraph and one cartoon.

It may seem ridiculously obvious, but I think a good research supervisor primarily needs to be a good researcher. First because I don’t believe it is possible to show well the ropes of any profession if you don’t master them yourself; second because it may be even harder to transmit the compulsory need for passion for doing research if you’re not good at it. And also, I am a strong believer that you learn much by seeing what you like and dislike in the way your supervisor does research even if it is not an explicit lesson. I believe in “leading by the example” even if I can resort to “do what I say, not what I do” when I mess up. So your supervisor should be someone you want to take example on. Better choose a good scientist then. Perhaps I’ll post one day on what I think this means. I don’t have enough enemies yet.

Should you choose a man or a woman? If you’re more confortable with either sex (but that’d be odd), then chose it. Otherwise, it’s an irrelevant question. Should you find a young scientist or an old one? Well, a young one is less experimented but probably has a smaller lab so more time and perhaps more enthusiasm, so there’s a balance here that means both can be good. One thing that is for sure is that he/she needs to like supervising, and to devote to you a significant amount of his/her time. That doesn’t mean just above 0.05, even if a precise percentage would be meaningless here. People have different ways of supervising, some leave more autonomy and are available upon request, some sit with the students in front of their computer to show them how to do stuff. Some spend a lot of time discussing ideas, or interpreting results. Regardless of the specific way, the importance is availability.

Your supervisor should not impose one immovable PhD subject but should instead build with you an excellent project that is tailored to you, that you will enjoy doing. That does not mean letting you work on dolphins or chimps because you’ve always loved them, but to show you what the lab does, understand what you seem to be most interested in and adapt the most topical subjects so that the subject will be gradually adapted to fit you while still being relevant to the lab and the most sexy, head-smashing brilliant subject ever. That subject will evolve with time during the three years of your PhD. Because science changes, because you will change, and because your first results will probably shift your initial priorities and interests. Your supervisor should encourage you to become gradually independent and to shape you thesis with his/her guidance. The subject has to become your baby, the one you work for, you wake up for, you fight for and are ready to die for. Ok, maybe I’m getting a bit ahead of myself but you get the idea.

Over the course of your PhD, your supervisor must be prepared/able to show you, directly or indirectly, how to write research papers and grants, how to review papers for journals, how to prepare posters and talks, how to communicate to the public and how to prepare the next steps of your career. The two of you will form a team, so that’s one that has to be strong, to work on trust, and to aim for pride and success of the team mate. And it goes both ways.


Still there? Ok, you’re half way through the post, bear with me. So, how to you know who has at least some of these requisites? There are several ways. First, remember that the PhD interview goes both ways. It is also a way for you to assess whether the prof would suit you, seems to think the way you expect about a supervision, and if the lab more generally would suit you. I often say that students should be able to ask profs for recommendation letters from former students/postdocs, which they obviously can’t, but that’s a pity. Still, they can contact former students and lab members, ask around when they visit the lab and generally try to get info from students and staff alike, either upfront or more subtly according to the circumstance. Ask about the style of the supervision (not the quality, subtlety I said). Your supervisor should be proud of your work, let you present your data in meetings and mention your contribution when he/she presents it. Obviously, he/she should not put two or more students in competition over the same subject (and not have too many students anyway), write papers in your place, take ages to read and edit your drafts, fail to be encouraging or supporting of your limitations, deny you opportunities to take courses or to visit other labs to learn new methods/techniques. Your supervisor should not expect a given number of hours or day in the lab. If too much emphasis on this, then this is suspect. If your project is your baby, you’re not going to count the hours yourself, so why should someone else? Also, when you visit the lab (which should be proposed), try to assess the ambiance, if the students seem generally happy to be there (don’t confuse stress with discontentment). Finally, look also at the scientific output of former students, the number and quality of the papers they produce, as it’s likely to be indicative of your own once you’re there.

The perfect supervisor doesn’t exist, don’t look for that. But there are tons of very good ones over there, and I’ve given you some keys to find them. But most importantly I think, I’ve told you that it’s more important to make your choice over the supervisor than over the topic. Ah, and one last thing that I think is essential. You should like your supervisor, or at least not dislike him/her upfront. Whether or not to bond with students/supervisor is a very interesting topic per se – one that I’ll treat later – but just… no, I said later.

Now, I’m of course not trying to imply that I’m all that. Supervising is not easy and even if you know what you’re supposed to do on paper, managing to do it on a daily basis is not that obvious. Plus, a supervision is a two-ways relationship and it cannot work well if the student is not fully in the game. And believe me, finding a good PhD student is at least as hard to find as a good PhD supervisor. Ah! Just to end up on a nice note: I’ve been very lucky with all my PhD students so far, and totally blessed with the last two.

So, obviously, next post: how to fool your potential supervisor into believing that you would be a good PhD student. Or my own personal expectations during student interviews.

One very important aspect of a good lab it its internal scientific activity. Students and staff benefit much from a dynamic scientific environment. Regular meetings where science is presented and discussed is something that will develop your communications skills, your ability to synthesize, to get a critical view of approaches and topics and simply will increase your scientific culture. It can be of various forms, Lab Meetings, where the last progresses or projects of group members are reviewed and discussed, Journal Clubs, where some papers in the literature are presented and criticized, Conference Reports, where one lucky bastard summarises to the others the amazing talks he/she went to at that last congress in Hawaii (because only the teacher’s pet got to be sent there), or any other form of scientific interaction in groups (acid battles in the chem lab don’t count).

In our lab, we don’t do Conference Reports, because we usually travel in herds – I’m too shy to get to conferences alone – but we do the other types. We have the Ant Club, where we present some interesting papers in Myrmecology (in general on invasive species or community ecology). We have Team Meetings, where we discuss the projects of Master students, the past work of newly arrived postdocs or the latest findings of other group members (plus loads of administrative crap). And we have the Sémibière, which is the subject of this post. Yeah, I know, my introductions are awfully long. That’s just to show you what you should not do.

The Sémibière is a regular meeting held especially for the benefit of students (although we all enjoy it). We had realised that students were especially shy went it comes to expressing opinions in front of the others, mostly because they were convinced that their opinion was crap – or that they didn’t even have one. They were also rather un-motivated by technical papers, like on modelling or stats or such. So we decided to do a different format. First, we remove the “naire” part of the word “séminaire” (French for seminar) and replaced it by “bière” (beer in French). The journal club is held with beers and nibbles, because we know that will attract students as surely as vinegar attracts flies (does it really?). Simple but efficient. When the weather is good, we do it outside – we have an awesome campus and I installed picnic tables for this very purpose.

The other change was to treat only papers of two specific types. The first one is funny papers. Papers that have a real set of scientific features that make their discussion beneficial – approach, structure, methods, presentation, etc – but on a funny topic. We discussed the population dynamics of the Loch Ness monster, the demonstration of Murphy’s Law (when you drop your toast, it always lands on the buttered face), a Capture-Mark-Recapture model of tea spoons disappearing from lab coffee rooms, the Ring Effect (males are supposedly more attractive if they have a wedding ring – a type of honest signal showing that they have been picked up, so are probably higher quality mates), etc.

The second type of papers we discuss in the Sémibière is controversial papers. For example, should we re-wild North America, by introducing the long extinct elephants, lions and giant turtles, or this that an ecological blasphemy? The best-ever-genius-idea or the most dangerous stupidity? We don’t provide the answer, because probably there isn’t a single/simple one, but we present the arguments and confront our various points of view. Controversy helps anyone to have an opinion, or to say why they can’t decide. There, I’ll make a specific post category for these controversy themes, so I can present some difficult scientific controversies and prevent you to sleep forever over these unresolvable existential issues. Mouahahaha!

Sémibière Outside - 13






Ok, my posts are too long, I realise that. And you’ve seen nothing: I’m trying hard to be concise. Well, anyway, that was the message of the day: see how painful it can be when you don’t manage to cut short? It’s the same for your manuscripts: they are too long. Always. Learn to be concise, or you’ll end up like me, with people laughing at you, throwing you stones and rotten cabbage. Be short. Like Tyrion Lanister and like this post.



No post for today. Too tired and still loading…