By Anna Lippold, a PhD student at McGill University

Just a few weeks before Christmas 2023, I travelled to Northern Ireland to participate in the Annual Meeting of the British Ecological Society (BES); funded by a QCBS Excellence award. The BES is a large society composed of ecologists not only from Great Britain and Europe but spanning the globe(heck, I even met someone who travelled from Japan!). For those of us who travelled from afar, we were often met with the sincere exclamation, “You really came all the way [from Canada] for this?”.  A thousand plus researchers presented their research there, in sessions ranging from classic ecological fields like population dynamics and species dispersal to emerging fields like urban ecology and rewilding. Apart from the excellent talks from scientists, we had one plenary speaker, Isabella Tree, walking the audience through one of the first (or the first?) occasion to consciously turn farmland in the UK into wilderness by letting plants grow wildly and introducing larger herbivores like horses, deer and pigs that represented a pre-Anthropocene fauna. The room was packed, the talk inspired, and later sparked heated debates in small groups about whether it is ethically ok to allow non-native species in a rewilding project (Isabella says yes, “we are not precious about invasive species, if an ecosystem is strong enough, they won’t have much impact anyways”), and why no carnivores are introduced into these rewilding project, or, why, in Europe or the UK, it is so awkward to discuss animal population control (e.g., hunting).

At the conference, I had the opportunity to present my own research that explores the drivers of variation in spatial behavior within a population. To answer this question,  I studyI a quite spectacular breeding colony of Ring-billed gulls (Larus delawarensis), where about 33 000 pairs breed yearly on a small island in the St-Lawrence just north of Montreal. Using GPS data from tagged birds, we’ve found a large spectrum of spatial behaviours, from some birds stay close to the colony, foraging at one (or very few) locations (often landfills or dumps), to others feeding up to 70 km away from the colony, travelling in intricate patterns over the vast agricultural fields outside Montreal.  It is not quite clear where this variation comes from – is it that some birds have better spatial memory than others? Or a better sense of navigation? Do they have differences in the brain related to spatial abilities? Are anthropogenic contaminants and heavy metals affecting their brains to different degrees? Is it competition, allowing more bold and aggressive birds to defend closer, potentially better foraging sites, while the shyer ones have to avoid the bullies and go search elsewhere?

At the BES conference, I presented research that examined whether there are differences in navigational ability between birds, and whether that would drive differences in how the birds would naturally move through space. To test these questions,  last spring I took a bunch of ring-billed gulls from their nests, equipped them with finely tuned GPS loggers, and drove them almost 100 km eastwards of their colony, where they were released and tasked to find their way back to the colony. This experiment was excellent fun (at least for me!), some birds flew back in an almost straight line, while others got very, very lost (although don’t feel bad, every single one of them made it back to their nests within a day). There was more variation in how my birds mastered this task than I expected. However, contrary to my hypothesis, their ability to navigate from an unknown location did not predict how they would move through the landscape naturally for foraging. This could suggest that foraging decisions are influenced by a number of factors, of which the ability to navigate unknown terrain is not the strongest. Following my presentation, I was quite frankly very (positively) surprised and almost overwhelmed by the interest and helpful suggestions I received. I left my session with a list of ideas of what else I could include in my analysis, and a list of people whose research I can study to better understand how and why birds navigate (I’m actually very new to this topic). Truly one of the most rewarding conferences I have participated in. And there was beer. Guinness of course – and a friendly waiter told me in no uncertain terms that it was not alright, actually rather an insult, to mix Guinness with cider, as I’ve seen (and enjoyed!) in some of Montreal’s Irish pubs. Alright, Sir! Sometimes you even learn something about the place you come from when you travel…

About the author: Anna Lippold is a PhD candidate at McGill University, studying potential drivers of variation in spatial behavior in ring-billed gulls, such as neuroanatomy, contaminant exposure and navigational ability. Before starting her PhD, Anna studied how foraging ecology changes trends of environmental contaminants in polar bears in Norway.