Dr Marion Germain

My research interests revolve around behavioural ecology. I have worked on topics such as mate choice and mate choice copying. But since my PhD, I focused on understanding a specific behaviour: dispersal.

Understanding the causes and consequences of dispersal
Dispersal, a key life history trait, involves moving from a natal site to a breeding location or between consecutive breeding sites. While offering benefits like inbreeding avoidance, it is costly. Dispersers leave familiar environments for the unfamiliar, risking predation and challenges of finding resources and suitable breeding grounds. Less obvious are the trade-offs; time and energy spent moving and looking for a breeding habitat means less for other essential activities such as foraging and seeking mates.
Despite costs, dispersal is widespread across taxa. Yet, the interplay of costs and benefits and their fitness consequences are poorly understood, limiting our grasp of the evolution of dispersal.
My PhD aimed to dissect these costs, benefits and resulting fitness consequences. I studied a wild population of collared flycatchers, a small passerine bird, in Sweden. By analysing long-term data and conducting experiments, I gained insight into the costs and benefits tied to dispersal. We revealed that dispersal can not only affect individuals immediately but have lifetime consequences. Remarkably, notable costs occur even before settling for reproduction, an often-overlooked aspect. For those overcoming these challenges, dispersal seemed adaptive.
Since my PhD, my research interests evolved while maintaining a central focus on unravelling dispersal strategies by delving into their causes. Habitat selection is crucial, but the cues guiding dispersers’ choice are unclear. By combining long-term data and fieldwork on a population of long-tailed tit just outside Sheffield, we showed that dispersers move towards attractive habitats, indicating reliance on environmental cues to predict breeding habitat quality.

Behavioural and applied ecology: how to combine both?
Using my background in behavioural and avian ecology to applied ecology. The spruce budworm is a defoliating insect native to North America causing large-scale outbreaks with associated important forest mortality. Early detection of outbreak hotspots has proven difficult. I investigated whether animal sentinels, specifically insectivorous bird species, could be used to monitor and detect increases in spruce budworm populations. We found that all three species investigated responded but one species responded three to four years before the insect population could be detected by current monitoring methods. Early detection is a critical step in the management of spruce budworm outbreaks and bird populations could be used to identify future epicentres of spruce budworm outbreaks.