Invasive species interactions, diet and personality
How does it all fit together?
I our recent study we’ve been investigating how invasion of brook trout, Salvelinus fontinalis, affects the behavior and diet of native brown trout, Salmo trutta, in Swedish streams. When brook and brown trout live side by side in the stream we have made some interesting observations. We found that the native brown trout adjust their feeding habits — often leading to a convergence in diet between the two species! However this effect appears to be dependent on what the ratio of brook to brown is, because the convergence was not present in the stream where the brook trout outnumbered the brown.
In our work, we’ve also discovered a fascinating link between personality traits and dietary choices: bolder brown trout tend to hold a higher trophic position. This suggests that their willingness to take risks might allow them access to different or more abundant food resources compared to less bold individuals. These results indicate that behavioral variation within a species can significantly influence how individuals adapt when new competition is introduced.
PS. How did we know which fish were bold? Read about it here.
Written by Benedikte Austad, PhD student with the SEG.