PhD defence Jakob Gismann

Jakob Gismann (TRÊS/EGDB/ConsEco)

Promotores: Prof. F.J. Weissing, Prof. A.G.G. Groothuis; copromotor: Dr M. Nicolaus

The eco-evo-devo of stickleback personalities

The term ‘animal personality’ refers to the phenomenon that in virtually all animal species, individuals differ systematically and consistently in their behaviours. These differences can have important eco-evolutionary implications. In my PhD project, I studied personality variation in three-spined sticklebacks from an integrative developmental, ecological, and evolutionary perspective. As controlled field experiments in aquatic environments are difficult and behaviour under lab conditions often lacks ecological validity, we developed a seminatural experimental mesocosm system where large groups of sticklebacks could be followed individually over extended periods of time.

In a number of experiments, we investigated how social and ecological conditions can shape behaviour over different time scales and how personality differences, in turn, can affect ecological processes. We showed that a brief history of isolation (~60 years) was sufficient to induce divergence in movement behaviour between two stickleback populations and that individuals’ behaviour can be affected by the composition of their social group, but to a lesser degree than often concluded from the lab. We also investigated the consequences of personality variation for dispersal and found that certain personality types may facilitate movement and establishment in novel environments. Furthermore, we found that social environmental conditions experienced early in life may affect social associations later in life.

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