How social environments affect selection on animal behavioural types
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Final Report Abstract
This DFG-project allowed me to establish a long term study for years to come to answer ecological and evolutionary questions related to behavioural expression in different social environments. In my project, the two main goals were to i) build and establish an automated surveillance system, which would allow to collect information about behaviour, social interaction and life-history form insects with unseen detail and ii) to find out whether social environments affect the behavioural expression and fitness and, whether behaviours affect survival at the individual level, by using field crickets. I managed to reach both goals. I revealed that individual level behavioural expression (i.e. boldness) explains individual variation in longevity in the wild. I also showed that at the population level the local density of males affect the fitness of the focal male, following the pattern predicted by the Allee effect theory (Niemelä et al. unpublished manuscript; attached to this report). I also showed that the effects of the local density on fitness vary at the individual level, revealing individual variation in reproductive tactics in the wild. Finally, this variation in reproductive tactics explains longevity. These are important contributions to ongoing discussion about the ecological and evolutionary consequences of individual variation in labile traits in the wild. On the theoretical side, I reviewed the mechanisms which can explain short and long term social partner effects on behavioural expression both among- and within-individuals. Finally, I revealed potential sources of bias in the general methodology used to sample behaviours in the wild. I showed that environmental variation can bias the individual level parameter estimates, and thus lead to biased ecological and evolutionary interpretations, if this environmental variation is not taken into account either within the experimental setup or in the statistical models. In summary, the present DFG-project allowed me to update the biological, theoretical and methodological background in behavioural ecology research focusing on social interactions and social environments.
Publications
- (2015) Personality-related survival and sampling bias in wild cricket nymphs. Behavioral Ecology. 26, 936-946
Niemelä PT, Lattenkamp EZ, Dingemanse NJ
(See online at https://doi.org/10.1093/beheco/arv036) - (2015) Social carry-over effects on non-social behavioral variation: mechanisms and consequences. Frontiers in Ecology and Evolution. 3, 49
Niemelä PT, Santostefano F
(See online at https://doi.org/10.3389/fevo.2015.00049) - (2017) Individual versus pseudo-repeatability in behaviour: lessons from translocation experiments in a wild insect. Journal of Animal Ecology. 86, 1033–1043
Niemelä PT, Dingemanse NJ
(See online at https://doi.org/10.1111/1365-2656.12688)
