Marianna Riipi

TL;DR: Seasonal patterns in allocation to growth and putatively defensive compounds in the leaves of mountain birch and co-occurring changes in physical leaf traits and concentrations of several compounds indicated a seasonal decline in foliage suitability for herbivores.

TL;DR: The results show that grouping would have been highly beneficial for the first aposematic prey individuals surrounded by naive predators, because (1) detectability risk increased only asymptotically with group size; (2) additional detectability costs due to conspicuous signals were marginal in groups; and (3) avoidance learning of signal was faster in groups.

TL;DR: The gradual-change hypothesis does not provide an easy solution to the initial evolution of aposematism through predator learning, but the possibility remains that cost-free step-wise mutations over the range of weak signals could accumulate under neutral selection to produce effective strong signals.

TL;DR: Assuming that phenolics affect herbivore preference and performance, different plants may suffer damage at different times of the growing season, and the overall variation between trees in the fitness consequences may be low.

TL;DR: The generally small impact of clipping on herbivore performance suggests that the low intensity of natural browsing at the study area does not have strong consequences for the population dynamics of insect herbivores on mountain birch via enhanced population growth caused by browsing-induced changes in food quality.