The architectural design of trees protects them against large herbivores

International audience1. Where large browsers are abundant, the survival of trees depends upon their ability to deploy defences, either chemical or structural. Structural defences include the arrangement of dense and intricate architecture, termed ‘cage’ architecture. Previous studies showed that trees developing in herbivore-rich environments tend to have more cage architecture but its precise effect on mammalian herbivores remains unknown. 2.In this paper, we experimentally test how cage architecture affects the bite rate of goats, a generalist mammalian herbivore. 3.We selected 11 palatable tree species with contrasting architectures. We described their caginess using an index combining spinescence and woodiness of their stems. Lastly we evaluated how the caginess of trees slows down herbivores when feeding on the inner leaves in tree crowns. 4.We observed that the bite rate of goats on inner leaves of the cagiest trees was so severely reduced that they could not satisfy their daily nutritional requirements. We discuss how this could affect the preference of wild herbivores for less cagy trees, especially at the end of the dry seaso