Differences in size-related ecology and behaviour between vertebrate and in
vertebrate herbivores lead to differences in the rates, tissue specificity,
and spatial distribution of their damage, as well as in their indirect eff
ects. As a result, many features of tolerance to herbivory by these groups
also may differ. Tolerating vertebrate herbivory may demand the ability to
tolerate sporadic non-specific impacts; this may be achieved by broad respo
nses promoting regrowth and resource acquisition. In contrast, the diversit
y of different types of invertebrate damage seems likely to demand a corres
pondingly great variety of responses. These conclusions suggest that tolera
nce to invertebrates may involve a broader set of responses than tolerance
to vertebrates; conversely, the greater specificity of these responses may
make it more difficult for arthropod-tolerant plants to achieve cross-toler
ance to other types of damage.