Many vertebrate herbivores are also known to select food plants based on levels of tannins and co-occurring nutrients. For example, lambs were less deterred by tannins when these were in a high
quality food source.
In other cases, high tannin levels deterred feeding regardless of the level of protein.
Tannin levels in Eucalyptus are strongly associated with food choice by the common brushtail possum (Trichosurus vulpecula), though not the ringtail possum
It is noteworthy that treating Eucalyptus leaves with polyethylene glycol, which decreases the ability of tannins to bind proteins, caused possums to increase their feeding rates.