30．Keen observers and quick learners，they are astute about the intentions of other creatures，including researchers，and adept at avoiding them．

(并列同位语keen observers and quick learners)

乌鸦是敏锐的观察家和快捷的学习者，它们对其他生物(包括研究人员)的意图感觉非常敏锐，并且善于躲开它们。

分句1. they are astute about the intentions of other creatures，including researchers

分句2. andadept at avoiding them．