For ten points name this marsupial dependent on a few species of eucalyptus trees.
Crusader Cup 2005  Round Seven  Questions by UIUC Academic Buzzer Team, UTC Academic Competition Team, Charlie Steinhice, and James Washick. Editing by Charlie Steinhice and James Washick  Toss-Up #1  Probably because of thousands of years with no natural predators, it has the smallest adrenal gland relative to body weight, and thus has almost no ability to muster the fight/flight response in its own defense. Life-threatening "stress" can be triggered by a dog barking at the base of its tree, which it seldom leaves and from which it receives its hydration as well as food. For ten points name this marsupial dependent on a few species of eucalyptus trees.
Crusader Cup 2005  Round Seven  Questions by UIUC Academic Buzzer Team, UTC Academic Competition Team, Charlie Steinhice, and James Washick.
{koala}s