However, there is a limit as to how much abuse a follower will tolerate. The actions-- or inaction--of the ranger may necessitate morale checks, as determined by the DM. Should a morale check succeed, the follower remains with the ranger. Should a check fail, the follower goes its own way, in most cases never to return. Followers who permanently abandon their ranger are considered lost and are not replaced.
Here are some situations that may result in a follower abandoning its ranger. It's up to the DM to decide when a given situation becomes stressful enough for the follower to require a morale check.
An animal may hesitate to enter an environment radically different from its own. A hawk follower native to the mountains probably won't resist following a ranger into a forest or plain, but it may balk at entering an arctic region. Even if an animal follows a ranger into hostile terrain, it may not remain there for long; for example, a hawk may tolerate the freezing climate of the arctic for no more than a day or two.
Followers trained for combat willingly participate in encounters that may result in injury or even death. However, if the ranger forces an animal to participate in an unrelenting series of battles, resulting in serious damage or chronic fatigue, the follower may rebel and leave. Likewise, if a ranger regularly compels an animal to follow him into caverns, ruins, and similarly dangerous places, the animal may lee.
Though followers usually ind their own food, in certain situations they may depend on their rangers for nourishment. If a ranger neglects to keep a follower fed, the follower may decide to look for greener pastures.
Most followers won't stand for beatings, whippings, or other physical mistreatment. (Being of noble character, most rangers won't administer such punishments, but exceptions do occur.) If the ranger persists in this behavior, abandonment is inevitable.
Some followers, particularly dogs and other domestic animals, have emotional as well as physical needs. A ranger who consistently ignores or withholds praise and affection from his followers risks losing them.
An animal's urge to mate may overwhelm its loyalty to its ranger. An animal may disappear during mating season and never return, particularly if it has trouble inding a suitable partner. Morale checks usually aren't applicable in these situations; instead, the DM may take advantage of mating season to restore balance to the game by eliminating a powerful follower, or getting rid of a cumbersome follower that's proving to be too much of a burden to a ranger.
When certain followers reach the end of their days, due to illness or old age, they may abandon their ranger to die alone (an aged elephant journeying to an elephant's graveyard). Morale checks aren't usually necessary. Instead, the DM may engineer a poignant scene where the ranger realizes that death is near for his loyal companion, and must come to terms with the loss.