@fBoyle-- That's a good question.
These are two different styles of leadership. The basic difference between the two is that behavioral leadership theory says that in order to be a good leader, an individual requires specific characteristics. It's a "one-size-fits-all" idea for leadership.
Contingency leadership theory, on the other hand, says that there is no single leadership type for success. It completely depends on the situation and the environment. While one individual with a set of characteristics might be successful in one environment, another environment will require a leader with different characteristics.
So you can say that the behavioral theory is a rigid style of leadership and contingency, more flexible.