Conclusion

Conservation biology is a crisis-oriented science.

• There's a lot we as scientists would like to know about the demography of spotted owls. We may feel uncomfortable making a recommendation because we know how much we don't know, and we don't want to make a suggestion only to be proven wrong.

• A decision must be made now about how much forest is necessary to prevent it's extinction.
  • We are always tempted to say: ``We just don't know enough now. We need to study the problem further.''

  • It sometimes feels as if we are being asked to provide an answer when the data just don't justify it, but

  • Recommending that 10 years of additional demographic data on the northern spotted owl is necessary before any decision can be made is equivalent to deciding now that 10 years of current practices will not doom it to extinction. Deciding to recommend further study is a decision. It is a decision that if there is a problem, we can still correct it later.

  • Type I versus Type II error. As basic biologists the ``cost'' associated with rejecting a null hypothesis that is true is greater than that associated with failing to accept an alternative hypothesis that is true. As conservation biologists, the ``cost'' associated with failing to accept an alternative hypothesis, that there is a population decline for example, may be much greater.

  • We cannot avoid decisions or giving advice. We can only make the best decision or give the best advice with the data that are currently available.

• The vast number of species facing extinction precludes us from gaining a detailed knowledge of more than a few of them.

• Our understanding of natural ecosystems is so limited and the interactions among their components so complex that we can't hope to fully understand them before we start to manage them.

• We'll talk more explicitly about methods for dealing with these uncertaintites later in the course, but they will underlie much of our discussion throughout the semester.

I'm going to argue in this course that biologists have the most to offer to conservation programs when they are:

• Providing rough and ready guidlines for decisions made with little data.

• Identifying what data will be most useful for future decisions.

• Developing adaptive strategies that start out with the small amount of information already available and build on it in a way to increase the chances of success.