Read these two sentences:

The research indicates an increase in the number of eagle nesting sites in the Southeast.

Eagle numbers overall are dramatically declining each year.

Which transition word correctly links the two sentences?

a. Additionally

b. Consequently

c. Furthermore

d. However

e. Incidentally

The correct answer is D. however.

You want to show contrast between these two sentences, and the only word among these which can do that is however. The sentences are each other's opposites - even though there is an increase of eagles in the Southeast, there is still a decline in their numbers overall.