Why does the author use the transition "surprisingly"? What does this word mean for the conch?

The author used the transition word "Surprisingly" to register the element of surprise which the tribe showed when the person indicated interest on addressing them.

The tribe has always known him to be an unserious person but was taken unawre by his indication of interest.

Explanation:

The statement where the transition word was used is given below:

"Surprisingly, there was silence now; the tribe were curious to hear what amusing thing he might have to say"