#!/bin/bash
s="WHITE-TAILED TROPIC-BIRD _Phaëthon lepturus_ (Hawaiian name—koae)"
str=$(sed -n 's/.*\(([^()]*)\).*/\1/p' <<< "$s");
echo "$str"
IyEvYmluL2Jhc2gKcz0iV0hJVEUtVEFJTEVEIFRST1BJQy1CSVJEIF9QaGHDq3Rob24gbGVwdHVydXNfIChIYXdhaWlhbiBuYW1l4oCUa29hZSkiCnN0cj0kKHNlZCAtbiAncy8uKlwoKFteKCldKilcKS4qL1wxL3AnIDw8PCAiJHMiKTsKZWNobyAiJHN0ciI=