for Night of the Bat by Paul Zindel
Deep in the Amazon jungle, members of an elite scientific team are disappearing and Jake gets word his dad is in grave danger. So Jake makes the journey into the remote jungle where he finds most of the team's mutilated bodies. They've been slaughtered by a bat-like winged creature that's now stalking Jake and the remaining survivors. What chance can Jake have to survive against this giant bloodthirsty winged beast?
Publisher description retrieved from Google Books.