Just tamed my first Sinomacrops and named it Monarch. Where I tamed Monarch (And the best place to tame Sinomacrops in my opinion) was at the very bottom center of the island, in that ravine with a river at the bottom. It’s a gorgeous place to set up a hub, and the Sinomacrops are EVERYWHERE. I just put chitin in my last slot, ran toward him, waited until I saw hearts, stopped, crouched, waited for him to fly to me, and BOOM, I got Monarch. They’ll fly off after you feed them, run after them (Don’t get too close), and wait for them to come to you again. DO NOT MOVE WHEN IT’S FLYING UP TO YOU.