When wildlife TV personality Forrest Galante sat down for his monthly call with YouTube consultant Paddy Galloway, he received some bad news. No more turtles. Galante has 2.5 million YouTube subscribers . He's been producing wildlife programming for more than a decade, including a docuseries on Animal Planet and a show on the History Channel. He owns his own production company. Generally speaking, Galante's got a good feel for what his audience wants.  But it was Galloway, something of a guru in the still-burgeoning YouTube creator economy, who identified that whenever Galante showed turtles in his videos, viewer engagement dropped. It was consistent and significant. "Maybe it's just turtles are more commonplace and they're kind of slow and they don't really do much," Galloway said in an interview.…