Why not reach out to your feeders? Isn’t it better to let them know that they are wanted than not? Wouldn’t it ease the transition just a bit more if the students knew for certain that the new music teacher had a place for them?
Basically, encourage your students to have fun with music and with your class. When I surveyed my students, the vast majority said that their favorite thing about my class was my crazy stories. And I actually don’t tell them all that often, but students remember them. This brings them back day after day for another taste of our favorite thing in the world: music!
So that the students feel so at home in your group that their identity transforms from “student” into “musician,” or “violinist,” or my favorite: “orch dork!” You will find that attrition becomes obsolete the more your students identify with your class, your room, and the culture you have created.