I imagine a Ranger and Druid would make an excellent scouting team. Druid flies above while Ranger scouts below. Ranger casts Speak with Animals, to occasionally communicate with Druid (can even be cast as a Ritual, so 10 minutes to cast and no spell slot used). If Ranger gets in trouble the Druid can fly back to get help.
Perhaps the Bard in the party casts Speak with Animals, talks to the Druid in their bird form, and the Druid can then fly back out again without ever changing into their humanoid form.