"Cooooooommmmmmmeeeeeeeee heeeerrrrrreeeee . . . . Momma dolphin has something to say".

Mother dolphins shift their signature whistles to higher frequencies and have larger bandwidths when calling to their dependent calves during separations involving stranded health assessments compared with separations when the calf is absent. While this shift may reflect a version of "child-directed communication," more research is needed to understand the parameters and function of this phenomenon.