According to an article I found today, dolphins sometimes make whale-like calls. Researchers from the University of Rennes in France recorded dolphins at an aquatic park in Port-Saint-Père and found that they make noises very similar to humpback whale calls, particularly when resting during the early hours of the morning. This is the first time dolphins have been observed mimicking sounds they’ve heard in this way a significant period of time after hearing them.

Apparently dolphins and humpback whales have been observed in the wild interacting with each other in a seemingly playful way, and it’s possible that there is some level of affinity between the two species.