The hard part is that it goes two ways. Most animals are adapted for interactions within their own species. A seagull is adapted to react a certain way when ano

The hard part is that it goes two ways. Most animals are adapted for interactions within their own species. A seagull is adapted to react a certain way when another seagull screams the same way we smile when someone laughs or get a sense of panic if we hear someone shriek. A seagull has no concept of our behavior really beyond if we move at it in a threatening manner like other potential predators. The most you can do is probably some simple conditional learning akin to dog training considering seagulls in recreational areas have associated beachgoers with potential food source already. Why might a whale speak back to us? Maybe it we chum the water when whales make certain noises they will begin making those noises and expect chum. I wouldn’t call that communication as people expect it to be with ET however. A primitive form of trade perhaps.