Somewhere out in one of the world’s oceans, an enormous female leatherback turtle is hopefully still swimming about without any notion that her name is Sea Biscuit, nor any inkling that I am her adopted mother.

Such gimmicks are common. This week, the Dallas Zoo in Texas advertised a special promotion where visitors could “symbolically adopt a reticulated giraffe for just $89” (about R1,500). They did not say how much it cost to adopt a non-reticulated giraffe...