Although I love finding out about how traits supposedly unique to humans are shared by animals, I don’t see how the experiment in this article demonstrates episodic memory in hummingbirds. How is this not the simple sensing (smelling) of the sugar drink in the syringes?

Yvonne Lyerla
Sonoma, Calif.

Researcher T. Andrew Hurly says that his team has tested the birds on arrays of fake flowers, only half of which hold nectar. The animals at first do no better than chance at finding the rewards. “This indicates that they are not detecting the presence or absence of nectar until they probe with their bills,” he concludes .—S. Milius