Does any creature wait more patiently than a dog? Some dogs wait for hours for their humans to come home, listening for the sound of a footfall, a car engine, a key in the lock. Dogs know how to wait because they must. They have thousands of years of practice at it.
Some dogs are famous for waiting, like Hachiko, an Akita who is still remembered in Japan for appearing at a train station every evening for nine years to wait—in vain—for his person. And then there's Argos, the most patient dog in literature, who so yearned for one last glimpse of his beloved master that he waited 20 long years for Odysseus to finally come home.
This beautiful saluki didn't have long to wait until her human came out of the grocery store, but with her chin resting on the seat back, eyes fastened on the door of the market, I could tell she was prepared to wait an eternity, if that's what it took.