Missing pets

When I take Zachary and Cowboy for walks, I often see signs for missing pets stapled to the telephone poles around the neighborhood. The vast majority of them read about the same: "Beloved dog missing since Sunday night", "Help me find my tabby cat", etc. Lately, however, there have been a couple unusual signs. Yesterday I saw several signs for a missing parakeet (he answers to "Sweetie"). Today I saw a sign for a missing Turtle named "Escapé". Which I suppose is appropriate. But how exactly does a turtle go missing? Did he run away?