In 1920, Arizona introduced bullfrogs as a game species and food source; a century later, the invasive frogs are threatening the Northern Mexican gartersnake |
A pond in southern Arizona can look quiet from a distance. Beneath the surface, though, the balance between species can be very different from what it was a century ago. Among the animals affected is the northern Mexican gartersnake, a wetland-dependent reptile that hunts along streams, ponds and cienegas across parts of the Southwest.Its decline…