Tens of thousands of small barriers hamper fish recovery in the northeastern United States. But while the demolition of big dams out west gets the most attention, a similar revolution is revitalizing northeastern streams and rivers—one tiny dam at a time.

Dam removal is often described as rewilding rivers, but it also liberates the human imagination, the latest installment in Ben Goldfarb's Wildlife at the Crossroads series.

Three varieties of "vegan Dracula" plant-eating lampreys found in unlikely places. Scientists are working to determine the full range of the ancient and elusive creatures that have lain hidden for 150 million-odd years.

With its suction-cup mouth and circular rows of sharp teeth, a close-up view of an Australian brook lamprey is rather frightening. But unlike many bloodthirsty lampreys around the world, this species prefers a plant-based diet, gobbling up organic matter on creek beds instead.