Most North American hummingbirds migrate to warmer tropical climates in the fall. The Rufous Hummingbird (Selasphorus rufus), shown here, can travel 3,000 miles (4,320 km) from Alaska, British Columbia, and the western United States, to Mexico for the winter. Nectar from flowers along the way provides critical fuel to power the hummingbird’s tremendous migration to and from the tropics each year. Banding studies show that once a hummingbird learns its particular route, it often retraces that same route every year, and will even revisit the same flowering plants as long as it lives. Desert flowers, like this Echeveria subsessillis, play a crucial role in providing hummingbirds with enough energy to complete their long journey. Hummingbirds, in return, serve as pollen couriers between plant populations often located miles apart. This makes the hummingbird a “mobile keystone species” because of their extensive movement over large geographic areas. They have a positive and beneficial impact on the survival and reproductive success of many other unrelated species. These plants and birds rely on each other for survival. Every species has its place in the intricate network of biodiversity and each is a joy to paint.