Over the past couple of months, have you noticed there are greater numbers of birds around than usual? And not just numbers — an increased variety as well? This is due to the age-old phenomenon of migrating birds. Billions of birds migrate twice per year between their breeding and wintering grounds, creating one of the most astonishing spectacles in nature. World Migratory Bird Day, which is an annual global celebration of these intrepid avian travelers, features the theme “Water: Sustaining Bird Life” and highlights the importance of protecting aquatic ecosystems for birds.