The Bosque del Apache National Wildlife Refuge in central New Mexico is a safe habitat for birds migrating in the winter from the northern reaches of North America to the southern states and Mexico. Food is plentiful because of nearby grain fields. The refuge is especially known for its large populations of Sandhill Cranes and Snow Geese. The cranes roost in the ponds of the Bosque, leave in the morning in small groups heading for the grain fields, and return, again in small groups, to the ponds in the late afternoon and early evening which provides ideal light for photography. Snow Geese leave the ponds at sunrise with the whole flock taking off at once, honking loudly on their way to the morning feed in the fields. Like the cranes, the Snow Geese return to the ponds in the afternoon and early evening but arrive in larger groups.
The challenge for photographers is capturing images of these birds in flight, especially in the low light of early morning and late evening. It requires a long lens, 400-600 mm, and a tripod with a ball head so that the camera can move steadily with the flight of the birds. Focusing on flying birds is problematic, but modern cameras have continuous autofocus as an option, and the ability to shoot 3-10 frames/sec in the burst mode. The ideal shutter speed is 1/1000 second; in low light this will require a wide aperture and an increase in ISO. Even with all the modern technology, the learning curve for capturing birds in flight is steep, but a tremendous amount of fun.