A small flock of Snow Geese, Anser caerulescens, take off from a pond in the Bosque del Apache National Wildlife Refuge in New Mexico, USA. The two birds in the lead with white heads and dark bodies are Blue Phase Snow Geese, whereas the all-dark birds are juvenile or immature snow geese. The white birds with black wings are normal adult snow geese. The birds remaining on the water are a mix of mostly snow geese with a few Ross's Geese, Anser rossii.. (Photo by: Jon G. Fuller/VWPics/UIG)