This picture shows two different species of vultures at roost. The bird with its wings spread is a Turkey Vulture (Cathartes aura) and the other 3 birds are Black Vultures (Coragyps atratus). It is not uncommon for these two species to associate. According to All About Birds (Cornell Laboratory of Ornithology) black vultures have a less acute sense of smell than the turkey vulture so they hang out with them and follow them to food sources. This picture was taken on a cool morning and the turkey vulture has spread his wings to absorb more sunlight and warm up. On cool days, the vultures take their time getting off the roost because they depend on thermals to help them climb to the heights with minimal expenditure of energy. So, they wait until the sun has been up long enough to produce them.