Butterflies migrating further north

On the East Coast (from NBC News with Brian Williams yesterday) butterflies appear to be migrating north. Species normally appearing there are either dying out or moving further north in to Canada and species normally found in the South have migrated northwards that have not been seen there before. One researcher said that he hadn't seen one of the species ever but this year had counted 180 of that species he had never seen there before. This may be a harbinger of things to come and further evidence of ongoing warming of some areas on the planet. The problem with this is some species like butterflies and birds can migrate to cooler climates but things that don't fly often just die off when the weather changes too much for them. So, unless there are similar species higher up or further north those species soon may become extinct in areas further south. So, I think you likely will see more and more species of all creatures big and small migrating when they can or just adapting or dying off when they can't.