How would an ecologist likely explain the expansion of the cattle egret? A) The areas to which the cattle egret has expanded have no cattle egret parasites. B) Climatic factors, such as temperature and precipitation, provide a suitable habitat for cattle egrets. C) There are no predators for cattle egrets in the New World, so they continue to expand their range. D) A habitat left unoccupied by native herons and egrets met the biotic and abiotic requirements of the cattle egret transplants and their descendants. E) The first egrets to colonize South America evolved into a new species capable of competing with the native species of herons and egrets.