Use the following diagram from the text showing the spread of the cattle egret, Bubulcus ibis, since its arrival in the New World, to answer the following question.

-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.

Question

Use the following diagram from the text showing the spread of the cattle egret, Bubulcus ibis, since its arrival in the New World, to answer the following question.
 
-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.

Quizplus · Accepted Answer

The diagram shows that the expansion of the cattle egret in the New World followed the range of cattle, which provided a suitable habitat for feeding. Additionally, the areas to which the cattle egret expanded were likely lacking in native herons and egrets, allowing the cattle egret to occupy a previously unoccupied niche. Ecologically speaking, this is known as the "empty niche hypothesis," which suggests that introduced species can thrive and expand in areas where there are no native competitors or predators. Therefore, an ecologist would likely explain the expansion of the cattle egret in the New World as a result of the species finding a vacant ecological niche that met its biotic and abiotic requirements.

Use the Following Diagram from the Text Showing the Spread