Final answer:
Sentence (1) is a good supporting sentence as it provides important timing details for the migration event of sandhill cranes, which is relevant to the main topic of the paragraph.
Step-by-step explanation:
Sentence (1), which states that the cranes arrive between mid-February and April, is a good supporting sentence. It ties directly into the main topic of the paragraph, which is describing the annual migration event of the sandhill cranes to Nebraska's Platte River Valley. The sentence helps to establish the timing of this spectacular wildlife event, providing context and relevance to the phenomenon being described. Understanding animal migration patterns is critical for conservation efforts and for appreciating the natural cycles that many species, such as sandhill cranes, undergo as part of their life history strategies for survival, including searching for food, breeding, and maintaining body temperature.