Infer the meaning of the word Harbinger based on the context clues provided in the paragraphs.
Paragraph 1 (Character Reaction): When the birds suddenly migrated early, farmers muttered that winter would arrive soon.
Paragraph 2 (Cause and Effect): Because the storm clouds thickened rapidly, sailors prepared for rough seas.
Paragraph 3 (Contrast): While others dismissed the strange quiet, she sensed it signaled a major shift.