To tell Orcas apart, researchers photograph their growing dorsal fins. Once the whales begin to mature, “this period is marked by rapid growth in the dorsal fin. As the dorsal fin grows it begins to straighten out and lose its earlier curve. This growth is often termed ‘sprouting.’ Growth of the dorsal fin and body continues until the orca is approximately twenty years of age, “(PNOR).
Orcas have a close-knit family structure, and most stay with their mothers throughout life. The Center for Whale Research on San Juan Island estimates that the matriarch of one of the families there is more than 90 years old. Meet her and her offspring in this short video with Charlie.