Scott Kraus/New England Aquarium
Photo-identification, the process of using photographs of natural markings to distinguish one individual animal from another, is the foundation of most modern whale studies (cetology). Many whale species have a physical characteristic that is unique for each individual of that species.
- In humpback whales, it is a black and white pattern on the underside of the tail, or flukes, as well as the shape of the dorsal fin.
- For sperm whales, researchers use the profile of the scalloping along the trailing edge of the flukes.
- And for right whales, it is the distinct pattern of the callosities (raised tissue) on the top of their heads. See how it works in detail or look at a matching example.
Researchers who study each species take photographs of these features and then compare them to photographs in a catalog to determine when and where that individual was seen before. As these photographs of a particular species are collected from different areas over time, researchers monitor population demographics, mortality, reproductive success, ocean habitat use patterns, trends in health and rates of human-caused scarring. These data can be used to discern population-wide problems, develop recovery strategies and evaluate the impact of management and conservation efforts.
Photo-identification studies have been particularly important for understanding the plight of the North Atlantic right whale, which endured nearly a millennium of whaling before becoming protected in 1935 by a League of Nations resolution.