In a field that is dominated with hydrophones and listening to vocalizations, it is always great when researchers can snap a picture of whale flukes. Many whale individuals, including this blue whale (Balaenoptera musculus) can be identified by unique markings and shapes on their tail flukes.

[Photo by Alycia Drwencke and caption by Karli Chudeau]

Reference

Allen, S.G., Mortenson, J., & Webb, S. (Eds.). (2011). Field Guide to Marine Mammals of the Pacific Coast. Los Angeles, CA : University of California Press.