Animals have culture-- no one is surprised about this anymore. Birds, primates, elephants, rats, fish, and even ants demonstrate socially transmitted behaviors that fit our definition of "culture." Usually, researchers hypothesize a direct evolutionary purpose behind instances of culture; tools make animals better at gathering food, for example. But what about strange fads in human culture? Is there an animal equivalent to bellbottom jeans, or mullets*?

Recently, researchers observed an example of culture in Orcas that I like to refer to as the Mullet Analogue in Cetaceans. Hal Whitehead and colleagues wrote about a very strange example of culture in orcas known as the "dead-salmon carrying" fad. In a certain pod of orcas, one female started carring around a dead salmon for no apparent reason; soon enough, orcas in her own pod and neighboring pods started copying her. The fad spread like wildfire, and after about 5 weeks, orcas all over town were carring around dead salmon. As quickly as it had arrived, the fad disappeared; it showed up once or twice the following summer (a few orcas were slightly behind the fashion curve), and then was gone forever.

"Horizontal cultures are also found in the suborder Odontoceti, the toothed whales and dolphins. An example is the “dead-salmon carrying” fad of the well-studied “southern resident,” fish-eating, orcas of the Puget Sound area of the northeastern Pacific. It began with a female in K-Pod carrying around a dead salmon in 1987, spread to the other two pods in the southern resident community over a 5-6 week period and then stopped (R. Osborne, personal observation). It was noted a few times the following summer, and then never again." - Whitehead et al. 2004

Why was carrying salmon so popular? Well, why were mullets so popular? Cultural trends don't always make immediate sense, and sometimes a certain fashion is popular only because it's popular. That answer isn't exactly satisfactory, but the good news is that cultural evolution is a hot topic right now (within both human and animal psychology). Stay tuned!

*Some would argue that bellbottoms and mullets increased one's likelihood of mating during a certain era, and this is probably true. But why did our preference for these strange fashions come about in the first place?