A recent article (hyperlink below) suggests that the male freshwater dolphins (Inia geoffrensis) that Heather and I got a chance to see in Peru this year (photographic evidence above) hold and thrash objects at the surface to “impress” females. What’s particularly interesting is this quote from the researcher:
“It’s particularly interesting that the complexity of this behavior in these dolphins is considerably greater than that in chimps,” Martin said. “Chimp males break off branches, thrash them around and make a lot of noise to show off how macho they are â€” bit like blokes with big motorbikes and Ferraris, I guess. Botos, however, are much more subtle, and often use their objects in what appears to be a ritualistic way.”
The complexity of the act sounds intruding.