Bottlenose dolphin bulls form partnerships called alliances, but that doesn’t keep them from skirmishing with others and getting tooth rakes like these on the dorsal fin of a local bull.
There's plenty of ways to get information these days. Who isn't easily swept into the swift currents of Internet information?
Some of us still prefer to submerge into the stillness of a dim library while more contemporary types are absorbed by digital books. But regardless of how you seek information, good investigation takes time, so it helps to find informants.
I feel extremely fortunate to have 300 great informants among the dolphins outside your doorstep.
One winter morning at sea, Capt. John Heidemann and I caught sight of the battered dorsal fin of a large bottlenose dolphin speeding past. The fin traveled steadily, mostly underwater, from the Intracoastal Waterway through John's Pass and into the Gulf of Mexico beyond.
It was Midface, a local bottlenose dolphin bull we've known since the beginning of our study. As we watched him streak into our giant sea of a backyard, his look of a lone dolphin at speed belied his true identity as the steadfast informant he’s been in our study of bottlenose dolphin social psychology.
For example, he appeared to be alone, a simple observation that was loaded with meaning. We spent some time looking for dolphins in his vicinity, perhaps trailing him as dolphins do, but didn't see anyone.
We were particularly looking for a bull called Lax, whose been Midface‘s near-constant companion since 2010. Although Lax wasn't around, we’d see him later that day in a chaotic convergence of three different groups of dolphins. Midface would not be there.
Midface’s apparent solitude was a good reminder to apply generalizations about animal behavior with care. The scholarly literature on bottlenose dolphins, for example, will tell you that male bottlenose dolphins form a strong bond with another male dolphin sometime during their adulthood that can last a lifetime.
Formally, these bonds are called alliance formations. Bulls that have formed an alliance are typically found together and said to use their collective bulk to outcompete single bulls.
Yet one would suspect there's more to the story.
In the last decade, Midface has formed three fairly loose alliances. He spent a couple of apparently successful years bonded with local bull N, as together they challenged a number of other alliances (Dolphin Watch’s The brass ring). But then he switched alliances to a bull who probably lives in the Gulf of Mexico, whom we call Ilex (Dolphin Watch’s Passing along a parallel).
In the last couple of years, Midface switched again when he began appearing regularly with Lax; they too do things together that neither bull has been seen doing alone (Dolphin Watch’s Do we really need the night to appreciate day?).
Thanks to informants like Midface, we’re doubly encouraged to take generalization about bottlenose bull alliance formations with a grain of salt, similar to how we (should) take the "happily ever after" part of human marriage with a grain of salt.
Like marriage as a metaphor for bull bonds, Midface’s series of alliances suggests that maintaining a close association takes a great deal of social flexibility, especially when both partners are big bulls with big attitudes. That bottlenose dolphins even attempt such relationships at all is a shrine to their advanced social capabilities.
Another way Midface serves as informant is his demonstration that bottlenose bulls often return to local waters with strange new females.
At the time, of course, we don't know that the bull’s schoolmates are females unless and until they return with newborns at some later date. But many are because they do.
Currently we’re watching for the strange schoolmates who swam through John's Pass with Midface in June 2010, Sunday and Bliss, the latter with the most memorably mangled dorsal fin I’ve seen to date. This is fieldwork. Time will tell.
As informant, Midface revealed that bulls may have not just bond with other bulls. A bull can sometime show a preference for a particular female, perhaps akin to the bonds their form with other bulls though briefer (and for different reasons), which defies the bottlenose reputation for rampant promiscuity.
If we see female Osiris, named after the Egyptian god of munificence, we’re very likely to see Midface as well. He swirls and rolls in her immediate vicinity, rarely moving more than a dozen yards from her side.
With 300 great informants among the dolphins outside your doorstep, I’m easily swept into their swift currents of information. Thanks for riding along.
Dr. Weaver studies wild dolphins under federal permit 16299, National Oceanic and Atmospheric Administration. Send her an email at firstname.lastname@example.org or visit her website www.dolphinsuperstore.com. NOAA advises anyone who sees a stranded dolphin in the Gulf of Mexico to call 877-942-5343 or 877-433-8299.