Dolphin Watch
Real rather than random
By ANN WEAVER
Article published on Thursday, Aug. 7, 2008
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![[Image]](/content_images/080708_out-01.jpg) |
| Photo by JOHN HEIDEMANN |
| Little Laska, one of the newest bottlenose dolphins, squirts around the seas with its mom. |
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Not that I needed convincing that dolphin relationships are real rather than random, however complex they might be, but it was so neat to see two episodes one day that made that all so clear.
If bottlenose dolphins are famous for anything, it’s for their fission-fusion society. This is a term for their marked complexity of social interactions, which in totality make up relationships and ultimately the mosaic of social life at sea.
Maybe we’re fascinated with their relationships, as flowing as the sea itself, because we’re fascinated with our own. Humans manage amazingly complex webs of friendships, acquaintances and business associates, especially now that you can have several billion new friends through the Internet.
Indeed, human e-mail is like two dolphins whose entire relationship is based on trading vocalizations across vast murky distances. Who says those aren’t just as real.
Both of this story’s episodes began with the same social situation: a lone dolphin hunting and a group of dolphins happening by. In the first episode, the lone dolphin was avoided. In the second, the lone dolphin was patently not.
The first lone dolphin, Scrapefin, worked an apparently productive patch of deep water bordering a shallow sand mesa. The local tidal current, itself famous for strength, must’ve swept steady opportunities his way. He dove vertically between no-nonsense surfaces, mostly out of sight.
Scrapefin is a local boy. He’s consistent. He inhabits a remarkably small area of water, which if he never left (unknown but unlikely), would make the smallest home range of any dolphin here. He’s usually alone, an inexplicable habit given the substantial shark scar on his tailstock. He socializes mainly with other young bulls.
Scrapefin wasn’t the only thing haunting the deeper waters: three loaded construction barges were tethered nearby. Through no fault of their own, the barges staggered stolidly across a heretofore-popular but very narrow channel, now mostly eschewed by boaters and dolphins alike.
But dolphin habits die hard, it seems, and mothers with new calves are particularly apt to roam the channels of this local labyrinth.
By and by, five mother-calf pairs came up the channel around the barges. It was great to see new babies PeeWee, Qball, Laska and Dose squirting around moms P, Q, LA Stick and Leading Dent as X and Little X slid alongside.
When the nursery group rounded the middle barge, 80 feet or so from Scrapefin, one of them chuffed a couple of times, a coughing vocalization with multiple meanings. Abruptly, the group reversed course and retraced its steps.
The reversal was definitive. All seemed in complete agreement. There was no free-form period of wandering that suggests individual ambivalence about a behavior change like this. They left without further apparent interaction with Scrapefin.
Scrapefin didn’t appear to change his behavior one iota.
It was the kind of observation that drives me to the database to ask how often, if ever, we’ve seen Scrapefin in the company of these new moms; one would suspect very little. I know he swims the seas adjacent to X and Little X.
We paralleled the enchanting nursery group for a time before stopping to retrieve some sea bounty: deck chairs that probably blew off a passing yacht. We collect all the manmade debris we find, especially any that would damage a boat hitting it at speed.
We retraced our own steps to resume the survey route. Scrapefin was still there hunting.
Half a mile away, another lone dolphin hunted. It was Bet. She specializes in bottom feeding, poking food out of the seabed. Like Scrapefin, she was wholly occupied. At a distance, we watched her work plumes of silt ascending to the surface.
By and by, another little wad of dolphins came into view like the nursery group who’d avoided Scrapefin. They had several choices. They could continue past without pause, swing left to the little mangrove island, or swing right into Bet’s cove. They could ooze past her, disperse to search the general vicinity, or approach her without pause, which is what they did. They turned and swam, directly and unhesitatingly, all the way across the cove right up to Bet.
Dolphins don’t have ‘family’ in the human sense of mom, dad and the kids, but they certainly have relatives and close friends. The new group was both. Two of the three moms had their calves with them. The reunion with Bet completed that picture. Bet’s mom Tanks was there. Tanks’ good friend Face was there with her 2-year-old Babyface. Valiant was there with her new little Vice, just six weeks old, and older calf VC.
As clearly as the Scrapefin situation was separation, this was clearly reunion.
The little group of moms and kids meandered around the modest cove, winding and swirling around one another for a long time. Every time Bet surfaced, tiny Vice surfaced at her side like it did with its own mom Valiant. It’s gratifying to say “every time” in conjunction with dolphin behavior because that kind of consistency is just so rare.
You could see Bet petting the tiny calf with her flukes. Undoubtedly, underwater and out of view, she would pet it with her pectoral fins, with long gentle slides along the baby’s body and perhaps a cuddly cheek rub for good measure.
Like I said, I didn’t need to be convinced that dolphins have real and important relationships out there, despite the amazing fluidity of their social lives. But it was such a privilege to see their worlds so clearly for once.
On the other hand, chuffs DO have several meanings, only one of which is “Get lost!” IF the chuffs meant ‘get lost’ that day, they may have meant the boat, not Scrapefin. Too bad I couldn’t tell who chuffed. The ‘clear’ observation of avoidance did send me scurrying to the database to generate coefficients of association for the 76 surveys so far in 2008. An index of 40 percent or more means a close association. As expected, Scrapefin is enormously chummy with X and Little X (84 percent). But he’s also tight with Q (73 percent) and P (52 percent) though less with Leading Dent (30 percent) and LA Stick (27 percent). However, that changed with the emergence of the calves. IF they avoided him, is that why?
Dr. Weaver studies wild dolphins under federal permit GA1088-1815, National Oceanic and Atmospheric Administration. Send her an e-mail at aweaver@argosy.edu or visit www.dazzlingdolphins.com.
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Article published on Thursday, Aug. 7, 2008
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