Dolphin Watch
Muscling mom for her fillet, not
By ANN WEAVER
| Article published on Thursday, July 2, 2009 |
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Why can’t we feed zoo animals anymore? When I was a kid, people tossed all kinds of things at monkeys and bears to eat. I liked the action it created.
Not any more. Feeding zoo animals is strictly forbidden. I myself grew up to be one of those nasty people who went around ruining the fun of feeding animals by sternly instructing zoo visitors on the hazards of feeding. “Only the biggest one will get the food. The rest will just fight,” I explained endlessly. “Plus, marshmallows really aren’t that good for bears.”
Was I just out to ruin a day at the zoo? No. Feeding captive animals is bad for many reasons, not the least of which is that people tend to make poor choices about what to feed zoo animals. The main reason is that it makes animals fight over the food, a literal demonstration of contest competition. Fighting over food is something we take as axiomatic.
For most species, fighting over food IS axiomatic.
Yet, last Sunday, a mother dolphin and her calf new to these parts toyed with the leftovers from a large filleted fish long enough for eleven resident dolphins to pass by without a whiff of conflict. Doesn’t that go against biology in its purest form?
Do dolphins get credit for a unique social psychology or was it just contextual?
Ok. The dolphins in question are not captive. One could argue that because they’re free-ranging, they can find their own food easily and therefore don’t have to wrestle it from others. On the other hand, if finding food is so easy, why do the dolphins in our local waters devote so much time to the task?
Given the identity of the eleven dolphins who inspected the strange mother and her fillet, there were many reasons to expect a fight.
Bet and her mother Tanks were the first to pull up. They approached the new mom directly. Bet was more interested in swirling around the calf, jetting by it at speed to sweep it into her jet stream.
Tanks is another story. She has a funny jaw and the curious habit of swimming with her mouth slightly open. I think she broke her jaw in the past and it healed off center. Her open-mouth swimming style reveals deeply worn teeth. Combined with her slow steady style, Tanks appears to be older. I often wonder how she gets enough to eat. With her daughter’s support, couldn’t Tanks have absconded with the fillet?
There were also two other mothers with calves to feed. Presumably, such mothers need extra nutrition. Keyhole Notch is nursing her little month-old calf and, conservatively, will be nursing for the next two years. But maybe she couldn’t afford a fight because her calf is still so little (and vulnerable).
That wasn’t true of the other mother-calf pair, DD1 and Doodle. A resident dolphin with a split fin, DD1 appears to have fairly high social standing among local dolphins. In other words, she gets her way when she presses a point. On the basis of social standing alone, it seems DD1 could have contested possession of the fillet with the strange new mom.
DD1 was undoubtedly interested in the fillet, swimming directly to it. But when she and the new mom surfaced again, the new mom still had the fillet. DD1 swirled back to Doodle, Tanks and Bet.
The lone fin haunting the vicinity turned out to be N. N is a local bull. Captive studies suggest bulls out-rank females (though I have some doubts about the generality of this). Even if dolphin social standing didn’t matter, which is like saying human social standing doesn’t matter, N could have muscled the fillet away from the mom because he’s bigger.
But nothing N did suggested he challenged the new mom for her fillet, though he went on to feed with Bet for the next half hour in a nearby bay.
Another contingent of the eleven dolphins who passed by the munching mom was a quartet of big bulls Grin and Twin Dip, female Face and two-year-old Babyface. Like the others, they cruised close by the munching mom.
Conventional wisdom, which I have no reason to doubt, is that bonded bulls like Grin and Twin Dip out-compete solo dolphins. A coordinated assault by two bruisers who collectively out-weighed the strange mom by at least 200 pounds could have, it seems, easily harried her into abandoning the prize.
Apparently, the entire quartet was disinclined. After a short inspection of the munching mom and her bobbing fillet, they continued on.
Maybe that was because of Face. Back in season, she’s been in the company of many different bulls the last couple of months. Maybe today’s big bulls were too riveted on her to eat (another axiom). On the other hand, I’ve seen them stop to eat while escorting other females.
Either the new mom was a worthy opponent, our dolphins don’t like leftovers, or this was yet another example of the dolphin non-harassment policy called ‘respect for the possessor’. How did their live-and-let-live attitude emerge? Is the sea really so plentiful? Can that be the reason? Don’t humans live in a world of plenty?
Dr. Weaver studies wild dolphins under federal permit GA1088-1815, National Oceanic and Atmospheric Administration. Send her an e-mail at dazzled@tampabay.rr.com or visit www.dazzlingdolphins.com.
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Article published on Thursday, July 2, 2009
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