Caught mid-chomp swallowing a fish, 3-year-old bottlenose dolphin Vidalia demonstrates his fledgling fish handling abilities. Dolphin calves like Vidalia that are injured as young calves stay closer to their moms longer and as a result postpone some of their lessons at sea school. But this picture shows that Vidalia is developmentally on schedule.
Here is a little fable. Imagine walking down the street from one end of your block to the other one. You saunter leisurely. No traffic hampers your stroll. The entire street is visible.
There is another person all the way at the other end of the block. The two of you walk towards each other deliberately but unhurriedly. You eye the other person as you stroll, watching them grow as if out of the distance. The other person does the same to you.
The two of you finally get to the middle but bizarrely, do not meet. Instead, you go to left side of the street. The other person goes to the right side of the street. From this safe but baffling distance, the two you walk in a wide circle. Then you head into a nearby house while the other person wheels around and heads back in the direction from which he came.
Finally, pretend that the rest of us see this roundabout reunion only as a silent film. What should we make of it? What is the maritime counterpart?
Along a particularly narrow stretch of the salty snaky river of sea we call the Intracoastal Waterway, two groups of dolphins headed toward each other. They were both nursery groups, so-called because they only included moms and kids from a quarter mile away.
They have no idea that their narrow waterway was born of the same two forces that dictate their fortunes today, nature and mankind. Nature fashioned the barrier island that isolated the ICW from the Gulf of Mexico eons ago. But mankind started “fixing” it a hundred years ago. I have heard humanity called the naked ape. But I think a better nickname is the restless ape.
One nursery group was mother-calf pair Valiant and her little boy Vidalia. They were heading north. A quarter mile up the way, another nursery was heading south. It was a quartet of two female friends and another mother-calf pair, Front Slash and her tiny Fairuz.
Fairuz, which means turquoise in Arabic, was born last summer. Now it is entering the intoxicating phase we call Baby’s First Spring. At 9 months old, baby dolphins are deemed old enough (by mother) to play with a range of other dolphins, not just mom’s close associates. Sea school goes “viral” and such babies make the seas sparkle even more by their great enthusiastic animation.
Capt. John Heidemann and I have studied the adults in these groups for 10 years. One of the many curiosities of that effort is something we might describe as the Cashier Effect.
Consider how the cashier at your local grocery store sees the store’s clientele. She or he undoubtedly recognizes regular customers by face, maybe even by name. Yet those same customers do not know each other. This can be hard for the cashier to grasp: “What do you mean, they do not know each other?”
Between trying to get pictures of Fairuz, dashing around like any kid trying to get someone to play with it, I felt waves of the Cashier Effect. The two groups approached each other steadily but then did not really meet up. Instead, as in the above fable, they circled each other about 40 feet apart. Then Valiant and Vidalia went into a nearby cove to hunt.
The quartet reversed course and headed by from whence they came. What was this about? Why had they bothered? Maybe the real question is, why did they come that close together only to never touch?
When we first saw the dolphins, they were ahead in the distance. Both groups knew we were coming because the sound of our engine precedes us. It is as effective as an identifier as you phoning the person at the other end of the block and saying your name.
The dolphins can make trade communications – without the cell phone – by sending their signature whistles into the gloom to announce their presence and identity. Whatever else they may be communicating remains debatable.
But dolphins can vocalize to one another at distances far greater than the quarter mile between the nursery groups today. Unfortunately, we do not know if they were trading vocalizations (because the necessary sound-tracking equipment to hear dolphins when your boat engine is running is very expensive).
But let us assume that they were communicating. Let us say they were calling back and forth until they came close enough to see each other in the gloom of estuary waters. But no closer. Why did they not approach join into a single group, even for a moment? The calves did not play together. The moms did not swim side by side as companionable dolphins do. They simply came close for a moment and then continued on their separate ways.
There are plenty of people living near you who use the same resources that you use. But you do not know them. They do not know you. Ever think about how universal that is?
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.goodnaturedstatistics.com. NOAA advises anyone who sees a stranded dolphin in the Gulf of Mexico to call 877-942-5343 or 877-433-8299.