A very occasional dolphin visitor to our local waters displays his fish handling abilities to get a local lady’s attention.
Do you know anyone with a photographic memory - those amazing annoying people who see something once and thereafter retain a flawless picture of it in mind?
True photographic memory may not exist. One test is to ask people to read lines of verse and then recite the words in reverse order, which they should do quickly if just “reading” the words backwards from a picture in their mind (brainfacts.org). So far, no one has managed. For most of us, memories are made of the most striking elements while the details get lost.
The dolphins that Capt. John Heidemann and I study for the federal government propose a new literal view of photographic memory: memory based on photographs. With phone cameras, people can and do take many pictures. If you review your pictures with any regularity, they reinforce your recollections of the frozen scene.
A recent dolphin sighting at sea reinforced my photographic memory and brought awesome implications with it.
The small cove had seven dolphins in it, widely spaced like people searching the woods, which seemed to fill it up. Three of them moved ahead of the rest. They were sized like the bears in Goldilocks’ story: a very large one, a middle-sized one and a small one.
The middle one and small one were mother-calf pair FM and her 4-year-old son Fennel, respectively. It took a while to get a good look at the big one.
The big one came upon a dazed sheepshead and began demonstrating his fish handling abilities, tossing and carrying the fish with a great show of arching and splashing. Dolphins act like this when “stylin” for another dolphin, which today was apparently FM.
Young Fennel crowded alongside the big dolphin, presumably watching closely. Given the bottlenose dolphin skill for imitation, Fennel may have been at sea school learning the big one’s technique.
When we finally got a good look at the big dolphin, I did not recognize it. We recognize individual dolphins by the unique pattern of notches on the trailing edge of their dorsal fin (the fin that appears when dolphins surface to breathe). Fins with characteristic patterns allow us to distinguish it from other dolphins and recognize its owner thereafter (as long as we review our pictures with regularity to reinforce our recollections of it).
But the big mysterious dolphin also had a lot of scars. Some were thin streaks down its flank. Others were ghoulish half-grins; some of these even dotted with individual tooth marks from the perpetrator. Others were thick wavy lines where a large long-ago gash had been inflicted. This big dolphin, whoever it was, had survived great dangers in its time.
As I scanned my memory banks of dorsal fin patterns, a picture of another dolphin with a lot of scars flashed onto the screen in my mind. At the time, it seemed like a non sequitur. It was a vivid shot from a summer evening just before sunset five years before: A dolphin was leaping nearly out of the water, which revealed its gruesome assortment of scars, with five bulls on its tail in mid-pounce. Because of all of its scars, I named it Bugsy.
But that was in 2009 and we have not seen Bugsy since.
When I returned home and inspected pictures of today’s big dolphin, I found a match with a picture I had taken in 2007. It was a fuzzy image of a dolphin, Bamboo, I had seen once. I was delighted. In the world of dolphin behavioral biology, matching a “new” dolphin to one already in the catalog is like getting a big check in the mail.
My memory of Bamboo’s unique dorsal fin pattern rested entirely on the single picture of it I had managed, with much effort, to obtain. Bamboo had been very hard to track. It moved wildly around the waters in the shadow of the Veteran’s Administration Hospital. When seeing dolphins behave this way, one cannot escape the impression that they are uncomfortable in our local waters because they seem to remain highly wary.
But today’s pictures of Bamboo were plentiful and detailed. I studied them carefully, especially those scars. It made sense to penetrate the archives for the pictures of Bugsy I had taken long ago that summer evening just before sunset.
The scars matched! The sunset picture was no non sequitur! Bamboo was Bugsy!
Bugsy has returned to our local waters! In doing so, he brings awesome implications with him.
His awesome implications are that, among the 313 dolphins we have identified to date, there is a group of very occasional visitor dolphins. These are dolphins we have seen just a handful of times over the years. But the awesome implication is they are consistent in their inconsistency, similar to the way I visit Chicago.
Bugsy is one of them. We have seen him only three times in seven years. Another is Hole, named for the gaping cavity bitten out in her dorsal fin, that we have seen only five times in nine years. Another is Honestly, named for the exclamation I made when I saw the gaping cavity in her dorsal fin; she has graced us with a baker’s dozen sightings in eight years.
The natural world out there, where we boat and water ski and drain the grime off our streets, is home to dolphins with specific patterns and habits. They do not move randomly or without purpose. Perhaps in exchange for their littoral version of photographic memory, we can do more to safeguard their humbling habits.
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.