Two-year-old Ballou leaps out of a wake wave like a normal wild dolphin, catching up on playtime she missed during a sickly childhood.
Well, at least they came over and said hi before blowing us off completely. Capt. John Heidemann and I had arrived at the southern end of our study area, a quietly notorious bay for its general lack of dolphin sightings. What with the mackerel running offshore, there had been few dolphins in the estuary that day.
But conditions also made it hard to spot them. Utterly blue skies blending with peat-colored seas from recent rains created an unexpected (and unwelcome) camouflage for gray animals. Nonetheless, we spotted a small group of dolphins at the far end of the notorious bay and headed over.
Each of the five dolphins surfaced near the boat in turn. Two of them, Bet and her 2-year-old calf Ballou, surfaced a second time. Bet is particularly likely to greet the boat with a close encounter like this. I leaned over the gunwale eagerly to see how they were doing, especially Ballou, who had recovered from a particularly tough early childhood physically. But they did not surface again.
In the marvelous cooperation among wild dolphins, the quintet somehow communicated to one another that the plan was to duck underwater and zip to a little bridge as fast as they could without breathing. We next spied them in distant tea-colored waters, their vaporous exhalations creating gossamer columns against the dark shadows of the little bridge.
We needed to secure a few more photos for the federal record before they went under the little bridge and approached a little faster than normal. But as Capt. Heidemann skillfully applied what passes for boat brakes, Bet and Ballou launched over the water in the gesture dolphins use to ask to surf.
Consequently, instead of stopping, Capt. Heidemann swung past at modest speed. Indeed, Bet and Ballou vanished into our wake. They mostly surfed underwater upside-down, their gleaming bellies skyward. This was no simple surfing moment, though: It was the first time I have seen little Ballou surf! Considering that some dolphins outside your doorstep have surfed by the tender age of two weeks, it was good to see this undaunted 2-year-old catch up on lost time. Her leap in todayís picture was spectacularly reinforcing.
Then, as a team, Bet and Ballou leapt out of the wake together and headed back to their schoolmates.
As they left I thought, ďI have some bad news for you, Bet.Ē
The risks of living in nature have nothing to do with human superstitions. It was just coincidence that it was Friday the 13th, when that speeding boat zoomed over a local female bottlenose dolphin, Face, and her delightful yearling son, Facet, in a fatal encounter.
In the two weeks since that grizzly incident, Bet and Ballou were the only new dolphins to appear in the study area. Bottlenose dolphins are very intelligent in general, and our local dolphins have shown some startlingly profound timing at times.
YouTube videos of emotional reunions assure us that lions, gorillas and elephants have long-term memories of their friends, human and animal. I had to wonder if there was anything notable about the timing of Bet and Ballouís return.
There were lots of other good reasons to go into our database to see what kind of relationship Bet had with Face before she died.
One, when Bet was wounded by a shark in 2007, it was Face who accompanied her through the first tenuous days of her recovery. By doing so, Face may have put herself and yearling Babyface in danger. As such, Faceís behavior raised questions about the basis of the famous dolphin reputation for empathy for the injured and dying. For a species to get credit for empathy, that empathy must start by appearing in individuals. Face may have been one of those exceptional individuals.
Two, Face had been very friendly with Betís mom Tanks. That meant that when Bet was a baby at her motherís side, she saw Face often. After Tanks passed on in 2011, Bet and Face quadrupled their time together.
Three, in 2012, Betís calf Ballou was struck by a singular body condition that made her very sick for many months. When she was almost fully recovered, she still could not quite get away and a shark bit off part of her dorsal fin. During those months, Face and Bet doubled their time together. This year in 2013, before Friday the 13th, they were spending almost half of their time together.
How can I say that Bet and Face began to spend more time together than before? Data.
The technical scientific term for animal friendship is an association. Associations between animals are measured with the coefficient of association or COA. There are a couple of formulas for calculating COAs.
Generally, the coefficient is a ratio calculated by doubling the number of times a pair of animals was seen together and dividing it by the combined number of times they were seen at all. Mother-calf pairs have a COA of 1.00, indicating that they are together 100 percent of the time. COAs of .30 to .50 are often used to indicate true friendship.
I generated COAs for Face and Bet across the years of our study and found evidence of what we might call, in human terms, a growing friendship. Their COAs for the last two years are .35 and .45, respectively.
As Dolphin Watch has reported, Face had many associations. Bet mainly had Face.