No one knows how much bottlenose dolphins express female choice for mates. But one December day, in the company of a young bull, local lady Slightwin gave the greatest aerobatic exposition I have seen by any dolphin anywhere in the world.
I know a handsome heterosexual who is 56 and never been married. He dates enthusiastically but has never taken the big leap. I do not have to point out how unusual he is.
Humans are passionate bonders. We console ourselves that love is as perennial as the grass but nonetheless develop very strong preferences for particular people. Yet when animals behave the same way, we simply say they are unsentimentally consorting temporarily or mate guarding.
Last month in heavy fog, Capt. John Heidemann and I were escorted at sea by three local bottlenose dolphins, bonded bull pair BB and DD2 and their current companion local lady Slightwin. They swam sleepily beside us as our research boat purred through the fog.
I love it when dolphins do that. It is rare. Our local dolphins are up and doing. They have no more time to drowsily escort boats than prolific people have to hang out.
The dolphins’ groggy nearness let me chip away at my unending curiosity about them. It added a layer of admiration on my view of dolphin echolocation, which continues to function flawlessly in weather conditions like fog that render the primary human sense of vision quite inadequate.
It also pointed out that big bull BB is escorting lady Slightwin. Like before.
One exquisite turquoise day this week, we saw the three of them again. They slowly cruised under a neat little bridge and commenced, in that curious dolphin way, to meander diagonally across a broad bay.
Midway, a tiny black body covered with white dots leapt spectacularly into their midst. It was Stick’s calf Twig, barely six months old. Stick hunted in the distance, her mothering skills unimproved. Her tiny Twig amuses itself as best it can, playing with floating flotsam and passing boats more often than do other calves its age. BB and DD2 know Stick well.
It is not normal for bottlenose babies to be black and covered with white dots (and we wish Stick’s little sprout the best of luck). But Twig is probably not contagious. Yet the BB trio ran away! Actually, their flight created an arrowhead pattern of waves, revealing that Slightwin sprinted away at top speed. The bulls followed her.
They sped into a distant cove. Slightwin loitered at its entrance, swam briefly around its interior, returned to the entrance and left.
Both bulls did what she did. But when there are two bulls around a female, one is usually the escort and the other stays peripheral to the pair. BB was the escort. He followed her more closely, allowing less space to grow between them. Periodically, though, he distanced himself to find food – a bull has to eat – and was sprinting after a snack when she left the cove. He hastily returned to her side.
BB has hovered around Slightwin like this twice before. It is more than simply staying with a fertile female. From fall 2010 through spring 2011, BB jockeyed between her, rebuffing the stiff rivalry provided by local bull N.
Dolphin Watch readers may remember the January 2011 story about dolphin behavior that resembled football; that was one of many fights over Slightwin. That time, Slightwin was definitely fertile and pregnant by June.
Dolphins are pregnant for a year. So the following spring of 2012, when BB swam with Slightwin for two months, she was heavily pregnant. If your job is being a wild bull evolutionarily selected to sow your seeds widely, why waste precious spring rite time escorting a pregnant female?
Slightwin’s June calf did not survive. She left the study area for six months, returning that December. BB was soon at her side but only briefly, either ousted by her succession of interested bulls or her choice. One of her choices might have been young bull PC.
I do not know if “she thought he was cute.” But in his charming company, she gave the greatest aerobatic exposition I have seen any dolphin do anywhere in the world. Interestingly, she gave her exposition in the very same cove she rushed into today.
The following spring of 2013 BB was again at her side, this time for four months. That was understandable. She was not pregnant. But that could have changed. And now that BB’s escort services are apparent again this spring of 2014, I really wonder.
Many moons ago, Dolphin Watch made the heretical suggestion that local dolphins may not live up to the species’ reputation of rampant promiscuity. After all, twice bull N has escorted local lady Split for months. Similarly, if we see lady Osiris, we see bull Midface. Bull Schnoz has escorted lady Split repeatedly. Now the pattern has surfaced between BB and Slightwin.
Consorting and mate guarding have to be worked out for bottlenose dolphins. But ultimately we may need different terms for that bull behavior out there, maybe like that handsome heterosexual who is 56 and never been married.
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.