Bottlenose dolphin bulls communicate with each other in have many ways, ranging from affection to controlled and unrestrained aggression.
Despite his extraordinary riches, Kennedy said that a man’s success did not lie in the money he made but in the people around him, most importantly his family. If you’re lucky and loving, you have wealth in the relationships that make up your social circle.
But I wonder how much you noticed. We attentively watch our children and pets grow up, but otherwise, relationships just seem to happen before we realize it. Someone who was “just” your cousin or coworker before is now suddenly a good friend. Can we learn anything about the growth of friendship among the intelligent creatures out at sea?
Early this spring, a big burly bottlenose dolphin bull we’d never seen before appeared suddenly in our local waters and stayed around for some time. To honor his obvious physical power, Capt. John Heidemann called the strange new dolphin Xiphos.
Xiphos has stayed though the fall, which isn’t unusual because there have been some available females around too. What is unusual is that Xiphos might may be taking up with another big burly bull we call Schnoz, whose dorsal fin pattern resembles a nose in silhouette. If these two bruisers are striking up a friendship, it’s fascinating for several reasons.
First, that bulls of any type would “strike up a friendship” is intriguing because most male mammals views each other as rivals. But in fact, bottlenose dolphin bulls DO form strong, life-long bonds with one or more bulls.
Called “alliances” in the scientific literature and “bonded bull buddies” by Dolphin Watch, the attachment between bottlenose dolphin bulls is the strongest bonds that dolphins form; even the mother-calf bond is not as durable. But we don’t know much about it.
Second, about 20 percent of the 300 John’s Pass dolphins we’ve identified to date are mature bulls, and nearly all are part of an alliance or have cooperated in a super-alliance from time to time. Translated, male bonding is the norm out there among our local dolphins.
But there are exceptions, the most striking of which is Schnoz. We’ve watched him since 2003; that boy works alone.
Third, the opportunity to learn more about the process of male bonding takes intensive fieldwork because you need lots of time and money to study the few species that bond this way.
In addition to bottlenose dolphins, male bonding occurs among African lions. The brawny tawny pairs or trios of cats with magnificent manes trotting between African prides are lion brothers. Bottlenose dolphin bulls could be brothers but it’s unlikely; in any case, we don’t know. If Xiphos and Schnoz team up, it’d be great to sample their DNA.
How and why does the rare system of male bonding work?
As to why, animal behaviorists speculate that bonded males out-compete solo males and thus win [more often] in the game of love. As to how, we know almost nothing about how bond formation takes place. If Xiphos and Schnoz continue to appear together at sea, they’ll give us a glimpse.
Xiphos and Schnoz behaved similarly but independently across the warm months. Both appeared during the spring (typical bull behavior) and haunted the vicinity of females (also typical bull behavior for both lone and bonded bulls).
They used the same waters and often appeared alternately on our field surveys, perhaps monitoring each other in addition to the girls. Schnoz’ reputation is well established among local dolphins, but Xiphos may have had to establish his because he’s new in town. In any case, he took the time to soundly trounce a fish as a display for local bulls N and Rippington (who, by the way, we haven’t seen since!).
We know nothing about Xiphos - where he came from or how old he is. His dorsal fin has the roughened look that experienced bulls get as layer upon layer of old battle scars accumulate on their dorsal fins. Other than that, though, he’s not scarred up. He’s confident; he hunts under docks and only briefly hesitated about the research boat.
We know a lot about Schnoz. He’s unique. He’s big but nearly scar-free, though he periodically appears with the wounds of war with other dolphins. Scar-free males are either young or of high social status.
In nature, the high-ranking animals do not have to fight for their position; it is the low-ranking animals that must fight and become heavily scarred. Moreover, Schnoz’ dorsal fin is developing that roughed-up look from layers of old battle scars.
Nonetheless, he’s our local ladies’ man. He is so often in the company of a particular group of local lady dolphins that we’ve dubbed them the Schnoz Girls. Finally, Schnoz is unique in being the most conspicuously affectionate bull we’ve seen to date; whether this is related to his popularity with the Schnoz Girls is unknown.
By the start of fall, the two began to appear together in the same group with a number of local ladies who lost their calves this summer. I am intensely interested in knowing more about this process and will be keeping my eye on the bull.
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.dolphinsuperstore.com. Read her award-winning Dolphin Watch column weekly at www.TBNweekly.com. NOAA advises anyone who sees a stranded dolphin in the Gulf of Mexico to call 877-942-5343 or 877-433-8299.