Friday, September 14, 2007

Dolphin getting some attention!

A female dolphin with a tiny calf attracts lots of female attention. When LA Stick appeared with her tiny newborn in late May, her 20 companions were mostly female although bulls BB, DD2 and N swung by briefly.

A female dolphin without a tiny calf attracts lots of male attention. Unhappily, LA Stick’s tiny calf was gone by June 22.Since then, there’ve been bulls around her: Big Nipple Square Bite, Cheetah, Dollop, Edge, Grin, KK, LA Cheetah, Midface, Rippington, Riptab, Square Bite Tall and Square Scoop. Oh, yes, and BB, DD2 and N.You never know about bulls.

Sometimes they fight around females. Other times, they do not. Over Labor Day, however, LA Stick and her cadre showed us a vivid new view of sex at sea. As far as we know, dolphins don’t have leaders. That is, they don’t have unquestionable leaders like the magnificent males who lead gorilla and Hamadryas baboon harems. But if someone follows you, you’re a leader. Dolphins have followers. Early morning, the rush of holiday boaters was starting.

The outgoing (ebb) tide exposed skirts of shoreline sand surrounding small islands. Just beyond the skirts, three little groups of dolphins streamed slowly across the shallows.LA Stick was in the lead, followed by five persistent bulls. Bulls Cheetah and LA Cheetah made the second group. Bull trio BB, DD2 and N made the third. Members of each bull group swam side by side and close together but the bull groups swam far apart.

Together they formed a triangle, LA Stick as the apex and bulls as the base.We weren’t monitoring vocalizations but from the surface, the bulls were orderly. An occasional shove or glint of fin suggested some underwater discussion. Otherwise, the shallow glide seemed steady as an elevator ride.However, the bulls were sharking: They swam so close under the water surface; their dorsal fins were continually visible.

Dolphins shark in very shallow water, when hunting and when socializing. Sharking is thrilling because it means something exciting will happen. The bulls’ sharking was more interesting because it implies minimal body movement. Elevators again rose to mind. In elevators, humans become reductionists, minimizing movement. In close quarters like an elevator, minimizing movement is understandable. Even innocent moves can be misinterpreted. They fanned across a deep channel, facing the current.

Each smoothly submerging and surfacing in the same spot, perhaps they fed on fish swept by on the current. Like their behavior, their fan formation was unexpectedly orderly as if it followed some rule about the allowable distance between dolphins in these conditions. Finished, LA Stick streamed back across the shallows. Like wedges, the sharking bulls followed. They passed sand bars of feasting shorebirds, where the orderly dispersion of egrets, herons, ibis and wood storks again expressed the ancient rule of reducing direct competition.

At a broad watery cul-de-sac where she often forages, LA Stick didn’t stop. That’s not to say she didn’t grab a quick bite. Coastal Keep Away was about to begin. She surfaced, an ashen pompano (Trachinotus carolinus) gleaming in her mouth. Normally, these tasty game fish have silvery sides. This poor chap was chalk white. We could see why. With bulls BB, DD2 and N on her heels, LA Stick started tossing the poor pompano like a kid bouncing a basketball while strolling with friends.

Only this time, the pompano was the basketball and they swam instead of walked.LA Stick’s version of bouncing a basketball was to submerge a short distance, rise and snap her head, shooting the pompano a couple of feet ahead. She lunged down and reclaimed the fish, water spattering off her sides. Repeatedly, she rose and punted the pompano, always to the right. It either wasn’t a game of Coastal Keep Away or she was real good at it because she punted without interference.

As such, pompano punting is an example of ‘respect for the possessor.’ Swiss ethologist Hans Kummer used the term to explain why capable Hamadryas baboon males left a [claimed] harem female alone. Captive and free-ranging dolphins show respect for the possessor when they leave other dolphins’ fish alone. To do this, you have to recognize the world from the other guy’s point of view.This fish tossing episode was more unusual. First, LA Stick was tailed by other dolphins. Fish tossers are usually alone.

Second, she punted repeatedly. Dolphins make quick work of tossing fish they intend to eat. Finally, the poor pompano seemed too big to eat. The picture revealing dolphin chew marks rather than severing bites suggested pompano punting wasn’t about breaking it into edible pieces. The cadre of bulls wasn’t her only audience. People crowded the sea walls to watch this rare reflection of dolphin social psychology parade by.

How did the dolphins view all this?Ironically, the Florida pompano’s scientific name means roughness. It was indeed one rough day for that understandably pasty pompano, maybe as rough as that final day for LA Stick’s little lost calf.Dr. Weaver studies wild dolphins under federal permit GA1088-1815, National Oceanic and Atmospheric Administration. Send her an e-mail at acweaver@tampabay.rr.com or visit www.dazzlingdolphins.com.

Quick "Facts about Dolphins"