September 10 -- A humpback calf is at the surface, within an arm's length. Much to my delight, it flips up an adorable grayish fluke which, I note, is not only littler than that of its mother, but also much lighter in color and far less efficient.

An adult whale doesn't swim so much as it swells up out of the water. When it arches its massive back, the fluke follows effortlessly in one fluid motion that propels it forward and downward, leaving only a swirling slick on the sea. This calf has yet to achieve such elegance, wiggling as it pumps its tail at the surface.

We just finished a biopsy of this baby. It gave no reaction when the dart hit, although I winced just like I do whenever my own children get vaccinations. (An aside: Yvette quietly admitted to me that when she takes aim at a baby, she says, "I'm sorry" under her breath and repeats the apology when she pulls the trigger on the crossbow.)

Now the Gemini is circling to retrieve the dart with its plug of skin and blubber that will positively identify this baby in terms of gender, kin and population. The baby hangs around the boat. I am surprised and not a little concerned that mom is about 330 yards (300 meters) away, off cavorting with two other adult humpbacks instead of here with her offspring. Her calf seems extremely vulnerable.

Howard says he doesn't often see this kind of behavior in a breeding/calving area. Usually mothers and calves keep close together when they're here in Antongil Bay. Often a calf will swim right on top of its mother; when she surfaces to breathe, she pushes her calf up to do likewise.

Calves also spend a lot of time lolling at their mothers' bellies; two mammary glands, each with its own compressor muscle that squirts milk, are tucked inside the mother's ventral grooves. Sometimes they even breach simultaneously: Sue-the-intern was lucky enough to witness this phenomenon a couple of weeks ago. First the calf went airborne; then the mother and calf together. It was a moment she'll never forget, Sue says.

I can't take my eyes off of this calf, which at 12-feet-long (3.6 meters), is not even as big as its mother's fluke is wide. Howard and company have seen at least a dozen different mother/calf pairs this season, but this is a first for me. Likewise, I can be reasonably sure we're the first land animals this month-old mammal has ever encountered.

The calf, lifting its head above the water, seems intent to have a close-up look. Whether or not any whales in the wild become habituated is a topic of research, but surely this calf would not be; not here, and not yet.

Any cautionary instincts the calf has to watch us from afar, while under the protective flipper of its mother, seem overruled by curiosity about its environment. Maybe the calf gravitates towards us, suggests Howard, in the same way that crawling kids go toward the electrical outlets and plugs which are at their eye level.

Or perhaps the baby is trying to keep up with its speedier mother, but simply can't ; so it's attaching itself to our boat.

The problem with trying to analyze whale behavior, Howard says, is that there's usually an equally explainable alternative to however things may appear.

The calf, I notice, has a bloody patch in the center of its tail fluke. I'm worrying about the fitness of the mother and the welfare of her baby when the sea erupts in foam: a tail breach; then another -- right on its heels! With a swift contortion of her massive bulk, the mother twice twists her tail, flinging her lower torso out of the water before crashing down.

She seems angry. I hope it's not at us.

Howard assures me that the mother is acting in the best interest of her calf. Her pursuers are likely two amorous males from whom she's trying to escape. After all, her energy is being expended on her calf.

This mother likely conceived in these waters at this same time last year. She was pregnant for about 11 months, all during the roundtrip she made to feeding grounds in Antarctica. The fetal growth rate of baleen whales is the fastest of any mammal: about 20 times that of humans.

Every day this mother is producing up to 50 gallons of milk, which is 33 percent fat (human milk is 2 percent) -- all while fasting, no less. By the time she weans the calf, about 10 months from now, she'll have shed 10 tons, a full third of her body weight.

It makes sense that the males' strategy might be to get rid of the calf. Only then would the new mother go into heat.

At one point, the group comes together. The males manage to get in between mother and calf, positioning themselves on either side of the baby. Then they bang and splash about with their formidable white flippers, possibly wounding the calf.

The mother probably speeds up her swimming both to prevent the males from mating with her and to act as a decoy by leading these aggressive suitors far away from her calf. Whether or not she sees our motorboat as a baby sitter and hears it as a beacon by which she can return to her baby, that is anybody's guess, says Howard.

It would be interesting, he thinks, to drop a hydrophone in the water and listen. Are the mother and baby in some way communicating to each other during this drama? It's not something we can find out today. The sea is too rough for the sensitive recording equipment. Plus, we need to pursue the mother in order to biopsy her.

Howard aims to find out if mothers and calves are more likely to hang around in one part of the bay than another. Knowledge like this will come as a result of analyzing GPS data and then be used to inform future management plans here. The whale-watching guidelines that Howard and Yvette have thus far established for this area are the most stringent for any class of whale; for a mother and calf, non-research boats may watch for less than half an hour and must stay 400 meters away.

The pair will soon migrate together to the mother's feeding grounds, presumably in Antarctica. Whether or not yearlings come all the way back to the breeding area with their mothers is unknown. This baby, which won't be sexually mature until the age of 5, really has no compelling reason to show up here next year. At least none that we can think of.

But if it does, Howard wants to know it.

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