My final week in Tonga was at once exasperating and incredibly interesting. It was exasperating because the strong winds that have been around for much of the season continued, as did the swells, choppy conditions and murky underwater visibility.
It was interesting for several reasons: We ID-ed three more calfs, bringing the total to 16 for the season; We helped to reunite a calf and mother that had become separated from one another; and our final drop in the water was with a massive eight-whale heat run that had come to rest in relatively shallow water.
Winds of (No) Change
The winds were supposed to have settled down a bit last week, but that never happened. Instead, wind levels remained strong all week long. To make matters more difficult, the winds were fickle...coming from the north for a while, switching to easterlies, then a bit from the northwest, a few hours from the south, then back to the east, and so on.
The net effect of the temperamental, almost schizophrenic winds was swell coming from multiple directions, which produced whitecaps and choppy seas, leading to relatively murky conditions underwater. All-in-all, the prevailing conditions this year have been the most difficult ones I've experienced in Vava'u.
Besides just being a pain in the rear, the challenging conditions posed by the winds had several practical implications.
First, strong winds whisk away whale spouts, making them difficult to spot. As if that weren't problem enough, swells, whitecaps and choppy conditions resulting from the wind exacerbate the situation. Third, when you do spot whales, if the seas are too rough, it may be difficult or impossible to reach them, keep up with them, or get in the water (actually, getting out of the water is the tough part)...as the case may be. Finally, when you are able to find whales and get in with them, the visibility underwater tends to be rather cr*ppy, due to lots of teeny tiny air bubbles stirred into the water by the frothy conditions, which makes for a milky white cloud that makes everything look fuzzy.
But of course, if observing, photographing and studying whales were easy, what fun would it be?
During my final week for this season, we identified three more calfs (Jet, Fuli Fuli, and Chibi-chan), bringing the total to 16 for this season (plus a couple more we believe are additional calfs, but can't 100% confirm).
I'm putting together a PDF document summarising all the calfs we encountered, so instead of going into detail about these calfs here, I'll post the document to my blog soon.
A few weeks ago, a story came out in the mass media about a baby humpback whale in Australia that had somehow become separated from its mother (download 120KB pdf file). The little whale, which was found trying to suckle on boats, was but a few weeks old, and was no doubt hungry and confused. It eventually had to be put down, because there's no way for humans to nurse and raise a baby whale, and no one was able to locate the missing mother.
Last week, we experienced a similar situation, with a baby whale somehow getting separated from its mother. Fortunately in this instance, we succeeded in locating the mother and reuniting her with the calf. Here's what happened:
While we were following what appeared to be a heat run of three to five whales, we received a call from another boat in the area, asking for help to look for a female whale that had left its calf with the boat approximately an hour earlier.
In short, the boat was with the mother and calf during the morning. At some stage, male humpbacks approached the area, and the female seems to have left the baby to join the males. According to some of the people on the boat that I had a chance to speak with later, the mom spyhopped once as if taking a look at the boat, then swam off. Visibility underwater wasn't good, so I don't think anyone actually saw the precise moment the mom left.
When I heard the call for help, I contacted the boat and asked for a description of the whales. According to the captain, one of the males in particular had a unique pattern...a band of white that went far up the side of the body.
The heat run was moving rapidly, spending extended periods of time submerged, so it took some time until an opportunity to get into the water presented itself. Three whales (two others had peeled off and gone somewhere else by this point) surfaced nearby. When I dropped into the water, I got a clear view of the three whales...there was no mistaking the whale with the white band on its side.
I called over to the other boat and confirmed that I ID-ed the whale that the captain had described. The only problem was that he couldn't describe any unique features for the mom, so I couldn't ascertain whether one of the three whales I saw was the calf's wayward mother or not.
There weren't many options available at the time, so we decided to try to get the calf to follow one of the boats to the area where the three adult whales were cavorting. Problem is, the big whales had been travelling at high speed for quite some time (and were still doing so), which meant there was a lot of distance to cover. The complicate matters, the whales were heading out to open sea. With the wind and choppy conditions, we wouldn't be able to follow forever, as we'd get too far from land to be safe.
We enlisted the help of another boat in the area, and with a total of five boats helping out (one with the calf following it, four with the adult whales), we managed to keep track of the whales until the boat with the calf was able to catch up (probably took 30-45 minutes or so).
The real challenge, however, came when we tried to get the calf near the adults.
Adult whales, when they're engaged in a heat-run situation or something similar, tend to become preoccupied. They swim quickly, often haphazardly, and in many cases, they stay underwater for a long time...the net result being that it can be extremely difficult to predict when and where they'll surface.
Of course, as the cetacean version of Murphy's Law would dictate, the three whales in question were behaving precisely in this manner.
They dived and disappeared for extended periods, then surfaced a significant distance away. While it wasn't a problem getting the boats over to them before they dived again, it was an issue getting the calf over. Even though the calf had followed the boat diligently all the way from where it had been abandoned, it seemed oddly oblivious to the fact that its mother appeared to have abandoned it.
The calf seemed reasonably happy to tag along with the boat (at slow speed), breaching and playing as they moved.
So...big whales moving quickly, but little whale moving slowly while playing with boat = frustratingly difficult to put big whales and little whale together.
It took several tries, but when the big whales finally settled down a bit and started spending more time at the surface, we finally succeeded.
When the three adult whales stopped for a brief rest, the boat with the calf in tow approached within 15 metres or so. Soon thereafter, both the adults and the calf dived. Everyone on all five boats strained to make out any movement in the water, trying desperately to glean any bit of insight into what was happening below.
Several people on the boat that had led the calf to the area shrugged their shoulders and threw their arms in the air, signalling that they had no idea what was going on. Everyone fell silent. Time slowed, as if we were stuck in an ocean of molasses.
Then a slew of footprints appeared nearby in rapid succession, indicating that there was a lot of activity underwater. As I looked at the footprints, trying in vain to assign some meaning to them, the calf's tiny dorsal fin broke the water's surface, followed by a larger whale that surfaced alongside the calf.
The bigger whale snorted loudly and emphatically, in what I interpreted to be a sign of happiness, and the little whale and the bigger whale dived down in sync. Mom and baby were together again! Cheers and a round of applause arose from the boats, followed by an enormous sigh of relief.
The two other whales were still with the mom, and all the whales swam off together, still heading south and away from the islands, with one of the whale raising a pectoral fin, almost as if as waving goodbye.
Without another word, all the boats turned around and headed off in search of other whales.
Interpreting What Happened
I don't know if it will ever be possible for humans to understand what goes on in a humpback whale's mind, so I'm not sure if anyone can explain with any level of authority why the mother left the baby.
There are many possibilities to consider. Perhaps the mom accidentally left the baby behind, sort of like a mom and child getting separated in a shopping mall. Or perhaps the mom believed it safe to leave the baby in the "care" of the boat. Maybe the mom was indeed wayward and got distracted by the attention of several hunky males. It's also conceivable that the males forced the female away from the baby. Perhaps the presence of the boat and people affected the situation.
In addition to this incident and the recent story in the media about the baby whale in Australia, I've experienced this type of thing once before, in August 2005 in Tonga.
At that time, a female whale left her baby with my boat while she and an escort (male whale) disappeared for around an hour and a half. I think that particular baby was only hours old, as it was still wrinkly and seemed unable to control its movements. The baby was clearly hungry, as it tried to suckle on the boat (I have photos of the baby, but they're on film and not with me).
Fortunately, the mother and escort eventually returned from wherever they had gone to do whatever they were doing. As the adult whales swam casually by, the baby appeared to recognise them. It left the boat behind and joined them, then the trio swam off as if nothing had happened.
I also emailed a cetacean researcher friend in Hawaii and told him about my recent experience. Here's an excerpt from his reply:
"We've documented a number of lone calfs over the years, and of course they just had one in Australia. I've also observed two males separating a mom from calf. The calf frantically swam about our boat calling and calling. One of the males tried to wrap its pec fin around the mom and probe her with his penis. She would have none of it...and kicked him off but the males were relentless. Finally, mom managed to get away from the males and swoop up the baby. With the other lone calfs, we never saw the mom, just the baby who was trying to associate with anything including me (in water) and our boat. I was able to lead it to a group of whales but no mom was present in this group and unless it was this calf's mom, unlikely it would take on the calf or begin spontaneously lactating as has been documented in some odontocetes."
With these reference points in mind, I tend to believe that baby humpbacks getting separated from their mothers isn't too rare an occurrence, and that the attention of male whales is a primary consideration. This type of behaviour occurs in other animals. Males of some species of dolphins, for instance, forcibly separate mommy dolphins from babies in order to mate with the females. Male cats (domestic and wild) are known to kill babies that are not their own, again for the same purpose...mating.
In last week's incident, the female was definitely surrounded by males, and I can confirm from direct observation that at least one of the males was definitely sexually stimulated (i.e., horny).
It's difficult to know or even attempt to guess whether the mom and baby last week would have eventually found one another, or whether the baby would've died as a result of being abandoned. And while we were all ecstatic that our efforts to reunite the baby with its mom succeeded, there were still two excited males with the mom and baby when we left. It's possible that the males and mom left the baby behind again at some later stage, long after we'd gone.
Whatever the case may be, it was a fascinating and unforgettable experience.
Final Heat Run
And finally, as we headed back to port after swimming with mom and calf on our last day on the water, we came upon eight resting whales in shallow water.
Actually, it was a heat run that one of our other boats had been following for several hours. When I came upon them, the whales were taking a break. The water was about 20-25 metres deep, with a white-sand bottom.
The female (i.e., the center of attention) was lying on the bottom, while the males circled around and around her, coming and going, appearing and disappearing in the haze of the cloudy water.
Being near one whale is inspiring enough, but being in the midst of eight humongous whales is absolutely amazing! We swam among the whales for 20 minutes or so as the competitive males circled the female and surfaced from time to time for air, until the female finally left the bottom and started to swim again, with all the males in hot pursuit.
I couldn't have asked for a more perfect ending to our stay this season.
Six weeks is a long time. But surprisingly, six weeks in Tonga passed in a blink of an eye.
It'll take a long time to go through photos and piece together the various things we saw and learned during this season's stay, especially since I have to leave soon for my next trip.
Thanks for everyone who wrote to provide feedback, and I hope that my various ramblings in these blog posts have been interesting, perhaps even useful/ educational. And a really big thanks to all my friends in Tonga. See you next year!
I'm tidying up the calf summary this evening, so check back later for the PDF file.