Clueing up on Bermuda's whales
For two years, Bermudian author, columnist and photographer Andrew Stevenson has been totally focused on the making of his film about the humpback whales, and allied research of the project. Mr. Stevenson has also had the good fortune to receive positive identification of the underside of the flukes (tail fins) of five whales by Allied Whale at the College of the Atlantic through a match-up of his photographs with those in its archives of North Atlantic whales, of which there are thousands. In addition, some of his footage apparently alters some beliefs previously held by some marine biologists.
While the overall 'Humpback Whale Film and Research Project, Bermuda' still has a year to go to its projected completion, the photographer is pleased with his progress thus far. Now that this year's annual migration has finished and the footage is in the can, Mr. Stevenson provides this update on developments:
Feeding: "One question I had last year, which I think I have completely put to rest, is the fact that the whales are feeding here in March and April. I believe they are feeding not only on 'krill' and copepods and tiny fish and fish eggs, but also on small fish. Since starting the 'Humpback Whale Film and Research Project' in the Spring of 2007, observations I made during the first year are being reinforced by data made this year.
"Aspects of humpback whale behaviour I've observed put into question some of the basic suppositions I had heard before. For example, the North Atlantic humpback whales feed in the colder waters of the northern latitudes and not in their southern breeding/mating grounds, or during their migrations. It seems the North Atlantic humpback whales are not simply using the Bermuda seamount as a mid-ocean navigational waypoint or a resting stop, they are feeding here. Last year I photographed one whale for four days over a seven-day period. If they were migrating northwards, why stay a week in Bermuda? Indeed, whales are sometimes seen moving south-west along South Shore, contrary to their overall migratory route, which would be north.
"I have often observed whales diving consistently on the edge of Sally Tuckers and Challenger Banks. They will dive for seven to 20 minutes at a time, mostly staying in one area, although sometimes moving slowly along the edge, generally in water about 150-200 feet deep. This feeding behaviour increases as we get closer to the full moon.
"This year I managed to photograph a whale having a poop.! He had done a body breach where most of his body except his head is thrown out of the water. In the photograph you can clearly see the explosion of excrement from his anus."
Resident Whales? "We have seen whales consistently from December through January and February to the months of March and April. Is this because we have resident whales wintering here in Bermuda? According to archival records, whales did stay around Bermuda in the winter months. Whether these sightings are indeed a resident whale population, or an overlap of whales heading south and whales heading north, I don't know yet. Some whales don't arrive in the Caribbean until February, so it's entirely conceivable that a whale seen here in December and January could be a whale heading south still, although with their blubber store full, there would be no point hanging around here.
"I think it is entirely possible that the whales we see here in the winter months may be a resident pod. It would be great to get out on the water when these December/January whales are here and photograph their flukes, take a look at their sizes, photograph their dorsal fins and flukes, and make an educated guess as to their age and sex."
Singing: "This year I question whether the constant singing here is not related to mating, but rather pods getting together. There seems to be non-stop singing day and night, and we know that the whales up north maintain site fidelity, in other words go back to the same bays each summer. But down south where they mate and give birth it's a free for all with all the whales mixed up. About a quarter to a third of the whales have orca bite marks on their flukes, so we know the orcas must hunt the young calves, and it would make sense for the whales to get together into their family pods before running the gauntlet of orcas up north.
"I have noticed similar fluke patterns in some of the whales in a pod. Could this be an indication that they are indeed travelling north in family groups? Have they already formed into these units or are they forming up here in Bermuda? I have seen individual whales, pairs, triples and more milling around with constant whale song in the background and then suddenly there is a pod of seven to ten whales forming up in the late afternoon when they begin to move consistently along our South Shore as if they have formed a pod for the rest of the trip up north.
"Another observation is the white markings with pink 'sores' in the centre of the white scarring on the right hand lower jaw, no doubt from feeding. With some luck it might be possible to identify the flukes on these animals and match them consistently with IDs in the northern feeding grounds."
Mother and calves: "I have witnessed a calf of 15 months, fat as can be, with its emaciated mother, a clear indication that the calf is still feeding off its mother over the second winter in the breeding grounds down south. Most marine scientists believe the mothers abandon their calves after a year."
Mr. Stevenson will be discussing these and other findings during a special presentation at the Bermuda Underwater Exploration Institute on Wednesday, June 18, beginning at 6.30 p.m. sharp. Included will be two ten-minute videos, 'Sleeping with Whales', and 'Behind the Scenes on Close up and Personal', along with a high definition underwater video of a two-week-old humpback calf and its mother in the Dominican Republic. In addition, there will be footage of other mother-and-calf whales, also shot by himself, as well as photographs to illustrate some of the questions and answers. Tickets ($20) are obtainable from www.boxoffice.bm For full details of this event, and to learn much more about Mr. Stevenson's project see his website www.whalesbermuda.com