Part 1: Where are the greatest Great Whale Gatherings?
Humpback Whale © Joshua Barton
If you were a documentary filmmaker wanting to film the greatest gatherings of great whales, where would you go? The same question might cross the mind of a scientist, a whale enthusiast planning a whale watching tour or a commercial wildlife tour operator planning a product expansion. In this article, I hope to provide some answers. What surprised me is that although much has been written about whales, very little has been written to pinpoint which species and where the greatest great whale gatherings take place. What is the equivalent in the oceans, of the annually recurring Elephant Gathering in Minneriya in Sri Lanka?
To share my conclusions up-front, it seems that of any great whale, the greatest recurring gathering is that of the Grey Whales nursing young in Laguna Ojo de Liebre in Mexico. Other whales which gather in large numbers, albeit unpredictably and often with little or no public access to ordinary tourists, include Antarctic Minke Whales in Eastern Antarctica. These aggregations are often driven by unpredictable super-blooms of krill. Only one toothed whale, the Sperm Whale makes it into the list of great whales. For the Sperm Whale, the greatest gatherings take place off Sri Lanka, but they are highly unpredictable unlike the gatherings of the Grey Whales. However, when the Sperm Whale super-pods are seen, they may make a stronger visual impression as large numbers move together. With the Grey Whales, they are spread out in a large lagoon and only a few at a time may be in the field of view.
Great whales for which there have been records of large gatherings include the Sperm Whale, Antarctic Minke Whale, Grey Whale, Humpback Whale and the Bowhead Whale. Although Blue Whales are not known in the literature for large aggregations, I mention the Blue Whales off Sri Lanka. Sperm Whales are the most social of the great whales. It seems that the famous Elephant Gathering in Sri Lanka is mirrored in the sea by a Sperm Whale Gathering where in a relatively concentrated area over 250 Sperm Whales may be seen. (More details on the Elephant Gathering are in the article ‘Branding Wildlife Brands: The Elephant Gathering’ published in the Daily FT (Sri Lanka) on 27th September 2012). However, the Sperm Whale Gathering lacks the same predictability of time and location as the Elephant Gathering and I would caution people against travelling to Sri Lanka in the expectation that their visits will coincide with one of these great gatherings. But Sri Lanka seems to offer one of the best chances to view or film a visually spectacular great gathering of great whales and it is special that a great whale gathering is within reach of the public, albeit subject to chance.
I focus on the ‘great whales’ as large gatherings by them attract public interest although large gatherings by the smaller species of dolphins are no less spectacular. The great whales were subject to ferocious hunting in the 19th and 20th centuries. We very nearly drove these sentient beings to extinction. The term ‘great whale’ encompasses the world’s 13 largest whales (or more, depending on taxonomic splits) including the Blue, Fin, Sei, Common and Antarctic Minke, Humpback, Grey, Bryde’s, and the 3 species of Right Whales (the North Atlantic, North Pacific and Southern), Bowhead and the Sperm Whale. The whales in scientific taxonomy belong to two groups, the baleen whales and the toothed whales. The former have sheets of baleen or whalebone suspended from the upper jaw, which they use to filter feed. Of the great whales, all but the Sperm Whale are baleen whales. In this article published in four parts, I will discuss some of the papers and observations, which relate to large aggregations of great whales.
My discussion on the baleen whales is relatively brief, as it seems that the Grey Whale is a clear winner and the other large aggregations of the other baleen whales have limitations with access, unpredictability or being too spread out to offer a visual spectacle of a mass of animals. I dwell at length on the Sperm Whale, long famed for large aggregations, but it seems not as much as the popular literature would have us believe. For ease of reference, I have broken this multi-part article into a section on baleen whales where I discuss a few species and a second section on toothed whales where I discuss just one species, the Sperm Whale.
Baleen Whales of the Northern Hemisphere
The largest great whale gathering I know of based on published data, since W.D. Boyer’s observation (more on this later in the second section on Sperm Whales) is from a paper by Steven Swart and others which refers to counts in the Laguna San Ignacio and in the Ojo de Liebre. In the Laguna San Ingacio they used a standard line transect method by travelling in a 7m outboard powered boat at a speed of 11km/hr. This is faster than the typical speed of the whales, which reduces the likelihood of the same whale being counted twice. The transect takes approximately three hours. In their paper titled ‘Numbers of Gray Whale (Estrichtus robustus) utilizing Laguna San Ignacio and Laguna Ojo de Liebre, Baja California Sur, Mexico during the winter breeding seasons:2007-2003’ they provide counts of adults and female-calf pairs combined, from 107 boat surveys between 2007 and 2013. The highest count was 320 on 26th February 2011, which comprised of 261 single adults and 59 mother-calf pairs. Thus if the calves were added as well the total count would have been 379. The lagoon is over 8km wide in places with the boat having visibility to 2.5km on either side and therefore these boat-based surveys are able to count the total number of whales in the lagoon with a reasonable chance of success.
But very importantly in the context of my article, their paper also includes the results of 12 surveys between January and April 2013 in the Laguna Ojo de Liebre, two of the three primary Grey Whale calving and breeding lagoons for the Grey Whales in the Eastern Pacific. The lagoon is 48km long and 9km wide. On 25th February 2013, they counted 137 single adults and 592 mother-calf pairs giving a count of 720. This would be 1,321 whales if calves were counted as an individual whale. They also include a table of data (provided by the Subsecretaria de Gestion Para La Proteccion Ambiental, Direccion General de Vida Silvestre, of Mexico) which summarises the highest counts between 2007 and 2013. In all of these years, the highest count of single adults and mother-calf pairs (treated as a single unit) were in excess of 500. The highest was on 5th March 2012 and comprised of 1,523 single adults and 1,198 mother- calf-pairs to give a count of 2,721. If the calves are added, this would be 4,919 individual Grey Whales. Such recurrent, large numbers of whales gathering seasonally is probably be the greatest recurring gathering of great whales in the world.
To the best of my knowledge, these counts exceed anything ever documented on large aggregations of great whales. Both locations are well known to local and international wildlife tour operators who lead tours to these famed nursery sites. Mark Carwardine, who leads tours to Laguna San Ignacio in a series of emails in May 2015 to me noted that ‘....several hundred is normal during the winter breeding season....’. It would seem to me that for scientists and whale watchers, in search of great whale aggregations, Grey Whales in the lagoons of San Ignacio and Ojo de Liebre may be the top choice in the world, subject to the caveat that the number of whales simultaneously in the field of view may not be as many as when a Sperm Whale super-pod numbering over 40 individuals is encountered. It surprises me that the local and international whale watching companies and local tourism authorities do not brand it as the ‘Greatest Gathering of Great Whales’.
Fin Whales are occasionally recorded in large aggregations. Elke Burkhardt and Caterina Lanfredi in their paper ‘Fall feeding aggregations of fin whales off Elephant Island (Antarctica)’ noted that on 17 and 21st March 2012, a group of more than 100 Fin Whales was observed during a study that comprised of 26 days of surveys. The mean group size was four although they observed larger group sizes of over 20. These aggregations were the result of large Antarctic krill swarms. Jorge Acevedo and others in a paper titled ‘Sighting of the fin whale in the Eastern Subtropical South Pacific: Potential Breeding Ground?’ reported that they had encountered a group that may have numbered over 100. The sighting was 1,517nm off the continental coast of Chile on the 30th May 2010. The previous large concentration of Fin Whales in the South Pacific was a group of 50 on 4th November 1958 reported by Robert Clarke in his paper ‘Whale Observations and whale marking off the coast of Chile in 1958 and from Ecuador towards and beyond the Galapagos Islands in 1959’. This sighting was estimated at ‘150 to 170 miles from shore’.
Humpback Whales are known to gather in feeding grounds and many whale watchers have seen groups in Alaska hunting using the famous bubble netting technique. However, the highest concentration recorded may not be in North America be in what Douglas P. Nowacek and others published in a paper titled ‘Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula’. In their paper published in April 2011, they reported on a super-aggregation of krill of the level which had been absent in the scientific literature for over 20 years. On 1st May 2009 they entered Wilhelmina Bay in the Western Antarctic Peninsula and recorded 149 sightings of 306 Humpback Whales in 65 km of line transect surveys with a density of 5.1 whales per square kilometre. They believe this density was the highest point estimate for Humpback Whales reported in the Antarctic. Whale watchers off British Columbia have reported encountering pods of Humpback Whales where individuals are all around them. However, at the time of writing I have not come across any technical papers, which suggest that more than a dozen are found in a pod.
Bowhead Whales have a population that occupies the Eastern Canadian Arctic and West Greenland. There is another population as well between the Chukchi Sea and the Beaufort Sea, which winters in the Bering Sea. Of the population mentioned first, Bowhead Whales are known to gather in large aggregations especially in Isabella Bay and Disko Bay in West Greenland. The Government of Canada’s website for the Ninginganiq National Wildlife Area (accessed in June 2015) states ‘...Up to 100 Bowheads have been recorded at one time in Isabella Bay, making this the single largest known concentration for this species anywhere in Canada’. K.J. Finley in his paper in 1990 titled ‘Isabella Bay, Baffin Island: an important historical and present-day concentration area for the endangered Bowhead Whale (Balaena mysitcetus) of the Eastern Canadian Arctic’ presented results that showed that 107 unique whales had been photographed between 28th -29th September 1996. The Bureau of Ocean Management published a study on 15th July 2013 titled “Bowhead feeding Ecology Study (BOWFEST) in the Western Beaufort Sea”. In their summary of aerial surveys, the highest count was on 18 flight hours logged between 29th August to 18th September 2009. They had 102 sightings of 452 Bowheads. During a five year study, 762 unique whales were identified from photographs.
The second population of Bowheads referred to above occurs seasonally in the area from the Chukchi Sea to the Beaufort Sea. Carin Ashjian and others in a paper titled ‘Climate Variability, Oceanography, Bowhead Whale Distribution and Inupiat Subsistence Whaling near Barrow, Alaska’ published in 2010 report on aerial surveys conducted in August and September in 2005 and 2006. They reported aggregations of Bowhead Whales of between 50-100 in early September of both years. Sue Moore and others in their paper titled ‘Bowhead Whales Along the Chukotka Coast in Autumn’ published in 1995 reported single day counts of 76 and 50 Bowheads on 1 October 1992 and 3 October 1993, respectively. S.W. Landino and others in 1994 published a paper titled ‘A Large Aggregation of Bowhead Whales (Balaena mysticeus) Feeding near Point Barrow, Alaska in Late October 1992’. On 19th October 1992, they observed 16 groups and 11 singletons, for a total of 104 whales over an area of 277 square kilometres. The largest single group contained at least 30 whales.
Continues the 5th of November...
Gehan de Silva Wijeyeratne
02 November, 2015