Discovering whales
With 13 fresh species described in his game-changing new field study of whales, dolphins and porpoises, Mark Carwardine explains whale hunting of the scientific kind.
Mark Carwardine reveals the latest cetacean species to have sprung to light over the past 25 years
It’s an incredibly exciting time to be a cetologist – that is, someone who studies whales, dolphins and porpoises. These enigmatic marine mammals are mind-bogglingly difficult to study – they often live in remote areas far out to sea and spend most of their lives out of sight underwater – yet we now have access to space-age technology that, at last, is revealing some of their best-kept secrets. We still have an awful lot to learn but, in recent years, the new discoveries have been nothing short of remarkable.
The first real cetologist was probably the Greek philosopher and scientist Aristotle. He made a number of impressively accurate observations some 2,400 years ago – he differentiated between baleen and toothed whales, for example, and noted that dolphins give birth to live young. Over the centuries, others added snippets of information (mixed freely with wild guesses, assumptions and superstitions) but there was little concerted effort to understand much more. The science of cetology didn’t really take off until after World War II. Even then, most of our knowledge was gleaned from dead animals washed ashore, or killed by fishermen, and from some of the millions of whales slaughtered by commercial whalers. A few scientists also began to study captive bottlenose dolphins and other small cetaceans in concrete tanks.
But it was not until the 1960s that a few pioneer biologists began to study their lives under natural conditions, wild and free. In the days when modern technology had already taken us to the moon and beyond, we were just beginning to understand these extraordinary forms of intelligent life on our own planet. Indeed, at the time, the prospect of studying whales must have seemed about as difficult and challenging as exploring outer space.
Gradually, though, more and more people have become involved in whale research, and the number of projects and has increased exponentially.
Best of all, many of the informationgathering techniques have become increasingly sophisticated. Modern
whale researchers still study whales in the traditional sense, by simply watching them through binoculars – it will always be important to gather basic sightings data, such as date, time, location, group size, behaviour and so on. But, at the same time, they frequently enlist the help of state-of-theart equipment and the kind of enterprising and visionary research techniques that would make NASA proud.
Spot the difference
The modern whale researcher’s armoury consists of a variety of research techniques, beginning with something known as photoidentification. Biologists have been using unique and obvious natural markings to identify individual animals for a long time. Jane Goodall used facial patterns to recognise all the chimpanzees in her classic study in Gombe National Park, Tanzania, for example. It is an invaluable way of tracking associations with other animals over periods of days, weeks, months or even years. And, given time, it enables researchers to measure everything from calving intervals to life expectancy.
Whale and dolphin biologists are no exception. Some species have easily recognisable natural markings that are visible above the surface and make field identification relatively simple. Individual humpback whales are recognised by the unique black and white markings on the undersides of their tails, for instance, while right whales have raised patches of roughened skin, called callosities, which form distinctive patterns on their heads.
The differences can often be quite subtle, so each animal is photographed to confirm its identity and to provide a permanent record of its existence. This technique is known as ‘photo-identification’, or ‘photoID’, and has dramatically extended our knowledge of wild cetaceans in recent years. It is also an area of research in which amateur whale watchers can participate; it can be expensive, and time-consuming
Whale researchers frequently use the kind of enterprising and visionary techniques that would make NASA proud.
for professional researchers to spend long periods of time at sea, so they often rely on tourists to provide photographs for their catalogues. A great many of the photographs in the humpback whale and killer whale catalogues for the Antarctic, for example, have been taken by tourists on polar cruises.
As well as looking at whales’ outward attributes, scientists are keen to examine their ancestral history. Do different calves with the same mother share the same father? Are individuals that spend a lot of time together related? These and many other intriguing questions can be answered just by examining a tissue sample, such as a small piece of a whale’s sloughed skin. More accurately, it is the genetic material, or DNA, in the sample that is so revealing, because no two animals have exactly the same DNA (yet related animals show varying degrees of similarity). The clever detective work involved in interpreting this information is called ‘DNA fingerprinting’.
Keeping track
Much can also be learned by using technology to track marine mammals. It is possible to attach a specially designed tag to a whale, dolphin or porpoise, which gathers data and either records it for later retrieval (it has to be found – and recovered – in order to get the stored information) or transmits it to a special receiver. This is known as ‘telemetry’.
Some transmitters are merely tracking devices – providing little more information than the animal’s geographical position – but even these have filled enormous gaps in our knowledge over the years. However, more sophisticated models can provide information such as a whale’s swimming speed, the depth and angle of its dives, its skin temperature and the temperature of the surrounding water, its heart rate, any sounds it may produce, light levels, and much more besides.
The simplest form of transmitter – a radio transmitter – broadcasts a radio signal that can be received by an antenna in real time.
This is quite costly, though, as researchers have to follow the signal (and thus the whale) at sea, and the transmitter only works when it is above the surface (when the whale comes up to breathe) and, even under ideal conditions, is limited in range to line-of-sight.
A far more useful advance is the satellite transmitter. This beams signals up to orbiting satellites and from there back to receiving stations anywhere on Earth. The great advantages of a satellite transmitter are that there is no need for researchers to follow the whale in the field and it enables them to study individuals in the most remote parts of the world and most challenging conditions. Again, there are limitations: it only works when the whale surfaces to breathe, the signals are not in real time (they may be several hours old), and it requires a lot of energy.
With current battery technology, this can be quite limiting.
Whales, dolphins and porpoises live in a world that is dominated by sound, which they use to communicate, navigate and find food, and a great deal can be learned by listening to them underwater. This is an incredibly challenging area of research – it has been likened to trying to find out what goes on in New York by dangling a microphone from the top of the Empire State Building – but experienced whale scientists using sophisticated underwater microphones, called hydrophones, have been making some exciting discoveries in recent years.
Meanwhile, the advent of miniature video cameras, capable of recording in surprisingly low light conditions, is opening up a whole new world of cetology. Researchers are beginning to use these ‘crittercams’ to see what whales, dolphins and porpoises are doing underwater. Making observations like this is an area of research that land-based biologists studying terrestrial mammals have always taken for granted.
There are still no shortcuts in whale research. Studying such elusive creatures is all about being content with tiny snippets
of information that gradually build a more coherent picture over many years. It is like piecing together an enormously complicated jigsaw puzzle, where each piece brings with it new questions and unexpected surprises. The good news is that we have probably added more pieces in the past 10 or 20 years than ever before.
Age of discovery
It’s hard to believe, but some cetaceans have never been seen alive: Perrin’s beaked whale, for example, is known only from a handful of strandings in southern California. Others are still being discovered. When I wrote a field guide to whales, dolphins and porpoises 25 years ago, there were 79 recognised species. In my new Handbook of Whales, Dolphins and Porpoises there are 90 different species. The numbers are slightly complicated, because two species in the original guide have since been combined (the Indus river dolphin and Ganges river dolphin are currently considered to be one and the same – just the South Asian river dolphin) and two turned out to be a single species (the lesser beaked whale and so-called unidentified beaked whale are now known as the Peruvian beaked whale). Taking these changes into account, in just a quarter of a century, no fewer than 13 new species have been discovered.
But how do you go about identifying a new species and getting it officially recognised by the scientific world? Well, usually, it’s a long and time-consuming process.
First, you have to make sure that your discovery has never been described before. Then you designate what’s called the ‘holotype’ – a single specimen that shows the key features for the entire species (ideally, you should also designate a series of ‘paratypes’ – related specimens that show additional features, such as different colour patterns, or juveniles, or a female if the holotype is male). Next you have to write a formal description, including all the anatomical, genetic, behavioural and other features that mark it out as being unique and new.
And, at last, you have to come up with two new names: a unique scientific name and a common name, which, inevitably, will vary from language to language and region to region. This can be surprisingly difficult. I have had lengthy debates with beaked whale experts around the world about whether to call the smallest member of the beaked whale family the Peruvian beaked whale (its original name) or the pygmy beaked whale (a more recent, popular name). After many sleepless nights, I opted for Peruvian. But naming new species can be fun. A friend of mine once named a sea slug after his wife (she was not amused), while Carl Linnaeus, the 18th-century father of taxonomy, famously named an unpleasant-smelling weed after one of his enemies.
Once you’ve done all this groundwork, you have to publish it in a recognised, internationally accessible and (ideally) peerreviewed scientific journal. Then you keep all your fingers and toes crossed – sometimes for years – in the hope that your colleagues, and the powers that be, will agree with your proposal. In the world of whales, dolphins and porpoises, the ultimate arbiter is the Society for Marine Mammalogy, which, in turn, adheres to opinions and directions issued by the International Commission on Zoological Nomenclature.
If all goes well, and they do agree, then congratulations. You have officially named a new species.
MARK CARWARDINE is a renowned whale expert, conservationist and our regular columnist (see page 27).
Naming new species can be fun. A friend of mine once named a sea slug after his wife (she was not amused).