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.

BBC Wildlife Magazine - - CONTENTS - By Mark Carwardine

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).

Sin­gle smaller Antarc­tic minke whales have been seen to demon­strate friendly be­hav­iour. They are often spot­ted dur­ing Antarc­tic ex­pe­di­tion cruises.

Above: in­di­vid­ual south­ern right whales can be iden­ti­fied by their unique pat­terns of raised cal­losi­ties. Be­low: hump­back whale flip­pers can be up to 5m long and vary in col­oration across dif­fer­ent pop­u­la­tions.

Op­po­site page, top to bot­tom: the dive se­quence of a sperm whale; a sei whale mother and calf; the colos­sal blue whale can pro­duce a blow col­umn of at least 12m high.

Left: dor­sal fin vari­a­tions in the false killer whale. Be­low: re­vealed against a dark back­ground, these sei whale blows are eas­ily 10m tall. Bot­tom left: the un­der­side of a Per­rin’s beaked whale’s tail has a dis­tinc­tive star­burst pat­tern.

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