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BBC Wildlife Magazine - - Contents - SOURCE Na­ture Ecol­ogy & Evo­lu­tion LINK­

Anew sur­vey sug­gests that some whales and dol­phins have cul­tural and so­cial lives as rich and com­plex as those of pri­mates.

Bi­ol­o­gists have com­piled de­tails of the so­cial and cul­tural be­hav­iour of 90 species of whale and dol­phin, in­clud­ing re­gional song di­alects, in­di­vid­ual sig­na­ture whis­tles, co­op­er­a­tive hunt­ing and group de­fence and com­mu­nal rear­ing of young.

The sur­vey con­firms that in­creas­ing so­cial and cul­tural com­plex­ity has gone hand in hand with an in­crease in brain size, with large-brained species such as killer, sperm and hump­back whales dis­play­ing the most flex­i­ble be­hav­iours.

“The ap­par­ent co-evo­lu­tion of brains, so­cial struc­ture, and be­havioural rich­ness of ma­rine mam­mals pro­vides a unique and strik­ing par­al­lel to the large brains and hy­per­so­cial­ity of hu­mans and other pri­mates on land,” says Su­sanne Shultz of the Univer­sity of Manch­ester. “Un­for­tu­nately, they won’t ever mimic our great me­trop­o­lises and tech­nolo­gies be­cause they didn’t evolve op­pos­able thumbs.”

The gap be­tween hu­man and cetacean so­ci­ety is more than ma­te­rial, though. What about art, poetry, phi­los­o­phy and pol­i­tics?

“With­out a fully de­vel­oped lan­guage, which we as­sume they do not have, it is un­likely that they would have sym­bol­ism,” says Shultz. “So, dol­phins and rel­a­tives are far away from hu­mans, but they do have a cul­tural rich­ness not seen in most an­i­mal groups.

“Of course we don’t think they are equally so­phis­ti­cated,” Shultz adds. “What we do ar­gue is the so­cial or­gan­i­sa­tion com­bined with brain size evo­lu­tion lead to an in­crease in be­havioural ‘tool kits’.”

It is just such tool kits, say the bi­ol­o­gists, that have given killer whales the cul­tural and be­havioural flex­i­bil­ity to fill niches in widely dif­fer­ent habi­tats and con­di­tions from the poles to the trop­ics, adapt­ing their di­ets and hunt­ing strate­gies ac­cord­ingly and pass­ing them on as tra­di­tions.

Q. What do south­ern-right whales ( right) have in com­mon with bottlenose dol­phins ( left)? A. They both live com­plex lives. Q MA­RINE LIFE

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