The initially “unsaleable” breastplates, which the Tahitians believed were “charged” with the slain enemy's mana – the divine energy of his ancestors – after battles, suddenly became available for barter after Cook’s third landing in Tahiti in 1774. They soon became one of the most sought-after “South Sea curiosities” among Cook’s men for shipment to Europe.
In fact, the British now had something to offer for the purchase of a chest ornament that surpassed its spiritual value. They traded sacred red feathers of the Kula bird – the feathers in the color of the war god 'Oro, whose cult dominated Tahiti and the Society Islands at that time. These red feathers came from the Tonga archipelago, nearly 3,000 kilometers from Tahiti, where Cook and his crew were able to “bargain” for them in 1774 and 1777 before setting course for Tahiti.
At first, the British had no idea that these red feathers were worth their weight in gold in Tahiti. It was Cook’s Polynesian companion Mai, who sailed from the Society Islands via Tonga to London on Cook’s second circumnavigation and returned to his home island on Cook’s third expedition, who informed the British on Tongatapu in 1774. Thanks to him, Cook and his companions were able to use the red feathers from Tonga not only to buy ample provisions for their continued exploration of Tahiti and the Society Islands, but also to acquire exclusive cultural artifacts, which would otherwise never have found their way into a European museum.