He was the first person to successfully export a large, viable shipment of Brazilian rubber seeds to the British Empire.

[4] His first book Rough Notes of a Journey Through The Wilderness from Trinidad to Pará, Brazil, by way of the Great Cateracts of the Orinoco, Atabapo, and Rio Negro, was published by W.H.J.

Thirty years after the fact, Wickham claimed in 1908 that he was responsible for stealing about 70,000 seeds[2] from the rubber-bearing tree, Hevea brasiliensis, in the Santarém area of Brazil in 1876.

[6] The Ayapua Boat Museum (Museo Barco Historicos) in Iquitos, Peru calls his actions "the greatest act of biopiracy in the 19th century, and maybe in history", citing that the seeds were never properly recorded on the ship's manifest and that the resulting plantations in Asia deflated the rubber boom in South America.

[7] He accompanied the seeds to the Royal Botanic Gardens,[8] from where seedlings were dispatched to British Ceylon (now Sri Lanka), British Malaya (now Peninsular Malaysia) and Singapore, (though the latter was not used for rubber), Africa, Batavia in Dutch East Indies (now Jakarta in Indonesia), and other tropical destinations, thus dooming the Amazon rubber boom.

In Brazil, Wickham is labeled as a "bio-pirate" for his role in smuggling the rubber seeds that broke the South American monopoly.