The 'Wallace line' is the famous discovery resulting from Alfred Russel Wallace's painstaking travels through the Indonesian archipelago in the 1850s and 60s. This theoretical line designates the abrupt divide observed between the island faunas, one side hosting distinctively Asian animals and the other distinctively Australasian. Although Wallace knew little to nothing about the geology of the region, his ideas about the origin of the divide are aligned with our understanding of plate tectonics today. The snaking line matches the divide between two continuous land masses which were submerged at the start of the last interglacial period. As the ice caps melted and sea level rose, only the highest peaks of both continents were left as relics of the past. The striking difference in the assemblages of animal Wallace found on the islands is the result of 50 million years of independent evolution. Wallace is hailed as the father of biogeography, the study of the distribution of species and ecosystems in space and through geological time, yet is often forgotten as a key contributor to the theory of evolution by natural selection.
Although known as Darwinian evolution, the real key to unlocking the mystery of the origin of such a diversity and abundance of species was an essay Wallace wrote between bouts of delirium towards the end of his voyage in the Moluccas. Darwin was dumbfounded when he read Wallace's concise synopsis of the theory which he had diligently worked on for the better part of 20 years. As Tim Severin puts it in The Spice Islands Voyage, "Darwin was appalled. Here, in a few pages, was virtually the entire theory of evolution which he was gradually trying to hammer out. [...] Badly jolted by Wallace's letter, Darwin rushed into print. Working flat out on his long-delayed manuscript, Darwin completed it in only 17 months by producing a much shorter version of his original planned volume." The Origin of Species has been referred to since as "the book that shook the world" and evolution by natural selection is arguably the most fundamental scientific theory of the modern age. Few of us know and appreciate who Wallace was or what he achieved.
Aside from his brilliant scientific mind, Wallace was also one of the world's first professional naturalists. He financed his travels by sending back rare specimens to his agent in England, which museums or private collectors payed handsome sums to get their hands on. He dried the skins of exotic birds or preserved their skeletons, collected beetles and butterflies which he carefully pinned and annotated, once he even pickled the hides of five orang utans in arrack to send them to London. Without the revenue from these sales, Wallace could not have afforded the years of field work that shaped his theory on evolution. To him, the wild animals of the Moluccas, and particularly the tropical birds he discovered, were a source of economic profit.
In his book, Tim Severin describes his journey as he follows Wallace's trail through the Spice Islands, assessing the changes in the landscapes and wildlife over the last 150 years. Several passages comment on the contradiction between Wallace's awareness of the threat he was posing to these magical places by bringing them to the attention of westerners and his personal exploitation of the resources to finance his work. As Wallace himself wrote:
'It seems sad that on the one hand such exquisite creatures should live out their lives and exhibit their charm only in these wild inhospitable regions, doomed for ages yet to come to hopeless barbarism; while on the other hand, should civilised man ever reach these distant lands, and bring moral, intellectual and physical light into these recesses of these virgin forests, we may be sure he will so disturb the nicely-balanced relations of organic and inorganic nature as to cause the disappearance, and finally the extinction, of these very beings whose wonderful structure and beauty he alone is fitted to appreciate and enjoy.'
Wallace was right to be concerned, for only twenty years after his return, the European market exploded and at the peak of the fashion craze, was "importing 50,000 bird-skins a year to provide decorations for ladies' hats". In his environmental concern, Wallace was well ahead of his time. However, he was also a bird trader and relished the meat and eggs of certain rare bird species such as the maleo (Macrocephalon maleo). On Sulawesi, he set about tracking down the endemic bird, characterised by a blue helmet on the crown of its head, which probably serves as protection against sunstroke. His quest was a success: not only did the maleos' peculiar behaviour provide evidence for adaptive evolution, Wallace and his assistants killed 26, the skins of which would have fetched a good price in London. In this way, the young naturalist was an avant-garde conservationist but contradictory is his exploitation of rare animals and particularly birds for personal profit.
150 years after Wallace sent the first specimens back to Europe, Severin and his crew got a taste of the extent of the modern exotic bird trade in Indonesia. They met Haji Muslim Kadir, a bird trader "well known in Ternate central bazaar among the petty bird sellers who sold lories, parakeets and cockatoos directly to the public. [...] According to international agreement, the permitted trade in white cockatoos was a total of 1,000 birds every year from the whole of Indonesia. Yet Haji Kadir was sending that number every three months from one town, and had official permission to do so." Nowadays, virtually all towns and cities in Indonesia have bird markets and despite being a signatory to the Convention on International Trade in Endangered Species (CITES), illegal trade continues to flourish. A study in Sumatra (Shepherd, 2006) found that regulations and quotas for the legal trade of non-protected birds were not adhered to. Legally protected species were found openly displayed on market stalls, highlighting the lack of enforcement by the authorities. In fact the traders were well aware of the protected status and demanded a higher price for those species, unconcerned of legal consequences.
At the time of this study, 5 to 10 million birds were being captured in the wild every year worldwide, primarily for the commercial pet trade. Surprisingly, and with a 93% market share, Europe plays a central role in this trade. Australia halted imports of exotic birds in the late 1950s and the U.S. opted out of the market in the 1990s, leaving the E.U. to almost single-handedly drive demand. Such ruthless exploitation of exotic bird populations for pet owners in Europe hardly seems necessary, especially as the profits are often not destined for the producer (or trapper), rather enrich the importers, wholesalers and retailers on the European side. The exotic bird trade endangers the biodiversity Wallace treasured and was so adamant should be preserved, and though it made his invaluable field work possible, it is not alleviating human poverty today.
Sascha
