The Guardian

Scientists find that commercial hunting caused “basin-wide collapse” among aquatic species

Scientists estimate 4.5 million black caiman were commercially hunted in several Brazilian states between 1904 and 1969, making them the most popular aquatic or semiaquatic mammal.

Scientists estimate 4.5 million black caiman were commercially hunted in several Brazilian states between 1904 and 1969, making them the most popular aquatic or semiaquatic mammal. Photograph: BBC NHU/ Emma Napper

Scientists have conducted what they call the first systematic, historical account of the impacts on the Amazon basin of the 20th century international trade in furs and skins. The conclusion: “basin-wide population collapse” for aquatic species, but much greater resilience shown by terrestrial species.

The study focuses on four states in Brazil – Acre, Amazonas, Rondonia and Roraima – and draws on a wide range of historical records including those belonging to the Amazonas state government and the concession owner of the Manaus port. It was published in Science Advances in late 2016, but is reported now to mark UN World Wildlife Day. Here are 10 of the most fascinating – and sometimes horrifying – take-aways:

1 The numbers. Between 21.6 million and 26.8 million terrestrial, aquatic and semiaquatic mammals and reptiles from at least 20 species are estimated to have been commercially hunted from 1904 to 1969.

2 Top terrestrial mammals. The most commonly-hunted were collared peccaries, red brocket deer, white-lipped peccaries, ocelots, margays and jaguars. The number of jaguars killed was over 180,000 – a conservative estimate. All three species of cats were put on Appendix 1 of the Convention on International Trade in Endangered Species (CITES) in 1975.

White-lipped peccaries were the only terrestrial mammals to have “showed signs of population decline at both basin-wide and local scales.” This appears to be attributed to the fact that they range across large areas and travel in big herds which means they “can be slaughtered by the dozen”, especially when crossing rivers.

3 Top aquatic and semiaquatic mammals. The most commonly-hunted were black caiman, capybaras (“the world’s largest rodent”), giant otters, neotropical otters and manatees. The estimated number of black caiman killed was just under 4.5 million. All of these species, except the capybaras, were put on CITES Appendix 1.

4 US significance. Europe is flagged as one international export destination, but the most important was the US. Trade surged in the 1930s when the US “consolidated” itself as the “primary export market for Amazonian hides”, and then during the Second World War “nearly all” went there.

5 High fashion. Pelt prices sharply rose in the 1950s and 1960s following the “international fashion zeal for spotted felid furs”, leading to an uptake in commercial hunting. In an article published elsewhere, in Sapiens, one of the researchers, Glenn Shepard, from the Emílio Goeldi Museum in Belem, argues that this trend was partly driven by the 1966 Batman movie in which Catwoman, played by former Miss America Lee Meriwether, wore a jaguar-fur suit.

6 “Empty forest or empty river?” The scientists argue that their conclusions overturn previous assumptions that commercial hunting had led to an “empty forest” where terrestrial mammals had been devastated. If anything can be said to have been “empty”, they suggest, it was the rivers, not the forests.

7 Nowhere to hide. The reason terrestrial mammals were so “resilient” even when hunting pressures were most intense was because they could seek refuge in less accessible areas beyond the hunters’ range, the scientists argue, whereas the aquatic and semiaquatic mammals had no such option. The latter were even more vulnerable during severe droughts when they would have been forced into larger rivers more accessible to hunters. According to the scientists:

Rivers and floodplains were relatively densely populated and easily accessible to hunters. On the other hand, for most terrestrial species, forest interior areas provided refuges with reduced hunting pressure. When such refuges are sufficiently large, animal populations persist at large spatial scales regardless of the level of localized harvesting effort. . . During the mid-20th century, more than 80% of terrestrial habitat would have remained free of hunting, whereas more than 50% of aquatic habitat would have been accessible to hunters. We suggest that this was the main reason why large-bodied vertebrate populations generally persisted in the dense upland forests of terra firme, whereas they were nearly wiped out in the rivers and floodplains.

8 “Unclear” legal status of subsistence hunting. The scientists say that Brazil officially banned hunting in 1967 by passing the Faunal Protection Law, which “essentially criminalised all hunting and remains in force today.” This has created “serious legal barriers to the development of subsistence game management strategies for traditional peoples in the Brazilian Amazon”, although the scientists also say that subsistence hunting is “largely tolerated” in indigenous territories and extractive reserves because “human livelihoods [there] are protected by law.”

How serious a problem is this “unclear” legal status for indigenous and non-indigenous subsistence hunters? One of the researchers, Andre Antunes, told the Guardian that the 1967 law was not intended to “dogmatically” ban hunting because it still allows for permission to be granted according to “regional peculiarities”, yet he also says that the current Federal Public Prosecutor’s office has “adopted a stance of intolerance to subsistence hunting in conservation units.”

According to Antunes, from the Wildlife Conservation Society and National Institute of Amazonian Research in Manaus:

[The 1967 law has enabled Brazil’s government to deny] Amazon people’s rights to feed themselves through hunting, keeping them in criminality, in a permanent sense of fear and worst of all, assuming the possibility of them starving. . . The fact is that in a country where a poor hunter from the Amazon frontier can be punished for hunting an agouti to eat, a large landowner can deforest 80% of his land to plant soybeans.

Worse, Antunes says a bill was proposed in January this year that “seems to represent more of an outrage than an advance [on the 1967 law]. . . because it has clear intentions to spread commercial and sporting hunting in Brazil.” He says the government has got its priorities wrong: first, it should “guarantee the rights of traditional peoples” and then properly “regulate and institutionalise subsistence hunting, reshape management institutions, and monitor and analyse information.”

9 The future significance of their findings. The scientists argue that their research provides crucial historical context for understanding the Amazon basin and can help improve contemporary wildlife management and conservation practices going forward. They provide the example of a stretch of the River Iaco in Acre state where the decline of white-lipped peccaries in the 1990s had been previously explained by subsistence hunting, yet “our data show that these peccary populations had already collapsed in the mid-1940s.”

Such management must involve local people – and, in largely forested and/or protected areas, hunting represents more of an “opportunity” than a “threat.” “The most successful natural resource management programs in Amazonia have engaged local communities directly in community-based co-management,” they assert. “Involving traditional people is critical in wildlife conservation programs, given their inherent knowledge of natural systems and rapid management decision-making.”

10 “Empty forest” remains possible. The scientists acknowledge that the previously inaccessible basin-wide “refuge areas” into which the terrestrial mammals escaped are becoming increasingly more accessible to hunters. This is largely as a result of expanding agribusiness, cattle-ranching, roads and other infrastructure, and applies not only to Brazil but other Amazonian countries.

“If large refuges with limited road and river accessibility cannot be maintained, the combined effects of deforestation, habitat fragmentation, human colonization, wildfire, disease outbreaks, and hunting will likely result in the decimation of wildlife,” the scientists warn.