International trade bans on endangered species tend to help mammals but hurt reptiles | Emory University
Bans on international trade in endangered species generally help mammals improve their status but hurt reptiles, according to a major economic study conducted by Emory University.
Science Advances has published the research on the impact of international trade bans by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
“We see large spikes in legal trade in anticipation of reptile species bans but not in anticipation of mammalian species bans, which could explain the differential effect of bans,” says Hugo Mialon, professor of economics at Emory University and lead author of the study.
The work is the largest study of its kind, spanning nearly four decades and including all mammal and reptile species for which threat level assessments are available from the International Union for Conservation of Nature (IUCN ).
Co-authors include economists Tilman Klumpp, University of Alberta, Canada; and Michael Williams, of Berkeley Research Group and Competition Economics LLC in Emeryville, California.
Their findings have important implications for policy makers. Since CITES does not operate in secret, increased trade activity in anticipation of impending trade bans is generally not avoidable.
“Anticipated peaks in trade can be particularly damaging when bans are applied to critically endangered species, as market prices for the few remaining specimens tend to be high, so eleventh-hour trade can be more intense and the recovery after the ban more difficult,” says Mialon. . “This suggests that trade bans should be implemented at lower levels of danger – in other words, when a species is near threatened rather than critically endangered.”
The authors offer several possible explanations for why the eleventh hour trade spikes did not occur – or were less pronounced – for mammalian species. One possibility is logistics, as many mammalian species in their dataset were many times larger and heavier than most reptilian species, requiring more effort to ship across international borders. Additionally, many species of reptiles, such as turtles and tortoises, are easier to catch than mammals. Finally, reptile species traded through the exotic pet trade are known to be less likely to survive physical relocation than mammals.
Mialon specializes in research on the frontiers between law and economics.
“From an early age, I was fascinated by wild animals and their importance to ecosystems,” he says. “The data available from IUCN on endangered species and CITES bans offered a chance to apply my expertise to potentially help save animal species from extinction. As far as I know, we are the first economists to tackle this subject.
Direct evidence of the effectiveness of trade bans imposed by CITES has not been conclusive. Several previous studies with small samples found that CITES regulations had a marginal effect, or no measurable effect, on endangerment.
Mialon and his colleagues took a more comprehensive approach to the issue. They focused on the period beginning in 1979, when data on CITES bans first became available, through 2018. Their analysis included the 41 species of mammals and 20 species of reptiles that received CITES bans during the study period and the thousands of species of mammals and reptiles that have been assessed by the IUCN during this period.
The status of a majority of species has deteriorated over the past four decades, due to various threats such as hunting, habitat loss and climate change. The statistical methods used by the researchers compared how the status of species that received CITES trade bans changed compared to those that did not receive bans.
Economic controls used in the study included data on GDP per capita, volume of international trade as a percentage of GDP, and population density, by country and year. For each species and year, the researchers averaged each of these variables over all countries in the species’ distribution, as recorded by the IUCN. They also constructed a measure of scientific interest in a species. And the analysis took into account factors that differ from species to species but do not change over time, such as the average adult size of a species.
The results indicate that, on average, trade bans work for mammals. A trade ban is associated with an average reduction in the likelihood of a species being considered endangered or worse, up to 17 percent, compared to species that have not been banned from trade.
Mammal species that eventually improved in status following a ban include the Guadalupe fur seal, gray wolf, northern bottlenose whale, ocelot, margay, sloth bear, the Samoan fruit bat, the Pacific fruit bat, Cuvier’s gazelle and the slender-horned gazelle.
“Cuvier’s gazelle and the slender-horned gazelle are clear examples of this,” says Mialon. “They were endangered in 2007 when they received a CITES ban and are ‘vulnerable’ and no longer ‘endangered’ today.”
However, the Dorcas gazelle, which has not received a CITES ban, was ‘vulnerable’ in 2007 and remains ‘vulnerable’ today, so it has seen no improvement in status.
“The three species are closely related, share a similar geographic distribution, and face overlapping threats,” says Mialon. “This provides an example of how trade bans work and may suggest that extending a trade ban to Dorcas gazelle could also be effective.”
In the case of reptiles, the analysis found that a ban on international trade is associated with an average increase in the likelihood of a species being considered endangered or worse by up to 42.6%, compared to species whose trade has not been banned.
Only American and saltwater crocodiles have seen their status improve following a CITES ban. Bolson’s Tortoise, Simony’s Lizard, Bog Tortoise, Kleinmann’s Tortoise, Antsingy’s Leaf Chameleon, Flat-tailed Tortoise, Spider Tortoise and Fathead Tortoise have all seen their status deteriorate following the ban.
One of the limitations of the study is that historical data on the use of other conservation measures in addition to CITES bans was not available, so it could not be used as a control variable. control. Another limitation is that the analysis only focused on international bans.
“Many endangered animal species are not traded in international markets but are still traded in local and national markets,” says Mialon.
Mialon and his colleagues are currently working on another paper on the effects of CITES international trade bans on plant species.
The research received support from Competition Economics LLC and the Social Sciences and Humanities Research Council of Canada.