mollwollfumble said:
I’ve read the research article, and still have no idea:
- Where they got their data.
- What gaps there are in the data sources, eg. Is the information dominated by western customs sources, by inspectors in SE Asia, by voluntary accounting by menageries, or pet shops.
- How much of the source data is antique, eg. More than 50 years old. Need a plot on the time axis.
Research articles have to say where they got their data.
Note the value of the trade in species quoted in the paper is not just for terrestrial vertibrates, it also includes plants.
Looks like i have to dig deeper.
“we searched the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the International Union for Conservation of Nature Red List of Threatened Species (IUCN Red List) databases to identify traded terrestrial vertebrate species (birds, mammals, amphibians, and squamate reptiles).”
Now reading https://trade.cites.org/cites_trade_guidelines/en-CITES_Trade_Database_Guide.pdf
it seems that the CITES database is well aware of the difficulty of the task. Where an animal is traded from one country to another, both import and export information is obtained and compared. Animal birth conditions are recorded eg. From the wild or from a registered breeder. Permits issued for trade are recorded. As are illegal seizures. And use is separated between live animals and animal products.
Limitations are inevitable – almost all examples are between one country amd another, not within a country. Some countries are very much sloppier in their reporting procedures than others. Since 1998 (and only since then) recorded species have been checked to ensure that authorities aren’t getting the species name wrong.
In other words, the database is as complete as possible, but misses a lot. That suggests that that 1 in five could be a gross underestimate. We can’t know for sure.