Global bans on bird trade needed to stop invasions

Study shows that regional trade bans limits global avian invasion risk–but bans need to be global for full effect

GBIF-mediated data resources used : Occurrences of 14 bird species
Cacatua sulphurea
Yellow-crested Cockatoo (Cacatua sulphurea) by wklegend via iNaturalist. Photo licensed under CC BY-NC 4.0.

Wildlife trade can lead to species going extinct in their native ranges, but also to invasions in non-native habitats. Intended to protect endangered species, trade bans, however, may also limit the spread of invasive species, but the extent of this is unknown.

This study set out to assess how wildlife trade–and banning it–affects invasion risk globally. Using trade data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) database combined with avian invasion data including GBIF-mediated occurrences, researchers analyzed the global trade network and how it relates to the establishment of non-native species.

Not surprisingly, their analysis showed that countries that import more birds are more likely to be invaded. In the global network, a high number of import sources and a more central position also correlated with higher invasion risk.

In the European Union, the 2005 ban on importing wild birds reduced trade to about 10 per cent of pre-ban levels, and global avian invasion risk decreased–particularly in the EU. New trade routes, however, might overturn this development, suggesting a need for global bans.

Link to original article

Reino L, Figueira R, Beja P, Araújo MB, Capinha C and Strubbe D (2017) Networks of global bird invasion altered by regional trade ban. Science Advances. American Association for the Advancement of Science (AAAS) 3(11): e1700783. Available at: