These green parakeets have been building their large nests in 97 cities around Mexico.
These green parakeets have been building their large nests in 97 cities around Mexico. Pixabay/Public Domain

Mexico’s monk parakeet invasion began like most monk parakeet invasions. The small, green, South American bird escaped from somewhere in the pet supply chain. Over 20 years after they were first sighted in Mexico City, the monk parakeet population has exploded and expanded—the birds can now be found from Hermosillo in the north to Huajuapan in the south. According to a new study, this boom is the result of two specific policy changes, one in Europe and one in Mexico.

Monk parakeets are found in cities around the world thanks to the international pet trade, with notable populations in Brooklyn and Barcelona. The small, adaptable parrots may be an interesting and surprising sight, but they often end up building their large nests around heat-producing electrical infrastructure, which sometimes results in fires.

The monk parakeet's large nests can start fires when the birds build them on electrical infrastructure.
The monk parakeet’s large nests can start fires when the birds build them on electrical infrastructure. Bernard DUPONT/CC BY-SA 2.0

There was never much of a market for the pets in Mexico, but in 2005, the European Union banned all non-poultry bird imports, citing avian flu as a concern, a ban that was extended to all wild-caught bird imports in 2007. The following year, Mexico banned the purchase of native parrot species for pets. This opened both a market and a supply for the parakeets, and between 2008 and 2014 (when their import was banned in Mexico), close to half a million birds were brought in.

Those policy changes and the volume of imports track with monk parakeet sightings in cities around Mexico. The researchers compiled citizen science reports and scientific surveys from across the country for a 16-year period. The birds were first spotted in Puerto Vallarta in 1999. By 2008 they had only been spotted in five cities. By 2015, that number was 97. At the end of 2016, the Mexican government classified monk parakeets as an invasive species and resolved to develop a management plan. This study provides an important baseline for determining the next steps.