Grey buildings, green birds

Native to the Indian subcontinent and the southern fringes of the Sahel, the ring-necked parakeet (Psittacula krameri) looks wonderfully out of place in the cities of Western Europe. How and when exactly the colourful bird species established itself in isolated pockets so far from its naturally occurring range is heavily disputed, and subject to many an urban legend. Some of the more entertaining stories include their release following the filming of 1951’s The African Queen, a pair being set free by none other than Jimi Hendrix in 1968 and the closing of a Brussels zoo resulting in the frustrated caretaker letting dozens of the animals fly into the ‘wild’ in 1974. A recent UK study tackling these theories instead suggested that the population was built on incidental escapes and releases – partially due to fears of the exotic birds transmitting diseases to their owners. 

Whatever the case may be, the ring-necked parakeet appears to be here to stay, with their numbers having increased dramatically in the last few decades. Key to this invasive success is their unusual thermoregulatory responses making the animals tolerant to lower temperatures, allowing their settlement in colder climates. They are most commonly found in urban gardens, parks or forests, being dependent on trunk cavities as nesting sites, but have also adapted to using buildings or utility poles for this purpose. A versatile, but mostly herbivorous, diet supports their venture into the urban space, as like many bird species they can take advantage of the additional human-supplied food sources. Furthermore, the parakeet is gradually prolonging its breeding season, and has been observed to be moving into more rural areas as well, suggesting that we will only see their distribution expand in the years to come.

Despite their charismatic appearance, it should not be forgotten that these parakeets are invasive, and could pose a threat to local communities by outcompeting native species. Birds that vye for the same nesting opportunities can be attacked and displaced by the ring-necked parakeet, a behaviour extending to some bats and even bees. The transmission of diseases to both animals and humans also remains a concern. Additionally, their spread to the countryside could be damaging to crop production, as the animals serve as a major agricultural pest in their native range, primarily feeding on corn and grain. Lastly, their distinct shrieks can cause noise pollution when the socially inclined birds gather in large flocks – something that can be annoying to people, especially considering the parakeets mostly appear in population dense areas, but can carry wider implications for native fauna relying on sound for communication or foraging.

Ultimately, more research is needed on the ring-necked parakeet as an alien invader, and it remains unclear if they are really harmful to their new home, and if so, to what extent. With both their population size and spatial distribution having grown rapidly, it is imperative to better understand their impact on local ecosystems to manage any complications that may arise. Conversely, their emergence in urban habitats half a world away is a testament to the resilience and adaptability of wild animals, and their presence could be a vibrant addition to city life.

References

Butler, C.J. 2003. Population biology of the introduced Rose-ringed Parakeet Psittacula  krameri in the UK. PhD thesis, Department of Zoology, Edward Grey Institute of Field Ornithology, University of Oxford. 

Ciprari, E., Ancillotto, L., Mori, E., Studer, V., & Chessa, C.. (2022). Rescue data as an alternative for assessing trends and phenological changes in two invasive parakeet species. Urban Ecosystems, 25(4), 1199–1206. https://doi.org/10.1007/s11252-022-01224-9

Heald, O. J. N. et al. (2020). Understanding the origins of the ring‐necked parakeet in the UK. Journal of zoology, 312 (1), s. 1–11. doi:10.1111/jzo.12753

Hernández-Brito, D., Carrete, M., Ibáñez, C., Juste, J., & Tella, J. L.. (2018). Nest-site competition and killing by invasive parakeets cause the decline of a threatened bat population. Royal Society Open Science, 5(5), 172477. https://doi.org/10.1098/rsos.172477

Menchetti, Mattia & Mori, Emiliano & Angelici, Francesco. (2016). Effects of the Recent World Invasion by Ring-Necked Parakeets Psittacula krameri. 10.1007/978-3-319-22246-2_12.

https://www.geograph.org.uk/photo/5231314

https://stats.sovon.nl/stats/soort/7120/?language=english

https://www.iucnredlist.org/species/22685441/132057695