Course:CONS200/2023/Impact of Invasive parakeets in Athens Greece and potential solutions

A flock of Monk parakeets (Myiopsitta monachus), identifiable by their green and gray 'scalloped' plumage.

Introduction

As globalization continues to provide further opportunities for invasive species to colonize new places, the parakeets in Athens Greece are unique relative to most others. They do not share the life history traits of many other invasives, such as the capacity for long-range dispersal. Monk parakeets are an invasive species scattered around various regions likely due to high propagule pressure. Contributing concerns about the threat that both the Monk parakeet (Myiopsitta monachus), and the Ring-necked parakeet (Psittacula krameri) pose to native species in Athens, they also cause considerable damage to plant species in urban and agricultural spaces. This page will explore information on both parakeets species, how they were introduced to Athens, their effects on the local ecosystems, and possible management solutions to these growing populations.

A Rose-ringed parakeet (Psittacula krameri) is commonly characterized by the 'rose ring' around their necks. The species is sexually dimorphic and only sexually mature males have this colorful ring.

Invasive Parakeets in Athens, Greece

Parakeets are a categorized as any small to medium-sized species of parrot. They are native to the a variety of ecosystems all around the world. Commonly spotted flying in large flocks, parakeets display some of the following characteristics:

• colorful feathers
• small to medium in size
• slender build
• long, tapering tail

Identifying characteristics of both species will help our understanding of the implications of the introduction of these species in Athens. By identifying their diets and behavioral characteristics, it is clear to see the various threats they may pose to the native species in Athens, Greece. There are numerous species of parakeets in Greece, domesticated and wild, though the two we will discuss are the Monk parakeet (Myiopsitta monachus) and the Rose-ringed parakeet (Psittacula krameri).

Monk Parakeet

The Monk parakeet (Myiopsitta monachus), which is also commonly called the 'quaker parrot' are native to many places around the world. Originating from Paraguay, Uruguay, Bolivia, southern Brazil, and northern Argentina, the monk parakeet has been globally distributed through the pet trade market. Although they are primarily found in urban habitats, their populations are expanding to rural areas to take advantage of food resources. The Monk parakeet is a highly adaptable species but prefers habitats in the wild such as open savannas, scrub forests, and palm groves. Because of this adaptability, they are considered invasive in 19 countries and are successful in foreign habitats due to behavioral and ecological traits including, flexible diets, sociable behavior, high tolerance to human disturbances, and high population growth rate. They have a strong preference for building nests in eucalyptus trees, and uniquely within parrot species, will create their own nests by weaving a variety of materials into a complex nesting structure. The physical geomorphology of the Monk parakeet is a medium sized body, on average 28-33cm in length, with green and gray feathers. The species is iteroparous, meaning they can reproduce multiple times, sometimes even within the span of a year. As forementioned, Monk parakeets are very sociable and it is common that multiple groups will habituate in the same nest in different chambers. They are unafraid of the presence of humans and will often stay in and around their nests if there is enough food available nearby. The diet of the Monk parakeet can be quite wide ranging from seeds, to leaf buds, blossoms, insects, thistles, cereal crops, citrus crops, legumes, and even sweet potatoes.

Rose-ringed Parakeet

The Rose-ringed parakeet (Psittacula krameri) is native to both Africa and Asia with an expansive range on both continents. The species has been widely introduced across the regions of Asia, Europe, the Middle East, Africa, North and South America, and the Caribbean Islands. Even where these species are native, they typically habituate urban environments where temperatures and food availability are more favorable. Depending on the quality of urban environments, they may favor agricultural fields for all the food availability. In less urbanized areas they persist in a variety of environments from deserts, savanna grasslands, wetlands and rainforests. The Rose-ringed parakeet can be described as a medium size bird with a green body and reddish colored beak. Their tail measures more than half of their body length which is on average 38cm. Rose-ringed parakeets are sexually dimorphic, the male juveniles of the species have a 'rose-ring' around their necks, which they acquire when sexually mature at the age of three. The females, adult and juvenile both, do not have the 'rose-ring' coloring around their necks. Juveniles of both genders require great care from their parents when they are young as they hatch fairly undeveloped. Sexually mature individuals are monogamous and breed seasonally, producing many young each year. The species generally has high reproductive success and an average lifespan of 34 years when domesticated.

Impacts on Athens, Greece

Biodiversity

Ecosystem

A nest built by Monk parakeets (Myiopsitta monachus) in which multiple groups may roost and habituate year-round.

Monk parakeets are described as both hostile and tolerant toward other terrestrial vertebrates, and much of their negative impacts come from outcompeting native species for resources. They oftentimes build large social nests that are complex structures from various materials in the nearby environment, and can be situated in less than ideal locations such as urban structures or small urban trees. Behavioral characteristics of the Rose-ringed parakeet, such as secondary cavity nesting, often creates conflicts with native species in the region. The Rose-ringed species has an estimated average home range of 751,000 m² which can contribute to the scale of their negative impacts on a local ecosystem.

Biological Implications

The growing parakeet population contributes to extinctions of native species in Athens, and increases the emergence of disease and transmission of pathogens . Invasive parakeets interacting with native wildlife also pose multiple risks to the immune-compromised such as young children, the elderly, the sickly, as well as domesticated animals, through the increased transmission of pathogens. For example, the Rose-ringed parakeet is commonly infected with a parasite called Sarcocystis falcatula. The infected individual may perish but can also pass the parasite along to other birds, reptiles, and mammals.

Agriculture

The feeding behaviors of the Monk parakeet can described as gluttonous, where they frequent local agricultural crops and cause significant degradation. Although the Monk parakeet is not the only species solely responsible for crop damage, their foraging enables opportunities for other species to participate in the damage who otherwise would not. The diet of the Rose-ringed parakeet is predominantly made up of seeds and grains, around 80 percent in total, which means there is high motivation for this species to habituate agricultural regions. The remaining 20 percent is mostly insects, plant nectar, and fruits.

Agro-economy

As climate change brings warmer seasonal temperatures, popular crops such as maize, pecan nuts, and sunflowers are becoming increasingly consumed by parakeet populations . Both parakeet species are known pests, and by damaging these crops, add pressure on the existing agro-economy in Athens .

Potential Remedial Action

Population Control

The government and scientific institutions alike have deemed forceful intervention necessary in managing the parakeet population and the imbalance they have caused to the local ecosystem . For example, in California the Monk parakeet is considered a pest, and are illegal to possess under any circumstances. Some methods that can be used to control and mitigate the issues posed by these invasive parakeets include nest removal, trapping and sterilization.

Nest removal: Parakeets commonly use "utility poles as a substrate for building large, bulky nests". As a result, their nest can have negative impacts on humans and the surrounding environment through the increased risk of fires and electric power outages. These "public safety risks and increasing liability and maintenance costs" make the suggestion of making efforts to remove their nests a viable solution for population control.

Trapping: Trapping is a population management practice that is often debated because of the ethical implications. It works by setting up traps to catch parakeets and then removes them from the area. Other criticisms of this method include how it is both labor-intensive and expensive, in addition to the ethical implications.

Sterilization: Sterilization is a method used to control the breeding of these parakeets. The process of sterilizations involves capturing the birds and sterilizing them so they can no longer reproduce. However it is important to note that this method requires significant amounts of resources and can be difficult to implement apart from on the small-scale.

Conclusion

Similarly to other places around the world, Athens is considering its options for management of the growing parakeet populations. The impacts of the parakeet species on the local ecosystem is significant, and with the seasonal changes brought on by climate change being favorable to the species, action is necessary. Some management options that are available, include public education on the risks of releasing domesticated parakeets, the removal of plant species that parakeets prefer to consume, and in the harshest of cases, culling the population through humane means.

References

Briceño, C., Sandoval-Rodríguez, A., Yévenes, K., Larraechea, M., Morgado, A., Chappuzeau, C., Muñoz, V., Dufflocq, P., & Olivares, F. (2019, November 5). Interactions between invasive monk parakeets (Myiopsitta monachus) and other bird species during nesting seasons in Santiago, Chile. Animals : an open access journal from MDPI. Retrieved February 15, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6912311/.

Castro, J., Sáez, C., & Molina-Morales, M. (2021). The monkparakeet (Myiopsitta Monachus) as a potential pest for agriculture in the Mediterranean Basin. Biological Invasions, 24(4), 895–903. https://doi.org/10.1007/s10530-021-02702-5.  

Luz, N. da. (2020). Undocumented birds: Echopolitics as interspecies resistance. Cadernos De Arte e Antropologia, (Vol. 10, No 1), 26–36. https://doi.org/10.4000/cadernosaa.3449.

Da Silva, A. G., Eberhard , J. R., Wright , T. F., Avery, M. L., & Rusello , M. A. (2010). Genetic evidence for high propagule pressure and long-distance dispersal in monk parakeet (Myiopsitta Monachus) invasive populations. Molecular Ecology, 19(16), 3336–3350. https://doi.org/10.1111/j.1365-294x.2010.04749.x.

Wang, L. 2001. "Myiopsitta monachus" (On-line), Animal Diversity Web. Accessed March 11, 2023 at https://animaldiversity.org/accounts/Myiopsitta_monachus/

Flory, A. 2019. "Psittacula krameri" (On-line), Animal Diversity Web. Accessed March 11, 2023 at https://animaldiversity.org/accounts/Psittacula_krameri/

Burgio, Kevin; Rubega, Margaret; Sustaita, Diego (September 30 2014). Kramer, Donald (ed.). "Nest-building behavior of Monk Parakeets and insights into potential mechanisms for reducing damage to utility poles". PMC PubMed Central.

Saavedra, Susana; Medina, Felix (September 1 2020). "Control of invasive ring-necked parakeet (Psittacula krameri) in an island Biosphere Reserve (La Palma, Canary Islands): combining methods and social engagement". Biological Invasions. 22: 3653–3667.

Pruett-Jones, Stephen; Newman, James; Avery, Micheal; Lindsay, James (February 2017). "Population Viability Analysis of Monk Parakeets in the United States and Examination of Alternative Management Strategies". Human-Wildlife Interactions. 1.

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