The Monk Parakeet (Myiopsitta monachus)

Monk parakeets have been living in the wild in Spain for many years since the 1970s and have thrived. Observations over the past few years indicate that the populations are increasing exponentially and the threats posed by the birds are relatively minor.

Monk parakeets are unique among parrots as they use sticks and twigs to construct bulky nests which can house multiple nesting chambers. They can build their nest virtually anywhere they can find a flat surface to begin construction. In Spain, trees are the most common substrates for nesting, preferring the tallest ones such as palms, cedars, pines, eucalypts and planes trees. Parakeets in the United States build nests principally on man-made structures, such as stadium light poles and electric utility facilities, resulting in an ongoing maintenance problem for utility companies. 

Monk parakeet does not compete with other species for nesting sites (unlike the Rose-ringed parakeet) and actually share their large communal nests with a variety of creatures and have been known to share with diverse avian species in their native South American range (e. g. Lark-like brushrunner, Spot-winged falconet and Yellow-billed teal) as well as House sparrow, Spotless starling, Western jackdaw, Little owl, Common kestrel, Common wood pigeon and Rock dove here in Spain, helping to support these species.

Monk parakeets are mainly grass seed eaters and there is no evidence that they compete with native birds for natural food sources. Although they may cause any substantial agricultural damage, they do not venture many miles into the countryside, preferring to remain in urban areas and forage for food within the nesting range.

According to Bucher and Aramburú (2014) the invasive potential of monk parakeet and other parrots appears to be related to behavioural flexibility and dietary opportunism favoured by high intelligence and morphological adaptations (beak and foot structure).