Monk Parakeet

The nominate subspecies of this parrot is 29 cm (11 in) long on average, with a 48-centimetre (19 in) wingspan, and weighs 95–120 g (3.4–4.2 oz). Females tend to be 5–10% smaller, but can only be reliably sexed by DNA or feather testing. Monk parakeets display very subtle sexual dimorphism in the colouration of their crown and wing coverts, but this is not noticeable to the human eye. It has bright-green upperparts. The forehead and breast are pale grey with darker scalloping and the rest of the underparts are very light-green to yellow. The remiges are dark blue, and the tail is long and tapering. The bill is orange. The call is a loud and throaty chape(-yee) or quak quaki quak-wi quarr, and screeches skveet. Domestic breeds in colours other than the natural plumage have been produced. These include birds with white, blue, and yellow in place of green. As such colouration provides less camouflage, feral birds are usually of wild-type green colouration, but other colours have been documented in the wild.

In its native range, the monk parakeet is very common. In Argentina, Brazil, and Uruguay, monk parakeets are regarded as major agricultural pests (as noted by Charles Darwin, among others). Their population explosion in South American rural areas seems to be associated with the expansion of eucalyptus forestry for paper pulp production, which offers the bird the opportunity to build protected nests in artificial forests where ecological competition from other species is limited.

The monk parakeet and the cliff parakeet are the only two parrot species outside some members of the African lovebirds (Agapornis sp.) that build nests. Monk and cliff parakeets are unique among even nesting parrots for their construction of large, external nests in trees or manmade structures instead of using tree cavities.

The monk parakeet is a gregarious species which often breeds colonially, building a single large nest with separate entrances for each pair. It is not uncommon, however, for pairs or individuals to nest outside of colonies, especially during the breeding season. In the wild, the colonies can become quite large, with pairs occupying separate "apartments" in composite nests that can reach the size of a small automobile. These nests can attract many other tenants, including some which cohabit with the monk parakeets. These tenants include many other birds, such as pigeons, sparrows, American kestrels, and yellow-billed teal, but mammals like red squirrels may also occupy a nest. Monk parakeets also sometimes breed in groups, with a Barcelona-based study finding that about 20% of monk parakeet breeding units are composed of three to five birds. …