Collar parakeets grow to about 40 centimeters in length, with the tail accounting for roughly half of that. Weighing up to 140 grams, they are about as heavy as a blackbird. Adult male collared parakeets have a “collar” that starts out black on the front and transitions into a pink to orange-red stripe toward the nape of the neck. Juveniles and females lack this marking. The plumage of both sexes is predominantly bright green. When viewed from below, yellow-green hues dominate the plumage. The upper beak contrasts with the green plumage with a deep red hue.

The collared parakeet is a highly skilled flyer and a good climber. It uses its beak as a versatile, powerful tool. Parakeets feed primarily on plant matter and eat seeds, nuts, flowers, buds, and ripe fruit. When foraging, they may form groups. Their behavior in groups is particularly noticeable during flight to and from their roosting trees. Several hundred birds gather in roosting trees to protect themselves from predators at night. Collared parakeets maintain contact with others of their kind through soft and loud calls as well as loud shrieks.

Measuring 48 to 62 centimeters in length, the Alexandrine parakeet is considerably larger than the collared parakeet. A reliable distinguishing feature is the brownish-red shoulder patch found on adult Alexandrine parakeets. This patch is slightly less pronounced in females. 

The first open-air breeding of the collared parakeet was documented here as early as 1975. The first breeding pair of the Alexander's parakeet, which is also found in Wiesbaden today with significantly fewer individuals, followed in 1987.

The original home of the collared parakeet is Africa and southern Asia from India to Vietnam. They have been imported to Central Europe since ancient times and kept in private hands, menageries and zoos. Today's wild European collared parakeets are the descendants of captive refugees that have been released into the wild in several places since the late 1960s and have been able to settle permanently.

Collared parakeets have been observed and counted by volunteer ornithologists since 1975. Between 2019 and 2024, collared parakeets and Alexandrine parakeets were recorded as part of the Germany-wide parrot monitoring program by parrot expert Detlev Franz, bird conservation officer Oliver Weirich, and the Wiesbaden/Rheingau-Taunus District of the Hessian Society for Ornithology and Nature Conservation e. V. (HGON). This was done as the birds flew into their known communal roosting sites.

It is unclear to what extent an increase in the number of birds at the roosting site also indicates an increase in the number of parakeets breeding and foraging in Wiesbaden. Long-term data show that the number of parakeets at communal roosting sites rises every year until early to mid-July and then declines again. The explanation for this is that, starting in mid-July, some of the parakeets no longer spend the night at communal roosting sites but instead roost elsewhere, either alone or in small groups. The fluctuating count results from 2019 to 2024 can likely be explained in part by the fact that the ideal timing for the most complete count possible was not consistently achieved. While in 2019, roosting sites in the entire Rhine-Main region were known only in Wiesbaden, roosting sites in Frankfurt, Hattenheim, and Mainz have since been identified. Fluctuations in the number of individuals recorded in Wiesbaden are also likely related to the fact that parakeets move between these roosting sites. In particular, movements between Wiesbaden and Mainz are likely due to their proximity. Due to differing jurisdictions, the Mainz roost was surveyed only in 2020 and 2021 and has never been surveyed on the same day as the Wiesbaden roosts. In 2021, approximately 5,800 parakeets were counted in Mainz and Wiesbaden combined—about 1,000 more than in the record year of 2024 in Wiesbaden. The expansion of the collared parakeet population from Wiesbaden into other parts of the Rhine-Mainregion could indicate that, after 49 years of population growth, Wiesbaden has nearly reached its carrying capacity, and the number of individuals breeding and foraging here is no longer increasing as rapidly as before.

The fact that Wiesbaden has become the parakeet capital of the Rhine-Main region is partly due to the fact that they were released here in the 1970s and are loyal to their habitat. With its mild climate and the diverse, sometimes old and exotic tree population in the parks and cemeteries, Wiesbaden offers a good availability of food, roosting places and breeding cavities. German parks are very similar to the urban habitats preferred by parakeets in India in terms of the distribution of trees and the alternation of open areas and trees. There, too, they live in residential and inner-city areas.

The parakeets use all parts of the city that have suitable parks with old trees, cemeteries or suitable gardens. The best observation opportunities can be found in Biebrich Palace Park, the spa gardens and the rear spa facilities. For several decades, the parakeets have also been flying across the city and state borders, following daily flight routes from the roosting tree to the breeding territory, for example to Eltville, Ingelheim or Gustavsburg and back.

Some bird and wildlife conservationists view the spread of these non-native species with concern, as their establishment might, at first glance, lead to the displacement of native cavity-nesting birds such as woodpeckers, nuthatches, jackdaws, stock doves, or starlings, or of bats living in tree cavities. However, the data available to date do not indicate any harm to native animal populations in Germany. 

One argument against competition with woodpeckers, for example, is that the relevant woodpecker species—with the exception of the green woodpecker—generally create new cavities each year, and parakeets have already occupied their nesting cavities by that time. Male parakeets must present several cavities to the females, one of which they ultimately accept. In practice, this leaves about one-third of the cavities suitable for parakeets unoccupied.

Since parakeets feed primarily on plants, there is no competition for the severely depleted insect populations, which have significantly limited breeding success among many native bird species. The Federal Agency for Nature Conservation classifies the collared parakeet and the Alexandrine parakeet as non-native, potentially invasive species from a conservation perspective and lists them on the observation list; this means they are being specifically monitored to improve understanding of the impacts of their spread.

Thus, based on current knowledge, they are not considered invasive species in Germany, and no measures to control either species are currently necessary.

Parakeets reach a climatic limit in Germany. They can only be found where the growing season starts early. In regions that are too cold, there is not enough food available during the breeding season. As a result, parakeets have only been able to settle permanently in the warm river valleys of the Rhine, Main and Neckar. However, these climatic restrictions on their range will become less and less important as global warming progresses.

Settlements are almost exclusively in highly man-made habitats such as city parks, old cemeteries or old tree-rich gardens, in which tree species that do not originally occur here predominate. About half of the food plants of the collared parakeets are alien.

The beech and mixed beech forests around Wiesbaden, for example, are unsuitable for parakeets as they lack a year-round food supply. This also applies to the remnants of alluvial forest along the Rhine, which would be unsuitable for parakeets if they were not close to cultivated landscapes.

The food supply during the breeding season and the availability of nesting cavities are the most likely factors limiting the population density of parakeets in Central European cities. Natural hunters of parakeets are sparrowhawks, goshawks, peregrine falcons, tree falcons, large owls, martens and domestic cats. Parakeets are regularly found in the prey remains of peregrine falcons breeding on the Marktkirche. Other causes of death include pathogens and accidents. The loss of young birds after fledging, for example due to exhaustion, failure to re-fly after landing on the ground or broken wings, is also high among collared parakeets.

To date, there are no known health risks that can be transmitted from parakeets to humans. For example, the risk of free-ranging collared parakeets becoming infected with bird flu (avian influenza) and transmitting the virus to humans can be classified as low according to current knowledge. To date, no case of a collared parakeet infected with avian influenza is known.

Sometimes, collared parakeets nest not only in tree cavities but also in insulated house walls. In doing so, they typically use holes previously pecked into the insulation by great spotted woodpeckers. Damage to and within building facades can be mitigated independently through technical preventive measures (e.g., installing protective screens).

In Wiesbaden, it has been observed that the foliage on individual trees has been largely “nibbled away” by a group of parakeets. Healthy trees that show no other signs of deficiency generally compensate for the loss of leaves within the same growing season by producing new growth.

At the parakeets’ roosting trees, there may be complaints about their calls and the mess caused by their droppings. Disturbances caused by the parakeets’ calls are generally limited to the time when the birds arrive at their roost in the evening and depart in the morning. The droppings are mainly deposited in the morning before the birds leave the roost. In Wiesbaden, a large main roosting site for parakeets has established itself on Wilhelmstraße. Spreading the roosting activity across multiple sites would mean that far more people would be affected by the parakeets’ calls and droppings. Accordingly, it makes sense not to restrict the use of this roosting tree.

The Environmental Agency monitors the vitality of roosting trees that have been used over the long term in consultation with the responsible land manager. If significant damage to the trees is detected, measures to protect them can be initiated at an early stage. This would involve, for example, implementing local deterrent measures against the parakeets to protect the trees. Long-term vitality depends not least on the tree species and the concurrent effects of climate change.

With regard to parakeets, the legal regulations governing animal welfare, nature conservation, and species protection must always be observed. Pursuant to Section 39(1) of the Federal Nature Conservation Act (BNatSchG), it is prohibited to wilfully disturb wild animals, to kill them without reasonable cause, or to impair or destroy their habitats. For the Alexandrine parakeet, as a specially protected wild bird species, § 44(1)(1) of the BNatSchG also applies, which stipulates that it is prohibited to pursue, capture, injure, or kill animals of this species [...].

A guiding principle of nature conservation is that action should be taken against established invasive species (non-native species) only in cases of serious damage to the ecosystem. If negative impacts on native species are observed, an assessment is conducted to determine whether and what population management measures must be taken to counteract them. The Hessian Ministry for the Environment, Climate Protection, Agriculture, and Consumer Protection (HMUKLV) is responsible for this.

In areas where parakeets are present, thermally insulated facades should be plastered so smoothly that birds cannot climb them, or the facades should be covered with a protective layer. When dismantling scaffolding, the holes left by the scaffolding eyelets should be sealed so that they do not provide a foothold for parakeets. Heavy soiling of surfaces can be counteracted by more frequent cleaning.

If you intend to seal or remove a nesting cavity, be sure to contact the Environmental Protection Agency or the local nature conservation authority well in advance to ensure compliance with applicable laws and regulations.