Elaine Henley tells us more about the Parrots of Stuttgart.
Elaine Henley P.G. Dip CABC
Full Member Association of Pet Behaviour Counsellors (APBC)
Animal Behaviour Training Council (ABTC) Registered Clinical Animal Behaviourist
Phone: 01294 833764
Due to factors such as globalisation and the pet trade, there are increasing numbers of non-native birds living outside their natural environment. The most well-known Parrot species is the Ringneck Parakeet (Psittacula krameri) which has been reported to reside in many rural and urban areas, in at least 27 countries. These individuals have not only adapted to a very different climate, diet, and challenging environment but they have thrived, successfully bred, and raised young to adulthood.
Larger species of Parrots were less likely to be found in urban jungles outside of their own native countries; that was until 1984, in Stuttgart, Germany when 2 Yellow Headed Amazons Parrots (A. oratrix) and 2 Blue-fronted Amazonian Parrots (A. aestiva) either escaped from their owners or were maliciously released into the wild.
There is a rumour that they may have escaped from the local zoo; however from only four founder birds, the population has grown to 50+ individuals who all call Stuttgart, home.
The Yellow-headed Amazons are native to Mexico and as there are less than 7000 individuals existing in the wild, they are considered endangered. The Blue-fronted Amazon is considered to be near threatened, and, in the wild they are found in the forests of South America.
Both these native environments are very different to Stuttgart. Although no one can know for certain, it is likely that one or more of the founding birds had been wild caught, as once they found themselves in the wilds of Stuttgart, they were able to adapt to find shelter, food, and tree cavities for breeding in.
So, what do we know about these incredible and resilient birds?
Although there has been some scientific interest in these birds, no one knows these birds better than photographer Bianca Hahn, a resident of Stuttgart who since 2016 has been following these birds daily and reporting her findings via her Facebook page:
Bianca knows every individual flock member by sight, recognising subtle differences in their colour markings. Another way of identifying them is by their claws, as many of them have lost a claw partly or in full due to frost bite in winter. Everyone has been given a name and assigned to a “family tree”; their success at raising chicks to fledglings noted.
Each morning at sunrise Bianca travels to where the birds have roosted for the evening and watches to see where they will begin their day. Following them, she can pictorially record what they eat, where they nest, their daily struggles with the environment and each other.
During breeding season, she concentrates her limited time to monitoring the nests and watching as the chicks fledge.
The Parrots have a range of around 5km and are rarely seen outside of this. They avoid forests with a dense tree population and spend their days in parks, allotments, cemeteries and planted courtyards.
What do they eat?
Bianca reports, and scientists have confirmed, that they will eat, walnuts, hazelnuts, maple, juniper, ivy, acorns, hornbeam, hawthorn, maple, yew lime as well as cultured and ornamental apples.
Certainly, there seems to be no shortage of food, even in winter. Although they prefer to eat when perched on a tree, they will also forage at ground level, when food is in short supply, or they opt for high fat nuts such as the Hazel nut.
There have been reports that some well-meaning locals have also been feeding recently fledged Parrots. Whilst this is understandable from a human perspective, it means that some of these birds have become too habituated to humans and by doing so, may be exposed to more dangers from flying into windows or have become too lazy to seek food for themselves.
As such, Bianca has taken in an Amazonian, who because she was fed continually by a human since fledging, has lost her skills to survive in the wild. Sadly, she will be a caged bird for the rest of her life.
Is predation an issue?
The Parrots’ only predators are the occasional hawks that come to the city. During the COVID-19 lockdowns, when there were less people around to scare the hawks away, the Stuttgart Amazonians suffered heavy losses to their population, with more than 10 being lost. Buzzards have been observed close to nesting cavities when the chicks have hatched.
Where do they breed and how successful are they?
Most of the preferred nesting sites are in local parks in an area called Bad Cannstatt. They favour cavities in large old London Plane trees (Platanus x acerifolia). The nests are found at least 50cm below the entrance; this design may offer some protection from the weather and predators.
Although there are hundreds of suitable trees in the parks, the Parrots will aggressively compete for access to fewer known and trusted cavities. I witnessed such a battle when I visited with Bianca, and she has photographed many more.
Parrot numbers increase very slowly; this may be attributed to cooler temperatures, a novel habitat, and a genetic bottleneck due to the low number of founder birds. Inbreeding is also causing serious deformities or non-viable chicks. Scientists in 2015 found that 50% of breeding pairs experienced nest failure; that is that no viable chicks were hatched and raised to fledging.
The female will incubate the eggs for 26 days, only coming out of the nesting hole twice a day to be fed by her partner. After hatching, the female remains in the nest for a few more weeks to feed and keep the chicks warm.
At this time their father will also begin to feed the chicks. Around 65 days from hatching the chicks will being to learn to fly and leave the nest. Although they begin to forage for themselves, they are fed by their parents for a further 3 months. After this they are rarely seen with their parents.
What are the main dangers that face the Parrots?
Data collected in 2015 shows that of 6 injured Parrots and of 15 who had died, collisions with vehicles (trams, cars) and windows were the main factors in injury and mortality. Not surprisingly, at the end of the breeding season in late summer and autumn, there is greater risk for newly fledged, inexperienced birds.
Bianca reports that ground foraging, particularly in the winter, exposes the Parrots to dangers from vehicles, cats, and dogs; that many injured and dead Amazons are found dead in streets planted with Hazel Trees.
How do they survive winter?
Surprisingly, Bianca reports that there are very few casualties lost to the winter. Their main roosting spots are in the trees on busy streets; here the buildings act as a windbreak, protecting the birds from the full force of snow, rain, and wind. When foraging during the day for food, they can be observed huddling together for warmth.
What do we know about their social behaviour?
During breeding season, established pairs will separate from the flock mate and raise their chicks together, whilst younger Parrots will hang out with each other. Once breeding season is over, Bianca has observed flocks of more than 20 hanging out together.
Most of the Parrots are monogamous and will only find another when their mate is injured or dies. However, their social lives can often be a bit of a soap opera with some individuals ditching their significant other and setting up a nest with another.
The Parrots display playful behaviour with each other, sparring and frolicking.
That 4 individuals could learn to survive within an alien environment, find shelter, food and to raise young, is nothing short of remarkable. We are all in the debt of Bianca for documenting their life stories, so that we can learn from them and use this knowledge to improve the lives of our captive Parrots.