Invasion of rose-ringed parakeet in South Africa ruffles feathers

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Colourful flocks of rose-ringed parakeets have dazzled people since they swooped into suburban gardens and parks more than 50 years ago.

But too few know that the tropical parakeet species, with their green plumage, red beaks and long arrow-like tails, are one of the world’s worst invasive parrot species, said Tinyiko Cavin Shivambu, an academic visitor at the University of Pretoria’s department of zoology and entomology. 

Endemic to parts of eastern and southern Asia and eastern to central Africa, 

rose-ringed parakeets have become invasive in 35 countries, including South Africa, and outcompete indigenous bird species for their food, nests and space.

Pet trade a main culprit

Rose-ringed parakeets were first introduced to South Africa in the 1900s as part of the pet trade. By the 1970s, Shivambu said that accidental escapes and intentional releases of caged birds saw their populations increase in Pretoria, Johannesburg, Durban and Cape Town. “People released them when they were tired of them, and now they’re causing problems outside.” 

Shivambu’s research for his PhD thesis focused on the population estimates, breeding and feeding biology of rose-ringed parakeets in the Greater Durban Metropolitan area.

These feral populations appear to be expanding, predominantly in suburban areas of KwaZulu-Natal and Gauteng.

“The population of rose-ringed parakeets in South Africa may continue to grow and spread to other urban areas if not controlled,” one of his studies warns.

Shivambu draws parallels with the rapid expansion of common myna in South Africa. “They used to be very little, but now after 50 to 70 years, look at where we are now with mynas. It’s going to be the same with the parakeets if we don’t do something.” 

Ruffling feathers 

In a citizen science survey, Shivambu asked 312 Durban residents whether control measures for rose-ringed parakeets should be supported. Most of the respondents said the birds should not be, with some saying mynas, house crows and starlings should be eradicated instead. 

Similarly, most of the respondents did not consider rose-ringed parakeets a pest while 64% provided feeding stations, which Shivambu said may sustain their population. Rose-ringed parakeets were reported to chase nine bird species, of which seven were native and two non-native. This means that they aggressively take over the nests of these other bird species.

Public perceptions may make managing the invasive species difficult, he said, adding that education and community outreach is important. 

“With the house crow, it was simple. People don’t care about them, so they just hired well-trained people to shoot them. But with parakeets, I don’t think we’ll win the war.”

Control measures include shooting the parakeets, which is not viable in densely populated areas, destroying their eggs and using mist nests. “You can’t use poison because you will kill bycatch,” Shivambu explained.

Taking over

Shivambu’s research notes how as secondary cavity-nesters, rose-ringed parakeets compete with native secondary hole-nesters. 

Nest displacement or destruction by rose-ringed parakeets has been documented in Europe, Israel and Venezuela, negatively affecting the breeding success of native birds.

“When I was sampling in KwaZulu-Natal, almost all the nest holes in white milkwood trees, which used to be used by our native birds,” he said. 

Globally, the rapid expansion of the breeding population of rose-ringed parakeets is considered a threat to the economy, agricultural production, biodiversity, human health and social life. 

The species is an agricultural pest and has been reported to be a reservoir of several transmittable bacterial and viral diseases. For example, the influenza virus H9N2 was isolated from pet rose-ringed parakeets imported from Pakistan to Japan between 1997 and 1998. 

‘People making money’

Brian van Wilgen, of the Centre for Invasion Biology at Stellenbosch University, said, “The problem with rose-necked parakeets is that there’s a whole section of our society that makes a living out of them — pet shops and that sort of thing, so, they’ve argued these things should not be banned.”

Shivambu agreed. “It costs R800 for one bird … The government is making money from issuing permits. How do you do that if you know that a species is causing problems yet you continue to issue permits for birds?” 

Urban specialists

It’s difficult to gauge what the long-term effect of the rose-ringed parakeets will be, said ornithologist Geoff Lockwood, who runs the Delta Environmental Centre in Johannesburg.

“We had a Spanish PhD student working in the park probably about six years ago. His specific research was looking at competition for nest holes. 

“What he found was that the only bird that could regularly stand its ground and have a chance of retaining its nests if the parakeets had their eye on it were the common mynas, which are also invasive and also alien.”

He said research showing rose-ringed parakeets outcompete other bird species is a common story throughout their range.

Real threat

Lockwood worries that because the parakeets are competing strongly with birds in urban landscapes, they could do the same in natural areas, too. 

“I don’t know if anyone has got a sense of how real that threat is. If they decide to intrude into the bushveld and so on, will they be able to find the foods they need, to survive the climate, and if they’re that effective at commandeering nest holes, the impact then becomes a real conservation concern.”

The trouble is that rose-ringed parakeets, while a little noisier and louder than most birds, are colourful and “still kind of unusual enough in some areas for it to be quite a nice surprise to see one if you don’t know the history”.

Watch: Feral rose-ringed parakeets in Johannesburg.