A “Doomsday Virus” for Endangered Parrots?

Every time we test blood from new endangered parrot species with small, isolated wild populations, we find Psittacine Beak and Feather Disease (PBFD) virus, a particularly nasty airborne circovirus that destroys the skin and feathers while opening large, painful fissures in the beak that eventually breaks it apart. Cape parrots, black-cheeked lovebirds, Carnaby’s cockatoos, New Caledonian parakeets, Norfolk Island Green Parrot, red-fronted parakeets, swift parrot, orange-bellied parrot, and Echo parakeets are all endangered by catastrophic deforestation and/or widespread capture for the wild-caught bird trade, and ALL have high levels of PBFD virus in the wild population. Is this the “Doomsday Virus” for Endangered parrots?


Our research has demonstrated that PBFd is endemic to the wild Cape parrot population and thus should exist at low levels in the wild. Something has disturbed the balance… This poorly-known virus also attacks the immune system, opening the PBFD-positive parrot to bacterial infections like avian TB, Pseudomonassp., and pneumonia. The first to go are the down feathers, then the crown, breast, rump and eventually all body feathers disintegrate, leaving a naked parrot with just flight feathers. At this advanced stage the parrots are up to 50% under optimal body weight and die of exposure in temperate climates. The virus is airborne and highly-contagious, dispersing into the environment in the excessive feather dust caused by the disintegration of skin and feathers.


Parrots with PBFD have the appearance of being homeless and out of place. Forlorn and dejected by their circumstance more than their condition. It seems that, once a parrot population simply does not fit into their natural habitat anymore and have to abandon preferred food items, nesting trees and even habitat types, this malevolent virus slowly takes over until they cannot survive another day in the wild. The only solution is intervention at all levels with rehabilitation protocols for sick parrots and community-based habitat restoration projects. When beak and feather disease takes over it is time to take action and assist these intelligent birds in finding a new way of living sustainably in the wild again. Parrots are cultural animals that have highly advance vocal chords to support their complex languages of emotion, intention, attraction, information-sharing, kinship and ownership. They share information on food resources, vigilance for predators at feeding sites, safe roosts and breeding sites, as well as the companionship of, for the most part, a highly social bird taxon. African grey parrots have survived in captivity for over 85 years and have demonstrated advanced cognitive abilities by constructing sentences and developing a vocabulary. Most parrots are long-lived and mate for life, maintaining pair bonds through constant allo-preening and mutual affection.


We have been studying an outbreak of PBFD in a wild population of Cape parrots since 2008 and watched infection rates go up to 50% in 2011 and then a staggering 100% in 2011. This was due to a drought that resulted in a very low availability of suitable food resources. It was heart-breaking to follow panicked, sick and starving parrots searching for food. Soon they were turning up dead or unable to fly under trees, in swimming pools, and at clinics. We only managed to save four parrots in 2011 and one in 2012, and hope to do much better next year with more sick parrots expected in the future. We are currently raising funds to build a flight aviary in the Eastern Cape to house parrots during rehabilitation. Our research on PBFD in wild Cape parrots at the Percy FitzPatrick Institute of African Ornithology with the Department of Molecular and Cellular Biology (University of Cape Town) is the most in-depth study of the molecular systematics and activity of the PBFD virus ever undertaken. PhD student, Guy Regnard, has worked tirelessly to analyze and re-analyze all the samples as part of PhD thesis. We are now in a position to develop a vaccine specific to Cape parrots that could be used in the proposed re-introduction of a disease-free population in an area where they have gone locally extinct. We are also planting tens of thousands of indigenous trees in large indigenous fruit orchards or forest plots with local communities to provide alternative food resources within the next 10-15 years. Our project team has already erected over 200 Cape parrot nest boxes in Afromontane forest patches where suitable large hardwoods have been removed. Every year the Cape Parrot Project grows with new partnerships, new opportunities to stimulate positive change for Cape parrots in the wild, new members of the Cape Parrot Project Group, and more people involved. Please share this video and these links with your friends and become part of the revolution…


Rodnick Biljon
Cape parrots are only found in South Africa in areas with high mountains and old-growth Afromontane forest dominated by yellowwoods. There are less than 1,000 remaining in the wild. Please watch this important video about the Cape Parrot Project. (Rodnick Biljon)
Rodnick Biljon
Absolutely stunning portrait of a proud, wild Cape parrot sitting in a Cape lilac tree (often erroneous called a syringa tree). These yellow fruits are thought to be poison, but the parrots have been recorded eating them for over 50 years. (Rodnick Biljon)
Rodnick Biljon
Cape parrot taking off from a high perch. Caught here forever in this amazing photograph by the "Cape Parrot whisperer", Rodnick Biljon. (Rodnick Biljon)
Steve Boyes
Young male Cape parrot that tested positive for Pssitacine Beak and Feather Disease (PBFD) virus and more than likely died a few days later from bad cold weather and snow. (Steve Boyes)
Anja Joubert
Steve Boyes taking a blood sample from a Cape parrot in 2010. This research demonstrated that we were in the grips of a beak and feather disease epidemic that could threaten the local population. (Anja Joubert)
Steve Boyes
An adult female Cape parrot that was rescued after being found unable to fly in a swimming pool. She spent 3 months in a warm box on anti-biotics and supplements, and another 3 months in rehabilitation before being released back into the wild. She was to become known as "Alice". (Steve Boyes)
Steve Boyes
Cape parrot with advanced symptoms of Pssitacine Beak and Feather Disease (PBFD) infection. We tried to catch this poor guy, but failed. Nighttime temperatures went below freezing a few nights after this photograph was taken. There was not much chance of survival. We never found a carcass and never saw this youngster again... (Steve Boyes)


Great links for additional background information on Cape Parrot Project:






Please consider donating to the Cape Parrot Project via World Parrot Trust or Wild Bird Trust (Ref: CPP)… 100% of donations go to the Cape Parrot Project!!

Steve Boyes has dedicated his life to conserving Africa's wilderness areas and the species that depend upon them. After having worked as a camp manager and wilderness guide in the Okavango Delta and doing his PhD field work on the little-known Meyer's Parrot, Steve took up a position as a Centre of Excellence Postdoctoral Fellow at the Percy FitzPatrick Institute of African Ornithology. He has since been appointed the Scientific Director of the Wild Bird Trust and is a 2014 TED Fellow. His work takes him all over Africa, but his day-to-day activities are committed to South Africa's endemic and Critically Endangered Cape Parrot (Poicephalus robustus). Based in Hogsback Village in the Eastern Cape (South Africa), Steve runs the Cape Parrot Project, which aims to stimulate positive change for the species through high-quality research and community-based conservation action. When not in Hogsback, Steve can be found in the Okavango Delta where he explores remote areas of this wetland wilderness on "mokoros" or dug-out canoes to study endangered bird species in areas that are otherwise inaccessible. Steve is a 2013 National Geographic Emerging Explorer for his work in the Okavango Delta and on the Cape Parrot Project.
  • Linna

    A couple confusing things about this article: Are PBFD positive birds being reintroduced into the wild after rehab? If so, would not this actually promote the virus? And how is the potential vaccine being species specific? Is the finding that the disease is somewhat different among different parrot species?

  • Thanks for the comment, Linna. Rehabilitated PBFD-positive Cape parrots have been reintroduced into the wild. With 50-100% infection rates in a wild population of no more than 450 parrots makes it essential that we reintroduce individuals that have had the opportunity to fight the disease and possibly develop a tolerance. If infection rates go down significantly we will contemplate removing PBFD-positive parrots permanently from the wild. The vaccine still has to be developed and will be specific to Cape parrots. Its commercial feasibility is currently being assessed. Yes, the virus is significantly different between species and even between regions. Please let me know at steve@wildbirdtrust.com if you need any further info… All the best, Dr Steve Boyes (Percy FitzPatrick Institute of African Ornithology)

  • matt landos

    Hi Steve,
    Have you looked at the role of biomagnification of a range of immunosuppressive pollutnats in shifting the host-pathogen relationship?
    Very much in the thinking of Rachel Carson, there is growing evidence that things like pesticides, flame retardants and detergents are impacting on the endocrine and immunological health of all biota from fish, to reptiles and us. Do these birds ventture to orchards?
    All the best

  • Philippa Castle

    I run the annual Stanford Birding Photographic Competition in the Western Cape and with links at http://www.stanfordbirding.co.za I shall endeavour to do my best to raise funds for this very worthwhile project as well as increase awareness of their plight.

  • kathy

    I think your doing a great job taking care of these beautiful animals!! I wish I could so something like that!! When I saw what you did for those beautiful birds! Was so touched and got tears in my eyes!! Thank you so much!! Happy Holiday to everyone there!

  • Laurella Desborough

    I am very curious as to how this decision was made to release back into the wild ANY parrot with PBFD…with a small population at risk of extinction, it seems to me that IF there was an interest in preserving genes, that these PBFD positive birds would be set up in a research facility and MONITOR their health and to see what happens if they produce offspring…but releasing them back into the wild seems like an extremely hazardous decision in terms of preserving the species! If you are monitoring disease tolerance in a bird, how can you do that when the bird is in the wild. If it goes down, you will likely never find the body. If the bird goes down in a research facility, you WILL find the body! To me this looks like a big gamble.

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    I somewhat agree, but some matters should be done a bit differently.

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