Building a better picture of New Zealand poultry populations

Table of Contents

Why we need New Knowledge about Poultry Populations

If you have been following the poultry news from overseas over the last six months, you may have heard that the United Kingdom has been dealing with a large outbreak of highly pathogenic avian influenza (HPAI) in its national poultry flock since October 2021. The virus was first detected in swans at rescue sanctuary in England on October 27th and spread to at least four other backyard poultry flocks and one commercial turkey producer across the country within just 2 weeks. As of April 2022, more than 25 million birds have either died from the virus or been killed to help prevent further spread. This includes many people’s beloved backyard birds.

Situations like this always raise the question of whether anything could have been done differently to prevent such a devastating outbreak for both commercial and backyard poultry keepers. This outbreak has been particularly difficult to control because the virus also infects wild birds, which have likely been contributing to transmission between poultry operations with much higher risks for farms that provide their birds with outdoor access. Regardless, the collective years of experience that both veterinary and public health officials have with managing infectious disease outbreaks shows there are three key factors that influence the ultimate trajectory:

1. Early detection of disease incursions: The sooner we can identify the disease in sick animals, the sooner we can get control measures in place to prevent further spread between farms. This relies on individual farmers closely observing their animals for signs of disease and notifying either their veterinarian or the disease reporting hotline if there are any concerns.

2. Data on the demographics of animal populations: Once an outbreak has been detected, animal health authorities have very limited time to figure out which control strategies are likely to have the least impact on animal populations and their owners. The better the quality of data we have on the number, size, location, and historical contacts of animal populations, the better the recommendations we can make.

3. Strong collaboration between farmers, veterinarians, and animal health officials: Controlling infectious disease outbreaks is a team effort that requires everyone to play their part in limiting disease spread. Having clear, consistent messaging that reaches affected individuals in a timely manner and makes it easy for them to understand what they can do to help is absolutely essential.

We have seen these principles in action when the New Zealand poultry industry experienced an incursion of Infectious Bursal Disease (IBD) into a commercial egg farm in Otago in September 2019 and more recently following the detection of Salmonella enteriditis in October 2021. Thanks to regular testing, rapid response, and open communication, the commercial poultry industry has been able to get control measures in place to mitigate the impacts as much as possible. However, if a disease like Avian Influenza ever got into New Zealand, we would likely be telling a very different story because of the potential for backyard poultry to also be affected.

Backyard poultry populations remains a much greater mystery since there are no requirements for households with fewer than 100 birds to register ownership in a national database and there is also no national organisation that currently represents the interests of backyard poultry keepers. The only information we have comes from surveys like the 2020 Companion Animals New Zealand Annual Report, which estimated that ~6% of New Zealand’s 1.8 million household keep birds with the total population of backyard birds likely exceeding 500,000. An analysis of anonymised data from TradeMe® over the seven-year period from 01st January 2012 to 31st December 2018 showed there was a total of 137,270 recorded poultry trades between 59,225 unique traders registered on the TradeMe® website with birds being moved long distances across the country.

So how do we start building a better picture of this diverse and dynamic demographic of the national poultry flock?  That was the question we asked when first starting to plan the Poultry Intel project.  Check out the next article in this series for what backyard poultry keepers and veterinarians had to say about the current situation in New Zealand.


  1. Greening, S. S., et al. “Estimating the level of disease risk and biosecurity on commercial poultry farms in New Zealand.” New Zealand Veterinary Journal 68.5 (2020): 261-271.
  2. Greening, Sabrina S., et al. “Using multiple data sources to explore disease transmission risk between commercial poultry, backyard poultry, and wild birds in New Zealand.” Preventive Veterinary Medicine 190 (2021): 105327.