Bird flu is here to stay. NZ’s response must keep adapting as the virus takes hold

Dianne Brunton, Kristal Cain, Richard O'Rorke, University of Auckland, Waipapa Taumata Rau

The confirmation of Australia’s first mainland death of a mammal from bird flu last week highlights New Zealand’s challenge to manage the deadly H5N1 strain of the virus.

Bird flu has now been found in three wild birds in New Zealand, most recently in a northern giant petrel. Once established in wild birds, it cannot be contained or eradicated.

Like other emerging wildlife diseases, bird flu can change in ways that are difficult to predict. The challenge now is to remain vigilant in early detection, both in birds and marine mammals, and to adapt decisions and processes as new evidence emerges.

New Zealand’s response strategy takes a One Health approach, recognising connections between human, animal and environmental health.

The Ministry for Primary Industries coordinates the response, while the Department of Conservation focuses on threatened species and health agencies protect human health.

A vaccination programme of some of New Zealand’s most threatened native birds is underway, focused initially on five intensively managed species but with an ongoing review to include other species. New Zealand is also monitoring overseas vaccine trials for marine mammals such as the endangered Hawaiian monk seal.

Conservation scientists are applying “adaptive management”, which uses the best available evidence to guide decisions and adjust direction as new information emerges. The objective is to reduce uncertainty so that future decisions become progressively better informed.

This approach is already widely used in conservation, from managing North American waterfowl to protecting the Great Barrier Reef. In New Zealand, it helps prioritise actions in species recovery programmes, including for the most critically endangered birds such as the New Zealand fairy tern, tara iti.

When the threat keeps changing

Most early surveillance of bird flu internationally was on waterfowl, known reservoirs of these viruses.

But the current H5N1 outbreak caused unprecedented mortality among seabirds, including gannets, terns, gulls and skuas.

Then the threat changed again. In 2022, bird flu was detected in harbour and grey seals in North America and caused mass mortality in South American sea lions, with more than 30,000 dying in Peru and Chile.

It did not stop there. In 2023, an outbreak killed an estimated 17,000 southern elephant seals in Argentina. Genetic evidence showed transmission between marine mammals over thousands of kilometres and genetic changes in the virus associated with its adaptation to infect mammals.

The threat to marine mammals reached New Zealand’s region last year. In November 2025, bird flu was confirmed in marine mammals on Australia’s remote Heard Island, where surveys found that 13,000 of 17,000 southern elephant seal pups had died.

The progression of this disease from waterfowl to devastating seabird outbreaks, and then from sporadic infections in marine mammals to mass mortality and mammal-to-mammal transmission in South America, illustrates why management must adapt.

Adaptive management for bird flu

Imagine a surveillance programme where satellite imagery identifies wetlands likely to attract bird species with a higher risk of carrying bird flu, environmental genetic testing screens those wetlands for pathogens, and predictive models identify where surveillance should be concentrated next month rather than where it was needed last month.

Environmental DNA and RNA testing could help detect bird flu in environmental samples, while wildlife tracking and remote sensing could reveal where birds are moving and where risk is changing.

Predictive models could bring these different sources of information together to help decide where surveillance is needed most. The real value of these technologies lies in shortening the time between information collection and better management decisions.

New Zealand’s One Health approach already includes aspects of adaptive management. The Department of Conservation was preparing local response plans to a future bird flu outbreak and identifying high risk sites by July 2024.

A vaccination trial was completed in 2025. When H5N1 was detected in July 2026, the department deliberately kept the list of species considered for vaccination flexible so it could respond to emerging risks. These are key elements of adaptive management.

The opportunity now is to build on this work. One Health provides the framework for working together; adaptive management provides the opportunity for learning and improving as the outbreak unfolds.

Bird flu is understandably viewed as a serious threat to New Zealand’s wildlife. New Zealand is a world leader in protecting endangered species and preventing biological invasions. Bird flu now presents a challenge to become equally good at responding when prevention is no longer enough.

This article is republished from The Conversation under a Creative Commons license. Read the original article.