NZ has spent years preparing for H5N1 bird flu. For some species, it may not be enough
With H5N1 now in New Zealand, protecting the most threatened birds will involve difficult decisions, careful prioritisation – and sometimes chance.
New Zealand has invested significant time and resources in preparing for the arrival of the H5N1 strain of bird flu, a highly pathogenic virus that poses a grave threat to the country's rare and vulnerable bird species. Despite these efforts, the preparations may not be sufficient to safeguard some of the nation's most endangered birds.
Many of these species inhabit small, isolated populations with limited genetic diversity, rendering them particularly susceptible to the ravages of disease. Genetic diversity acts as a natural safeguard against pathogens, allowing for a greater likelihood of survival and population recovery. However, in small, isolated populations, these odds are considerably diminished, sharply increasing the risk of extinction.
Although vaccines provide a crucial layer of protection, they are not infallible. A recent Department of Conservation-led trial involving five threatened species revealed that immunity wanes after three months, necessitating a third dose for maximum efficacy. The black stilt, or kakī, a critically endangered wading bird, serves as a prime example.
While the trial is now complete and New Zealand is actively vaccinating 300 individuals from these five species, the challenges of delivering this protection in the wild are immense. Catching and subsequently administering multiple doses to the same bird is a painstaking process fraught with uncertainty. Balancing the need to protect these species while also considering the resources at hand, conservation teams must make tough choices about where to focus their efforts.
On the Chatham Islands, a concerted effort is being made to vaccinate several threatened species, including the black robin, which inhabits a small population on Rēkohu/Wharekauri/Chatham Islands. In contrast, the larger population on nearby Hokoreoreoro/Rangatira may require a different approach, focusing on vaccinating as many birds as possible while managing the needs of other species.
Unfortunately, it is clear that not all birds will receive adequate protection in time. The varying levels of risk posed by H5N1 to different species, based on their nesting habits and social behaviors, further complicates the issue. Colonial nesting species, such as many seabirds, face a heightened risk due to close proximity during breeding, while solitary nesters like the kakī are more at risk during non-breeding periods when they gather in estuaries.
As the threat of H5N1 continues to loom, the situation remains fluid and uncertain, with continued surveillance and preparedness paramount.
Written by urgent.news from The Conversation AU's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
