What does H5 bird flu mean for your local birds?

Part 1 of Bird Flu and your Local Birds: A short, practical series for people who love the birds around them.

• Read Part 2 – Bird flu: what to do in your garden and local patch
• Read Part 3 – The long game: building healthy bird populations

If you love the birds in your garden, the question you’re probably sitting with is some simple ones: what does bird flu actually mean for them, and is there anything you can do to help?

This blog series will help you understand what’s happening and, just as importantly, show you that there are real and meaningful actions you can take, right where you live. 

Before we get to what you can do, it helps to understand what H5 is and why it matters so much here. It’s been devastating wild bird populations overseas for years, and now that it’s arrived, the first thing to know is that not every bird faces the same danger. This piece sets out what’s happening and which birds are most at risk including the reassuring news that the small birds most of us watch in the garden sit at the lower end. 

When H5 bird flu spreads through populations the effects can be devastating. During outbreaks in the UK breeding colonies of affected birds such as terns or gannets were reduced by a third or even half – a nightmare for a slow breeding, long-lived species. And for highly threatened species battling multiple level threats, H5 bird flu may have serious implications for the species persistence. 

So which birds are most at risk?  

It comes down to two things: how likely a bird is to catch the virus in the first place, and how well it copes once it does.  

Bird flu spreads most easily where birds gather in big numbers, especially around water, and among birds that eat other birds. H5 bird flu can be transferred between birds through saliva, droppings, blood and other bodily fluids, and contaminated water provides more opportunities for this to occur.  That puts the waterbirds of our lakes and wetlands, like gulls and ibis, the seabirds and the raptors most at risk. Added to this is the fact that H5 bird flu has never been present in Australia till now – so our Australian birdlife is especially vulnerable. This is because our continent is somewhat isolated from the rest of the world, so our birds have had less exposure to similar viruses and are less immune as a result. 

The birds most of us watch in the garden – the fairy-wrens, honeyeaters and magpies, are at lower risk, because they don’t crowd together the same way waterbirds do, so there is less chance for the virus to pass between them. Lower isn’t zero, though with an Australian Magpie and a number of Ravens already testing positive. Parrots are a bit more of an unknown. They haven’t shown up much in the big overseas die-offs but in Australia our lorikeets, corellas, galahs and cockatoos are found across a wide range of habitats, and are intensely social, feeding and roosting in big, dense flocks and crowding at the same food trees. They aren’t waterbirds and they don’t feed on other animals, which may be part of why they’ve stayed off the radar so far.

Despite their lower risk of H5 bird flu, an Australian Magpie has already tested positive. Australian Magpies by Pam Goble.

Why are some birds vaccinated and not others? 

As much as we wish it could, vaccination was never going to stop H5 spreading through wild birds; nothing can. What it can do is protect specific populations that are highly managed – with individuals that are able to be captured and then recaptured – that way an at-risk species doesn’t get wiped out locally. That’s one reason why it’s directed at birds in zoos, sanctuaries, breeding programs and predictable colonies, like the Little Penguins at Phillip Island.

There are practical limits, too. For a start, the vaccine must match the strain that’s circulating. It was also developed for poultry, so its effect on other species must be tested rather than assumed. And it takes two doses given weeks apart, which is a real obstacle with wild birds you can’t readily catch and recatch. There has been a prioritisation piece done that mapped the vulnerability of many species of wildlife (so who is likely to get it and what is the impact on the population if they do) to help with the rollout of vaccination plans.  

All of that is the big-picture response though, and it is out of any one person’s hands. There are things that we as individuals can do though. You don’t need to be an expert, and you certainly don’t need to stop enjoying your birds – getting out and watching them is vital. What you do in your own garden and your local area does add up, both for the birds that visit you and for the wider effort.  The rest of this series is about what that looks like in practice. 

Useful links 

• BirdLife’s H5 information hub

• BirdLife’s H5 FAQ (regularly updated)

• BirdLife explainer, “Bird flu is here. What now?”

• Wildlife Health Australia H5 resource centre

• Federal H5 bird flu risk calculations

• Long term population impacts