Bird flu, also known as avian influenza, is a highly contagious viral disease that can infect wild birds like hawks and potentially spread to domestic poultry and other animals. There are concerns that certain bird flu strains, such as H5N1, could mutate and cause a pandemic in humans. Understanding how different bird species, like hawks, interact with and spread bird flu is important for managing outbreak risks.
Can hawks get bird flu?
Yes, hawks can contract bird flu just like other bird species. Avian influenza viruses typically infect birds and are spread between birds through direct contact or through contact with infected bodily fluids and feces. Wild hawks may come into contact with infected waterfowl, poultry or other birds and pick up bird flu that way. The virus can then replicate inside a hawk’s body, causing symptoms and making the hawk contagious to other birds.
Several raptor species, including hawk species like Cooper’s hawks, red-tailed hawks, northern goshawks, and great horned owls, have tested positive for H5N1 avian influenza during past outbreaks in Asia, Europe and North America. Not all infected hawks show symptoms, but some may develop neurological signs, difficulty breathing, diarrhea and may die from the virus. Overall, hawks appear to have a relatively high mortality rate from H5N1 flu infections compared to some other wild bird species.
How do hawks spread bird flu?
Hawks spread bird flu the same ways other birds transmit the virus:
- Direct contact – Infected hawks can spread virus to other birds through direct physical contact and bodily fluid/feces exposure.
- Contaminated environments – Hawks can shed avian flu virus in their saliva, mucous and feces which can then infect other birds inhabiting the same environment.
- Migration – Hawks capable of long distance migration (e.g. Swainson’s hawks) could potentially spread virus to new regions during migration periods.
The role hawks play in spreading bird flu likely depends on the species and their behavior. For example, hawks with small home ranges and limited contact with other birds may pose less of a transmission risk than highly mobile, social raptor species. However, more research is needed on how different hawk species interact with poultry operations, migratory flyways and backyards to fully understand their infection and transmission potential during outbreaks.
What species of hawks pose the greatest risk?
Certain hawk species may be more likely to transmit avian influenza based on their susceptibility, behavior, habitat and migration patterns. Species potentially posing a higher risk include:
- Cooper’s hawks – Often live near backyard poultry and urban areas, increasing contact with domestic flocks. Also susceptible to H5N1 with deaths reported.
- Red-tailed hawks – One of most common hawk species with a widespread habitat, raising probability of exposure at poultry facilities.
- Northern goshawks – Susceptible to H5N1. Migrate between Europe and Asia, possibly spreading virus between regions.
- Swainson’s hawks – Migrate long distances across North and South America. Could carry viruses to new areas during migration.
However, all hawks near an active outbreak should be viewed as potential transmission risks until more data is available.
Have hawks caused major bird flu outbreaks?
There is no evidence that hawks have been the primary cause of major bird flu outbreaks so far. However, hawks may still play a contributing role in spreading and transmitting avian influenza viruses during epidemics. A few potential ways hawks could influence an outbreak include:
- Introducing virus to poultry – Hawks preying on infected wild birds could pick up virus and then expose backyard or commercial flocks to an outbreak strain when hunting.
- Amplifying local infections – Hawks may become infected, shed virus into the local environment and help propagate the outbreak among regional wild bird populations.
- Long distance spread – Migratory hawk species moving between wintering and breeding grounds could potentially transport bird flu to distant, new locations.
More hawk surveillance during future outbreaks and studies on hawk-poultry interactions will help clarify if certain hawk behaviors significantly amplify epidemics. But for now, it appears waterfowl, poultry trade and farming practices are likely still the foremost factors driving major bird flu outbreaks while hawks play a secondary role.
Should hawks be culled to control bird flu?
There is no scientific evidence that culling hawks would effectively control or stop an avian influenza outbreak. Wholesale culling of hawks is not recommended for several reasons:
- Hawks do not appear to be primary outbreak drivers, so their removal may not impact transmission.
- Culling is extremely resource intensive and often inhumane.
- Removing hawks may have negative ecological impacts on ecosystems.
- Other wild birds and poultry trade still pose infection risks.
- Culling provides a false sense of security over more effective control measures like biosecurity, surveillance and restricting poultry movement during outbreaks.
Targeted control of known infected hawks near poultry facilities may be warranted on a case-by-case basis. But broad hawk culling programs are generally not recommended by wildlife experts and agriculture authorities.
How can bird flu spread from hawks to poultry be prevented?
While the role of hawks in outbreaks remains uncertain, some steps poultry producers can take to reduce the risk of hawks transmitting bird flu include:
- Covering outdoor access areas with netting or roofs.
- Discouraging hawks from nesting on or near poultry facilities.
- Removing small outdoor water sources that may attract wild birds.
- Using enclosed barns and coops to restrict contact between poultry and wild birds.
- Practicing strict biosecurity measures like changing clothes/footwear, cleaning equipment, and limiting visitors.
- Avoiding placing poultry pens near ponds, wooded areas and known hawk nesting sites.
- Reporting any dead or sick hawks on the premises to agriculture authorities for testing.
For backyard hobbyists, keeping chickens and poultry enclosed or indoors, installing hawk deterrents, and avoiding contact with wild waterfowl can help protect small flocks.
Conclusion
Hawks are susceptible to avian influenza and can become infected, shed virus and potentially spread outbreak strains to other birds. However, hawks likely play a secondary role and have not been identified as primary drivers of major bird flu epidemics so far. While hawks may transmit virus at local levels, wholesale culling is not an effective disease control strategy. More rigorous biosecurity practices, poultry movement restrictions and monitoring wild bird populations can help limit hawk and poultry interactions and reduce transmission risks during bird flu outbreaks.