Avian Influenza and Falconry
Background
Avian Influenza (Avian flu) is a contagious disease occurring naturally in waterfowl, but can affect any bird species (over 100 different species have been identified). Within the U.K and Europe it has predominantly been a disease occurring in Autumn and Winter, carried by wintering water birds during their annual migration. There is a risk it may become endemic in local populations (occurring all year round), again with water birds (ducks, geese, swans) acting as a reservoir for infection.
When an outbreak occurs, it is classified based upon the ability of the virus to cause disease in chickens in a laboratory– low pathogenic causing mild symptoms but high pathogenic causing significant disease and mortality. The pathogenicity of disease in chickens does not necessarily correlate with other birds or raptors. As with influenza virus in humans, there are many different strains that affect different species of birds in different ways, and each year there is the potential for different strains to occur. Due to the significant impact an outbreak can have on the economy of the whole country, the disease is “notifiable”– meaning any suspect case must be reported by law to the authorities for investigation and help stop the potential spread.
Signs of disease and treatment
As with influenza virus in humans, different individuals/species may respond differently to the virus. Water birds are known to act as reservoirs of the virus; they may carry the virus and show no signs of disease at all. Conversely, a raptor may come into contact with the same virus (most commonly through eating an infected bird) and death may be the result. Unfortunately the incubation period (time from contracting the virus to demonstrating signs of disease) can be as little as 24 hours (typically 2472hrs) and in birds of prey, they are affected so quickly that often the first sign of disease is death.
There is no specific treatment for avian influenza.
2020/21 Outbreak
Raptors have been proven to be highly sensitive to the virus with 7 out of the 22 cases identified in wild birds in the UK during the 2020/21 Winter outbreak being in raptors. In captive birds, there were 22 cases of highly pathogenic avian influenza, of which 2 (10%) were in captive birds of prey. Investigations into these cases found the source of infection in the captive raptors to be wild sourced waterbirds (ducks) fed to the falcons.
Risk and Prevention
The risks to falconers’ birds from Avian Influenza are generally low. Certain situations and practices can significantly increase these risks however through a few simple steps the risks can be reduced.
1). AVOID WATERFOWL (Ducks)
Ducks may carry the disease and show no signs of being sick. Many falconers will inspect a carcass to look for signs of disease prior to feeding, however with avian influenza these signs can be subtle with nothing specific to indicate disease– even to the most experienced falconer. FREEZING DOES NOT KILL THE VIRUS. During significant outbreaks (such as 2020/21 season) the Government may issue a directive where contact with wild birds is prohibited by law throughout the whole country. In lesser years, local outbreaks will be monitored and “exclusion zones” put in place where again contact with wild birds is locally prohibited. Falconers are asked to respect these requirements and not hunt any wild bird when/where either of these situations exist. The only safe way to ensure the risk of disease from wild birds is reduced is to feed only commercially sourced food from a reputable vendor.
2). BIOSECURITY
Government guidance on biosecurity and preventing disease in captive birds can be found HERE.
The virus can exist in the environment and be carried on surfaces other than birds. Falconers should practice good hygiene and biosecurity at all times, but specifically when outbreaks of AI are reported. Changing clothes/footwear from the field to the house can help reduce the risk. Use of footbaths outside birds’ accommodation with the correct disinfectants licensed for use against AI at the correct concentrations (see link for approved disinfectants) will also help reduce the risk of transmission.
Attempts should be taken to reduce the risk of vermin or small wild birds entering the housing. Care should be taken when siting accommodation to ensure they are not attractive to other birds by reducing the proximity to shelter such as trees and bushes and removal of food sources. If this is not possible, thought should be given to use of netting to prevent smaller birds entering the accommodation.
Implications for falconry
Despite the risks being relatively low, falconers must be aware of the implications their actions may incur. Whereas an individual hawk that contracts avian influenza may become sick or die, there is also risk to other birds kept at the premises or having been in contact (including field meets etc). If influenza is confirmed, depending upon the level of risk and mitigating factors, in contact birds may be quarantined for observation or even euthanased as a precaution to prevent spread.
Each confirmed case of avian influenza has implications for the whole country with restrictions on international trade and export being imposed. These implications may run into £millions and have significant consequences on the economy.
Falconers have a responsibility towards the welfare of the hawks under their care, but we also all have a responsibility towards the reputation of falconry and ensure our actions do not bring falconry into disrepute.
How to find more information
To sign up for automatic notification of notifiable disease outbreaks please follow the following link:
https://public.govdelivery.com/accounts/UKAPHA/subscriber/new?qsp=CODE_RED
Written by Karl Jennings