Health problems in populations of wild animals are not new, and such occurrences are actually quite common.  A subtype of avian flu that spread in Southeast Asia has generated concerns in other countries and led some people here in Northern America to wonder about the impact bird flu may have on wild bird populations.  Below are responses to some of the most frequently asked questions about the potential impact of avian flu on wild birds and bird feeding

What is bird flu?
Bird flu represents a series of genetically similar, invluenza virus subtypes.  The virus is spread from bird to bird by contact with contaminated secretions, such as saliva, nasal secretions, and feces.  For example, the virus has been found in water and fecal material in areas with high waterfowl use.  Avian flu is widespread, occurs naturally in wild birds, and has been known for decades.  Subtypes of bird flu have been found throughout the world, including North America. 

Why is there concern about bird flu?
Since 1997, a subtype of the virus, known as H5N1, has afflicted poultry in Southeast Asia, killed dozens of people, and spread to some surrounding countries.  The concern is that the virus could mutate and cause a pandemic in wild birds or humans.  Normally, strains of bird flu affecting domesticated birds are not deadly for wild avian species.  However, migratory waterfowl, including Bar-headed Geese at Qinghai Lake Nature Reserve in western China, have died from the virus, and concern has been raised about the ability of migratory birds to carry the virus to other parts of the globe.

How does bird flu impact wild birds?
Avian flu is common in birds; however, wild birds do not normally show any symptoms.  Prior to the Asian outbreak, few mortality events of bird flu were known in wild birds.  One of the first recorded mortality events involved a group of Common Terns in South Africa that were killed by the flu in 1961.  The relative occurrence of bird flu varies in bird populations.  Waterfowl and shorebirds frequently have the virus and may act as reservoirs for the pathogen.  The virus is common in gulls and terns and is occasionally found in marine birds, upland game birds (quails and pheasants), and ratites (Ostriches and rheas).  Avian flu is rare or unknown in raptors and songbirds (the majority of birds that use bird feeders and bird baths).  In waterfowl, bird-flu infections occur year-round, with infections being most common during the late-summer months in juvenile waterfowl.  In shorebirds and gulls, the infection rate is highest in the spring.

Given what we currently know about the outbreak of bird flu in Asia, is feeding birds safe?
Like other viruses, avian flu can evolve, and it is possible that a new strain could cause a pandemic in both wild birds and/or humans.  However, at present, given what we know about avian flu, bird feeding is safe for both humans and the birds that visit your feeders.

How can I create and maintain a safe experience for birds visiting my yard?
While bird flu is not a current threat to backyard birds in North America, there are diseases that can afflict birds that use feeders and baths.  To maintain a safe feeding experience for birds, provide them with a large amount of space for feeding, keep feeding areas clean of seed hulls and bird droppings, use feeders that do not have sharp points or edges, regularly clean feeders, store food appropriately, and ensure that fresh seed is in your feeder.