Published since 1946
Highly Pathogenic Avian Influenza a Growing Concern in Wild Bird Populations
The March Outdoor News Bulletin reported on the viral disease called highly pathogenic avian influenza (HPAI), but its prevalence and impact in the U.S. continues to grow. HPAI has been detected in bald eagles in Georgia and has likely undercut nesting success for eagles in the state’s coastal counties, according to the Georgia Department of Natural Resources. In Georgia’s six coastal counties, annual DNR aerial surveys of nesting bald eagles have revealed more failed nests—those that did not fledge young—than expected. Some nests had dead eaglets. Others were missing young that usually would not have left the nest yet, according to survey leader Dr. Bob Sargent, a program manager with DNR’s Wildlife Conservation Section. Citing preliminary findings, Sargent estimated that nest success along the coast this year is down about 30%. Although the 73 nests documented was normal, he said fewer than half fledged young, compared to an annual average success rate of 78% from 2015-2021.
About a third of the eagle nests in Georgia are in the coastal counties. HPAI is typically carried by waterfowl and shorebirds. Eagles could have contracted the virus by preying or scavenging on dead or sick waterbirds (ducks often gather in large rafts in coastal waters during winter). Dead bald eagles have been confirmed with HPAI in other Southeastern states, including Florida, South Carolina, and North Carolina.
Avian influenza or bird flu can infect wild and domestic birds, as well as other animals. The strain known as highly pathogenic avian influenza, commonly referred to as HPAI, is worldwide, highly infectious, untreatable, and potentially lethal to infected animals. HPAI has been detected in wild birds in more than 30 states this year, the U.S. Agriculture Department reports.
Although current concerns related to this outbreak are centered on preventing spillover to commercial poultry, it needs to be emphasized that this lineage of HPAI represents an emerging disease threat to North American wildlife. In Europe, wild bird mortality associated with GsGD-H5 has been documented in at least 80 species including ducks, geese, swans, and some shorebirds and, in some cases, has been extensive. For example, estimates of influenza mortality in a barnacle goose population in the UK exceeded 10%. More recently, an outbreak in Israel was linked to the deaths of thousands of Eurasian cranes and hundreds of white pelicans and ducks.
A recent manuscript published in the Journal of Wildlife Management stresses the economic and ecological consequences of incursions of HP viruses of concern into North American wildlife and domestic bird holdings and clearly emphasizes the need for North American wildlife managers to be informed. The manuscript stresses the need for remaining proactive and vigilant in efforts aimed at understanding and mitigating such consequences.
To help prevent the spread of HPAI, the public should avoid handling (CDC recommendations for hunters and game birds) and keep pets away from sick or dead birds. Symptoms of HPAI can vary from lethargy to tremors and seizures. However, live birds can be asymptomatic and dead ones may show no obvious signs of trauma.