Injury, Disease & Mortality
Diseases | Mortality | Raptors | Shorebirds | Waterbirds
West Nile Virus
- (Area - Nationwide) - West Nile virus (WNV) is a mosquito-borne infection that can cause encephalitis (inflammation of brain tissue) and/or meningitis (swelling of the tissue that encloses the brain and spinal cord). Endemic to parts of the Old World, WNV was first detected in North America in the summer of 1999, in New York City, NY; a dead crow at the Bronx Zoo was one of the first harbingers of what was to come. Within three months, WNV had spread to Connecticut and New Jersey, leaving tens of thousands of dead birds in its wake. Over the subsequent four years, it has continued to spread across the continent, and by the end of 2003 had been detected in 46 U.S. states, the District of Columbia, and seven Canadian provinces (Nova Scotia, New Brunswick, Quebec, Ontario, Manitoba, Saskatchewan, and Alberta). Handling Birds
- Protection Measures During Field Surveys
Avian Vacuolar Myelinopathy (AVM) (Area - Southeastern United States)
What is AVM?
AVM, formerly known as Coot and Eagle Brain Lesion Syndrome (CEBLS), is an avian disease that is believed to be caused by a neurotoxin of unknown origin. It causes lesions (open spaces) in the white matter of the brain and in the spinal cord of affected birds. Affected birds have difficulty flying, walking and swimming. AVM is the most significant unknown cause of eagle mortality in the history of the United States. AVM was initially confirmed in bald eagles (Haliaeetus leucocephalus) and in American coots (Fulica americana) by the U.S. Geological Survey National Wildlife Health Center (USGS NWHC) in the fall and winter of 1994. As the name change indicates, AVM continues to evolve. It was confirmed in several duck species in 1999 by NWHC and the University of Georgia’s Southeastern Cooperative Wildlife Disease Study (SCWDS). These species include Mallard (Anas platyrhynchos) and ring-necked ducks (Aythya collaris). Lesions consistent with the disease were also found in bufflehead (Bucephala albeola) and American wigeon (Anas americana) ducks, and in Canada geese (Branta canadensis).
Birds with avian vacuolar myelinopathy typically fly erratically or are unable to fly completely. According to USGS wildlife disease specialist Dr. Kimberli Miller, birds may crash land, swim tipped to one side with one or both legs or wings extended, or be in the water on their backs with their feet in the air. The disease affects the brain and spinal cord by damaging the myelin sheath that insulates the nerve fibers. It is diagnosed by microscopic examination of very fresh brain and spinal cord tissue.
Lead Poisoning (Area - Nationwide)
Symptoms of lead poisoning can range from lethargy and depression, inability to perch (unexplained falls from perches) to seizures and death. The initial treatment will depend on whether it is an acute case of lead poisoning (usually after ingestion of a lead-containing foreign body) or chronic lead poisoning (repeated small exposures - often from eating food or drinking water from lead-soldered dishes).
Avian - Mortality
Housecats are responsible for killing many thousands of birds each year. The American Bird Conservancy operates a program called “Cats Indoors” to educate cat owners on this issue.
The U.S. Fish and Wildlife Service (USFWS) estimates at least five million birds and as many as 50 million birds are killed annually in collisions with communications towers in the United States. Relevant information on this issue can be found at www.abcbirds.org/policy/towerkill.htm and http://www.abcbirds.org/conservationissues/threats/towers.html
Some pesticides can, and do, kill birds - songbirds, gamebirds, raptors, sea and shorebirds, among others. 672 million birds are directly exposed each year by pesticides on farms alone - according to one conservative estimate - and 10% of these, or roughly 67 million birds, die. According to the U.S. Fish & Wildlife Service, approximately 50 pesticides currently used in the United States have caused bird die-offs. Additional information can be found at http://www.abcbirds.org/abcprograms/policy/pesticides/index.html
This section provides information on what to do if an injured raptor is found on Corps of Engineers or DoD lands.
Some tips for handling injured raptors (adapted from Univ. of Minnesota Raptor Center):
What to do with an injured bird
Raptor Trust – What to do with an injured bird
Southeastern Raptor Rehabilitation Center
- Please do not attempt to rehabilitate a raptor on your own. Always contact a licensed professional. If you are unsure of who to notify, you can contact The Raptor Center, or an appropriate agency in your area, such as the U.S. Fish and Wildlife Service (USFWS), your state's Department of Natural Resources or Department of Game, Fish and Parks, or your local sheriff's office. If you must handle or move a bird, first cover the bird with a blanket or towel to reduce its visual stimulation, and protect yourself by wearing heavy gloves and safety glasses. Then, gently fold the bird's wings into its body with your two gloved hands and gently but firmly lift the bird into a transport container. Remember: Even a seriously injured raptor is potentially dangerous. Wild birds are quite unpredictable, and you should be especially aware of their sharp beak and talons. The best way to transport a raptor is in a plastic dog or cat kennel, or a sturdy cardboard box. Avoid bird or wire cages as these can cause feather and soft tissue damage. The carrier should have plenty of ventilation holes and should only be slightly larger than the size of the bird. The less room an injured bird has to move around, the less likely it is to cause more injury to itself. However, if a container is too small, a bird can sustain extensive wing and feather damage. Never feed an injured raptor unless you have been instructed to do so by a licensed rehabilitator. The dietary needs of raptors are more delicately balanced than people realize. Also, most injured birds are suffering from dehydration, and attempting to feed them or give them water orally may worsen their condition. Handle an injured raptor as little as possible. Stress resulting from human contact can reduce a bird's chance of recovery. Until the bird can be transferred, provide it with a dark, quiet, calm, warm environment. Darkness has a calming effect on birds. Extra care should be taken to keep the bird away from children and pets.
- Do not keep a raptor any longer than is necessary to get it to a veterinary professional, raptor rehabilitator, or State/federal wildlife representative.
Rehabilitation - Research & Management
The Raptor Center, University of Minnesota - Established in 1974, The Raptor Center at the University of Minnesota College of Veterinary Medicine specializes in the medical care, rehabilitation, and conservation of eagles, hawks, owls, and falcons. In addition to treating approximately 800 birds a year, the internationally known program provides training in raptor medicine and surgery for veterinarians from around the world, reaches more than 150,000 people each year through public education programs and events, and identifies emerging issues related to raptor health and populations. The majority of its funding comes from private donations.
California Raptor Center, UC Davis - The California Raptor Center (CRC) is dedicated to the rehabilitation of injured and orphaned raptors. The Center receives over 250 injured or ill raptors each year and is able to release over 60 percent of these birds. The Center provides hands-on training in the care and management of birds of prey and provides educational programs to the general public and the university community.
Like other birds, raptors die from factors not related to natural longevity. Electrocution, lead poisoning and collision with various structures, such as towers, wind-driven turbines and glass panels in buildings can result in premature deaths of birds of prey.
Electrocution - Perching and flying near electric utility lines can be hazardous to raptors.
American Bird Conservancy Policy
Cell Towers/Microwave Towers
U.S. Fish and Wildlife Service Recommendations On Communications Tower Siting, Construction, Operation, and Decommissioning
Market hunting in the late 1800s likely caused declines in many species of large and medium-sized shorebirds and contributed to the possible extinction of the Eskimo Curlew. Current loss or alteration of grassland, wetland, and beach habitats in the temperate United States is a major threat to the stability of shorebird populations. Because shorebirds migrate long distances, habitat loss could be compounded throughout the flyway. The habit of many species to concentrate in coastal estuaries and inland wetlands makes them vulnerable to catastrophic events like large shifts in water-level management and oil spills. Increasing sea level and arctic temperatures associated with global warming could have severe consequences for shorebirds that migrate through or winter in coastal estuaries and breed in tundra habitats.
Threats to Shorebirds:
Shorebirds, both migratory and resident, are threatened in developed countries around the world, where they face disturbance, destruction, or alteration of habitat. Many resident shorebirds breed between April and September, some nesting in the open on beaches and along bays, laying their eggs in simple scrapes on the sand or shell grit. They are threatened by predators such as foxes, rats, dogs and cats, increased numbers of native predators such as gulls and crows, and crushing of nests and young by humans, livestock, and vehicles.
Loss of habitat (Photograph courtesyWetland Environmental Education Centre)
The loss of habitat through changes in land use is the most severe threat to the conservation of shorebirds. Drainage of wetlands for farming and commercial development continues in most countries. In contrast to habitat loss in the temperate and tropical regions, there has been less impact in the high artic region, where the great majority of migratory shorebirds breed. However, expansion of oil and gas developments could adversely affect shorebirds on their breeding grounds.
Degradation of habitat
As shorebird habitat becomes unhealthy or disappears, the remaining land attracts more and more birds which creates more problems.
Threats due to pests (plants and animals) ("Weeds on Wetlands" Photograph courtesy Wetland Environmental Education Centre)
Wetlands throughout the world have been affected by exotic weed species. These plants can change the wetland for a long time and it can be very difficult, and expensive, to get rid of them again. Dogs, cats, and other animals in the wrong place can cause many problems to shorebirds resting or feeding.
Shorebirds, their eggs, and chicks are traditionally harvested or collected in several countries because they can be good for food, or can be sold. In some countries, hunting occurs only for sport, under strict rules, but in other countries shorebirds are caught without any rules. Shorebirds often rest or feed together in large numbers, which makes them vulnerable. Harvesting of birds, combined with decreased habitat, can make some species decline quickly towards extinction.
Coastal ecosystems, islands and estuaries are likely to be affected by climate changes and increased sea levels. Global warming may also lead to increased salinity. More information is required about the effects of climate change on shorebird habitat.
Like other birds, waterbirds are adversely affected by factors not related to natural longevity. Waterbird mortality results from a variety of diseases, including Newcastle's disease, avian cholera, algae poisoning and West Nile Virus. Sport and food hunting of some species of waterbirds does occur in various parts of the country. However, these are legal endeavors, regulated by federal migratory bird harvest limits. Waterbirds continue to be at risk from human activities. Debris ingestion/entanglement, oil and hazardous material, and pesticide and fertilizer contamination can cause mortality and also adversely affect reproduction.
At a Glance
Types of Birds
Policy & Procedures
Special Status Species
Imp. Bird Areas
Non-Native and Nuisance Species
News / Current Issues
Habitat Restoration Opportunities
Injury, Disease & Mortality
Inventory & Monitoing
Good Enough to Share
Research & Management