Skyrocketing bird-flu toll surpasses 7.6 million; see when migrating birds are most likely to spread it in your area

Weather radar network can track heavy migration of birds, which can spur the spread of avian influenza;
click the image to enlarge it or click here for the interactive version.

Cases of highly pathogenic avian influenza (HPAI) more than doubled last weekend to 7.65 million birds in 15 states. Egg-laying hens account for two-thirds of the cases, echoing the last major outbreak in 2014 and 2015. "Since the first outbreak was confirmed in U.S. domestic flocks on Feb. 8, the largest losses have been in Wisconsin, followed by Delaware with 1.4 million birds, Maryland with 1.3 million, and Iowa with 965,741 birds. Fifteen states have seen outbreaks," Chuck Abbott reports for the Food & Environment Reporting Network.

The virus is blasting through commercial operations and backyard flocks alike. Infected birds generally die from it, and there is no readily-available vaccine. Since HPAI can quickly destroy entire flocks, "Agricultural officials ruthlessly cull infected flocks in hopes of preventing the disease from spreading," Abbott reports. It could get a lot worse, too: More than 50 million poultry died in the 2014-2015 epidemic, either because of illness or through preventative culls.

The virus can spread through contact with infected birds, or contaminated clothing, equipment and vehicles. But the virus is thought to be spreading so widely because of droppings from migratory birds, David Pitt reports for The Associated Press. Migratory birds such as ducks or geese can catch the virus without any ill effects, and can spread it to poultry through feces or shed feathers when flying overhead. Infected wild birds have been found in 21 states.

Since migratory birds are spreading it, poultry owners should keep an eye on when such birds are most likely to be on the move, Rae Yost reports for KELO in Sioux Falls, South Dakota. BirdCast might be a good way to do that. The website, created mostly by members of Cornell University's Lab of Ornithology, features bird migration forecast maps, live bird migration maps, and local bird migration alerts. Check it out here.