AI: Will Maine Encounter Avian Influenza from Southerly-Migrating Wild Birds?

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

It’s time to review biosecurity again, as the risk of getting avian influenza (AI) (and other diseases) from wild birds may increase this fall. The outbreak of highly pathogenic AI (HPAI) has calmed down, and Maine (and the East coast) escaped so far. After losses of more than 48 million birds, the US has had no new cases since the week of June 10th. Many of the affected commercial farms are completely cleaned up and restocking with new birds.

Canada geese in flightHowever, even now when the weather is warm, some wild bird species are readying for their southern migrations. As there was HPAI present in the wild migratory bird populations in other parts of the US and Canada this spring, there is certainly a good chance that southerly migrating birds could carry the virus into Maine this fall. Simple measures can decrease the chance of your birds getting infected.

  1. Don’t attract wild birds to your poultry areas. Make sure your feed is stored securely (clean metal garbage cans with tight-fitting tops work great for storage). Put feeders inside the hen house, and keep wild birds out by using bird netting. If you keep a wild bird feeder, put it as far away as possible from your poultry.
  2. Don’t bring disease to your poultry. Dirty boots, tools or even vehicle tires can carry infected manure from other farms, or wild birds, onto your property.
  3. Keep a “closed” flock. Restrict visitors’ contact with your farm, and be very careful if you visit other farms to avoid bringing infections with you. If you buy new birds, quarantine (3 weeks) and test them for parasites or disease before adding them to your flock. Better yet, buy all birds at one time, and clear out the old flock, clean/disinfect/fallow your poultry areas before bringing in new birds
  4. Simple sanitation: handwashing for people, and frequent cleaning of feeders/waterers/nests/bedding for poultry will greatly decrease the chance of disease. Use a simple mask if you are working in dusty areas, or with sick birds, to decrease your chance of getting sick or allergic.

It’s still not clear why so few “backyard” flocks (21 versus 211 commercial flocks) were affected with HPAI this year. We don’t know if this is a “real” effect, due to the low numbers of birds and diverse genetic backgrounds, or an “artifact” of reporting. Viruses can be picky: for instance, this particular virus was reported to be more pathogenic to turkeys than to chickens. Influenza viruses change relatively easily over time, and we won’t know till later what the “fall” version of the H5N8 HPAI virus, that was so problematic this spring, will be. Until then, poultry producers of any size category, from small urban flocks to large commercial flocks, should be focused on reducing the risk of disease with excellent biosecurity.

Read through the National Poultry Improvement Plan (NPIP) guide for more biosecurity ideas ( As well, if you would like to discuss your farm and specific ways you could increase biosecurity, please send an email to with “Poultry Biosecurity” in the subject line.