Each spring, the wood thrush returns to Tennessee — famished.
Who wouldn't be, following a 2,000-mile journey that includes crossing the Gulf of Mexico in a single night?
This time of year, bird feeders can be an important energy source for migrating songbirds. But as much as feeders help, they can also hurt, spreading disease and parasites when not properly cared for.
To help keep your backyard birds happy and healthy this season, here are some tips on how and when to clean your feeder, plus the best refueling foods for spring migrants.
The four most common diseases transmitted through overcrowded or soiled feeders are mycoplasma conjunctivitis, avian pox, salmonella and aspergillosis.
Conjunctivitis: Though primarily a respiratory infection, this bacterial disease causes birds to have red, swollen, runny or crusty eyes. The infection is not harmful to humans, nor does it kill birds directly. However, infected birds are more susceptible to starvation or predation due to their weakened vision.
Avian pox: Similar to conjunctivitis, this virus impacts birds' eyes, causing wart-like lesions on unfeathered parts of the body. It is spread through inspects that bite, such as mosquitoes or mites, and can be transmitted via direct contact with infected birds or contaminated surfaces. Though, like conjunctivitis, there is no evidence it can infect humans.
Salmonella: Spread most commonly through feces, this pathogenic bacteria can infect birds, mammals and reptiles. Songbirds are more susceptible to the disease during winter months when they tend to congregate at food sources — like bird feeders. Infected species may be have ruffled feathers, lethargy and diarrhea.
Aspergillosis: This fungal infection, affecting the respiratory system, is not contagious. Rather, it is spread through damp or wet seed mixtures. Sick birds experience diarrhea and difficulty breathing and die quickly. It can affect humans, though typically only those whose immune systems are already compromised due to autoimmune diseases or chemotherapy.
What birds crave
Following their migrations, birds need high-energy foods. Good options include sunflower kernels, shelled peanuts, pumpkin seeds, hempseed fruit, and suet, which is made from fat.
Which feeders are best?
The most hygienic bird feeders are made from non-porous materials such as plastic, ceramic or metal, rather than wood or clay, which are more difficult to clean. Moreover, small feeders tend to be safer as they empty quickly, leaving less time for seed to spoil. Finally, hang more than one feeder to avoid overcrowding. Social distancing, it turns out, is effective in limiting the spread of disease among our feathered friends, too.
* And one more thing: Though not bacterial, each year, between 100 million and 1 billion birds in the U.S. die from window strikes. Remember to locate your feeders at least 30 feet away from windows, or within 1-3 feet of windows. Thirty feet is too far for a bird to mistake its reflection for competition, while 3 feet is too close. It also helps to hang blinds or curtains inside your home, which fragment the window's reflection.
* Bird feeders made out of non-porous materials, such as plastic, ceramic or metal, should be cleaned about once a month. The National Wildlife Health Center recommends rinsing the feeder with soapy water, then dunking it in a nine-to-one water-bleach solution.
* Wood feeders should be cleaned with non-fragranced biodegradable soap or dunked in a three-to-one water-vinegar solution, and should be dried completely before filling with seed.
* Hummingbird feeders should be cleaned once a week or every time it's emptied, whichever happens with greater frequency. The Audubon Society suggests rinsing it with hot tap water and avoiding dish soaps, which can leave harmful residues.
* And one more thing: Never buy nectar with red coloring, which is harmful to birds. The simplest and safest option is to make the nectar yourself, using 1/4 cup refined white sugar to every 1 cup tap water.