Thank you to readers Lisa and Eliza for correctly identifying the songbirds posted in A Tale of Two Wrens. Our feathered guests are House Finches.
Last week I rescued a finch from our walkway. It sat fluffing its feathers but not otherwise moving. I brought him inside, made him a little nest inside our cat carrier and drove to the local wildlife rescue and rehabilitation facility. I learned a few days later that the sweet little songbird suffered from a highly contagious and generally incurable eye disease called mycoplasmal conjunctivitis or MG. Our rescued finch has been humanely euthanized by the caring folks at Wildlife Center Silicon Valley.
There is small comfort knowing he died in a pair of loving hands. Left on the cold sidewalk he would have surely fallen prey to a cat. Further, since it’s highly contagious, removing any diseased bird from a community gives the others a fighting chance.
Here’s what I’ve learned:
House finches with mycoplasmal conjunctivitis will exhibit swelling around the eyes, crusty eyelids, and watery ocular and/or nasal discharge. Extreme swelling and crusting can lead to impaired vision and at times blindness. In severe cases, birds may become debilitated, depressed, lose body condition, and die. Some birds can act as carriers of MG while showing no clinical signs of the disease.
Mycoplasmosis is diagnosed based on clinical signs and the isolation of M. gallisepticum by culture or other laboratory tests.
Treatment of wild birds with MG is not recommended. Although antibiotics may clear clinical signs, birds can become asymptomatic carriers that can spread the bacteria to new locations.
Management efforts to control mycoplasmal conjunctivitis in finches focus on transmission prevention. Bird feeders and baths should be kept clean and spaced far enough apart to prevent crowding. Only clean, fresh feed should be provided at feeders. Tube-style feeders seem to be particularly problematic in MG transmission. During outbreaks of mycoplasmosis, bird feeding should be discontinued to eliminate this source of transmission.
We don’t feed song birds via a feeder, but we do have a hanging bird bath and a bubbling fountain. I’ll need to be more diligent keeping them clean. Holly Cormier of the WCSV confirmed that vinegar is just as effective as bleach, and it’s non-toxic. You need to let it sit 15 minutes, then thoroughly rinse with a blast of a garden hose.
Armed with this new information, I was anxious to learn of the wellbeing of our second House Finch. He arrived in December and continues to sleep under the eaves each night. Most nights he’s facing in so I can’t see his face. I finally captured this photo showing no outward signs of MG.
His healthy presence brings a bit of joy to each day.
- How to safely clean a bird bath
- House Finch identification
- To Feed or Not to Feed
- If you’re local to the Bay Area/Silicon Valley: Wildlife Center Silicon Valley
Please consider sharing this post with anyone attracting songbirds to their garden.