Salmonella Outbreak Diminishing Pine Siskin Population
The Pine Siskin is a small songbird with brown and yellow streaks. They are most commonly found in evergreen or deciduous forest with open canopies. Pine Siskin are very opportunistic and will work hard in their search for seeds. They spend much their winter flocking to birds feeders to maintain their weight through the winter. However, these birds are becoming less frequent in their common habitats.
After receiving multiple calls about sick birds and receiving a diseased Pine Siskin, Dr. White became concerned for the wellbeing of these birds. She suspected that there was some disease being transmitted to these birds this winter and she was right. With a little bit of research, it was discovered that this year there has been an increase of small birds with symptoms of Salmonellosis.
When we hear about salmonella, we think about undercooked chicken or eggs that can make people sick. But it can also affect other species and its often more deadly. During the years where finches are populating and migrating longer distances south than normal We have noticed an increase in salmonella outbreaks. This winter we are seeing a large eruption of winter finches, who are traveling so far that scientists are calling it a “super-flight”. The reason for these disruption is up for debate, but one idea is that there is less food availability.
During this time, birds are experiencing more stress to find food for the winter which is why they are flying further distances than they normally do. This stressor makes them more susceptible to disease and transmitting it to others. Salmonella can affect birds in different ways, bigger birds pass the bacteria through their feces and have no physical symptoms. However, smaller birds that are infected usually do not recover. The species affected include American Goldfinches, Common Redpolls and Pine Siskins. In Washington, we will see the effect on Pine Siskins and American Goldfinch since they are native species here.
Salmonella is transmitted through fecal matter, one obvious place of transmission is at bird feeders. This is not the primary reason that these birds are getting sick, but it is a good idea to clean your bird feeder every once in a while in order to rid the surface of any bacteria. To recognize if one of the birds that visits your feeder is sick, watch for birds that are fluffed up, thin, depressed, have swollen eyelids, and are easily approachable. Call a wildlife rehabilitation center if you suspect that a bird has salmonella. If you find a dead bird, pick up with gloves, place in a bag and put it in the garbage. This disease can be transmitted to outdoor pets and humans so make sure after washing bird feeders or touching birds to wash your hands.
Photo credit: Adults. Photo: Judith Roan/Audubon Photography Award