Department of Environmental Conservation

D E C banner


Causes and Susceptible Species

Salmonellosis refers to disease caused by bacteria in the genus Salmonella. There are many species and strains of Salmonella and a large number of them are at least potentially pathogenic to a variety of animals. In many instances, however, salmonellae may inhabit the digestive tract without causing noticeable disease. Note, for example, the frequent reports of Salmonella in pet turtles. The following discussion will focus on salmonellosis in songbirds caused by Salmonella enterica serovar typhimurium. It is by far the most frequently recognized problem with regard to Salmonella and wildlife in New York.

In recent times salmonellosis has generally emerged in mid-to-late winter in flocks of redpolls and pine siskins that have fled forests to the north. During outbreaks, salmonellosis is sometimes confirmed in other species such as goldfinches and evening grosbeaks. Such so-called spillover has to date remained a very minor feature of these episodes. All of the above-mentioned species typically feed for long periods of time at feeding stations. This is opposed to the come and go habits of chickadees and nuthatches.


The disease is transmitted through fecal contamination of food and bird feeders. Unaffected carriers may play a role in spreading the disease. Predators and scavengers of diseased songbirds may be susceptible to infection. However, there is little evidence of significant morbidity (illness) in those species beyond an occasional diagnosis in house cats.

Outbreaks of salmonellosis in redpolls and pine siskins tend to occur in winters with large winter movements of these species into the northern United States.

Salmonellosis is sporadically confirmed in house sparrows without any noticeable seasonal component. Many outbreaks may be recorded over broad geographic regions and the total mortality by winter's end may be large.


Diagnosis is tentatively made from the characteristic lesions in the esophagus and culture of samples from the digestive tract.

S. enterica sv typhimurium principally infects parts of the digestive tract. In the bird species mentioned above, the most severe lesions are usually in the esophagus. These lesions are sites of thickening and necrosis (premature death of cells). They appear as relatively firm yellowish masses that can often be palpated (touched) and visualized through the skin. Sick birds may appear weak, and they may tend to sit around feeding stations with fluffed-up plumage. At death most individuals are thin despite evidence of continued feeding.

Preventing the Spread of Salmonellosis

When an outbreak of salmonellosis is detected at a bird feeding station, the traditional recommendation is to stop feeding for a minimum of two weeks. Spilled seed and seed husk debris should be cleaned up. Feeders should be disinfected with a 10% solution of household chlorine bleach (1 part bleach/ 9 parts water) and air dried before rehanging. This strategy will disperse the birds, separating uninfected susceptible birds from sick birds and the contaminated feeder environment. Salmonella can infect people, so it is recommended to wear gloves and then wash hands after cleaning and disinfecting equipment.

  • PDF Help
  • For help with PDFs on this page, please call 518-478-2203.
  • Contact for this Page
  • Wildlife Resources Center
    108 Game Farm Road
    Delmar, NY 12054
    Send us an email
  • This Page Covers
  • Page applies to all NYS regions