Cold temperatures promote spread of a bird pink eye pathogen at winter feeders

by Felicia Spencer, Virginia Tech
February 11, 2025

A pathogen for bird pink eye remains viable on bird feeders in winter conditions much longer than in summer conditions without losing any of its severity, according to a recent study.

“In colder temperatures, birds essentially have a much longer window of time — up to seven days — to encounter this pathogen on a bird feeder,” said Sara Teemer, who will receive a Ph.D. in biological sciences in May. “However, that window appears to be much shorter — only up to two days — on feeders in warmer temperatures.” 

Teemer was the lead author of the recently published study in Ecosphere detailing the findings that the pathogen Mycoplasma gallisepticum, which causes a type of bird pink eye, remains pathogenic on feeder surfaces at cold ambient temperatures for up to one week, much longer than previously documented. The findings have strong implications for house finches, which require more food in colder months as they expend more energy to maintain their body temperature, just when their natural food sources become scarce. 

Another finding in the study revealed the pathogen incubated on feeders at colder ambient temperatures caused more severe disease in birds compared with the pathogen incubated on feeders at warmer temperatures. 

“I was definitely surprised when the pathogen, which we swabbed off of a bird feeder after a full week of surviving outside the host, caused disease in birds that was just as severe as if the pathogen hadn’t spent any time on a bird feeder,” said Dana Hawley, professor of biological sciences and co-author of the study.

Keep reading: https://news.vt.edu/articles/2025/02/published-research-ecosphere-dana-hawley-mycoplasmal-conjunctivitis-pathogen.html

Read the Ecosphere paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.70139