San Luis Obispo (SLO) Tribune, Feb 18, 2015 (emphasis added): I am a volunteer at Pacific Wildlife Care… there is an ongoing problem throughout California with band-tailed pigeons that have grown sick or are dying of Trichomoniasis – a protozoan that causes lesions to form in the throat and nasal passages.
San Francisco Chronicle, Feb 2, 2015: Mass pigeon deaths alarm biologists — An alarming increase in the number of dead and dying band-tailed pigeons along the California coast… apparent victims of a parasite… The sudden increase in mortality is disturbing, [Krysta Rogers, Calif. Dept. of Fish & Wildlife] said… “[It] is very concerning… Right now, it’s really hard to estimate mortality because… if there are deaths in remote locations, we’re not getting reports.”… [The parasite] lives in the mouth and throat of infected birds, causing lesions in the mouth or esophagus that eventually block the passage of food. Infected birds die from starvation or suffocation.