A new pathogen has been discovered by scientists investigating major die-offs of pigeons native to North America, according to studies led by the University of California, Davis, and the California Department of Fish and Wildlife.
Scientists were able to implicate this new parasite, along with the ancient parasite Trichomonas gallinae, in the recent deaths of thousands of Pacific Coast band-tailed pigeons. The die-offs occurred during multiple epidemics in California's Central Coast and Sierra Nevada mountain ranges. Scientists named the new pathogen Trichomonas stableri.
Avian trichomonosis is an emerging and potentially fatal disease that creates severe lesions that can block the esophagus, ultimately preventing the bird from eating or drinking, or the trachea, leading to suffocation. The disease may date back to when dinosaurs roamed the earth, as lesions indicative of trichomonosis were found recently in T-Rex skeletons. The disease may also have contributed to the decline of the passenger pigeon, whose extinction occurred exactly 100 years ago.
Epidemics of the disease can result in the death of thousands of birds in a short amount of time. An outbreak in Carmel Valley killed an estimated 43,000 birds in 2007.
"The same parasite species that killed band-tailed pigeons during the outbreaks were also killing the birds when there weren't outbreaks," said lead author Yvette Girard, a postdoctoral scholar with the Wildlife Health Center in the UC Davis School of Veterinary Medicine at the time of the studies. "This indicates there may be other factors at play in the die-offs."
"We are now investigating what triggers these die-offs, which may be
caused by the congregation of infected and vulnerable birds during
certain environmental conditions, or even spillover from another
nearby species," said principal investigator Christine Johnson, a
professor with the UC Davis Wildlife Health Cen
|Contact: Yvette Girard|
University of California - Davis