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 Center.
Between winter 2011 and spring 2012, there were eight mortality events — defined as more than five dead birds found in the same geographic area during the same time frame. The study said trichomonosis was confirmed in 96 percent of dead, sick or dying birds examined at seven of the mortality events. This disease was also found in:
“What makes this disease more troublesome for band-tailed pigeons is their low reproductive rate — about one chick per year — and also that these events are occurring in the wintertime,” said co-author Krysta Rogers, an environmental scientist with the California Department of Fish and Wildlife. “That means almost all the birds we’re losing during events are adult birds. They’re being killed before they have the ability to reproduce in the spring.”
Mortality events in band-tailed pigeons have been reported in California at least since 1945, but have increased during the last decade, with outbreaks reported in six of the last 10 years.
“Going into the study, we expected to find a single, highly virulent species of Trichomonas in birds sampled at outbreaks,” Girard said. “Having two species killing birds at these large-scale mortality events is surprising.”
Necropsies of the birds were conducted at the California Animal Health and Food Safety Laboratory at UC Davis and the Wildlife Investigations Laboratory at the California Department of Fish and Wildlife.
Both studies were funded by the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service.
The study naming the new species of parasite is published in the journal International Journal for Parasitology: Parasites and Wildlife. The study that explains how trichomonosis is affecting the band-tailed pigeon is published in the journal Infection, Genetics and Evolution.
UC Davis is a global community of individuals united to better humanity and our natural world while seeking solutions to some of our most pressing challenges. Located near the California state capital, UC Davis has more than 34,000 students, and the full-time equivalent of 4,100 faculty and other academics and 17,400 staff. The campus has an annual research budget of over $750 million, a comprehensive health system and about two dozen specialized research centers. The university offers interdisciplinary graduate study and 99 undergraduate majors in four colleges and six professional schools.
Yvette Girard | Eurek Alert!
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences