Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Die-offs of band-tailed pigeons connected to newly discovered parasite


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.

Researchers at UC Davis and the California Department of Fish and Wildlife have identified trichomonosis as a key factor in winter die-offs and population decline of bandtailed pidgeons, a native migratory game bird. (Dianne Ricky/courtesy photo)

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:

  • 36 percent of band-tailed pigeons at wildlife rehabilitation centers
  • 11 percent of hunter-killed band-tailed pigeons
  • 4 percent of the birds caught live and released

“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.

About UC Davis

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.

Additional information:

Media contact(s):

Yvette Girard | Eurek Alert!

Further reports about: Fish Trichomonas Wildlife lesions mortality parasite pigeons species

More articles from Ecology, The Environment and Conservation:

nachricht Taking a molecular approach to conserving freshwater biodiversity
09.11.2015 | Universiti Putra Malaysia (UPM)

nachricht Faster digestion in kangaroos reduces methane emissions
05.11.2015 | Universität Zürich

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

Im Focus: Climate Change: Warm water is mixing up life in the Arctic

AWI researchers’ unique 15-year observation series reveals how sensitive marine ecosystems in polar regions are to change

The warming of arctic waters in the wake of climate change is likely to produce radical changes in the marine habitats of the High North. This is indicated by...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Harnessing a peptide holds promise for increasing crop yields without more fertilizer

25.11.2015 | Agricultural and Forestry Science

Earth's magnetic field is not about to flip

25.11.2015 | Earth Sciences

Tracking down the 'missing' carbon from the Martian atmosphere

25.11.2015 | Physics and Astronomy

More VideoLinks >>>