November 1, 2002

C.U. Bird Count Will Track West Nile Virus

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In mid-November about 17,000 volunteers in North America will participate in Project Feeder Watch, an annual program conducted by the Cornell Lab of Ornithology to monitor the West Nile Virus.

“We ask people to report numbers of birds at their feeders to get population trends. The decline of populations can maybe then be attributed to the disease [West Nile],” said David Bonter, leader of the project.


Feeder Watch has received increased attention due to the growing number of West Nile cases in recent years.

“The virus is traveling, it has traveled so far, so quickly,” said Wesley Hochachka of the Cornell Lab of Ornithology. There has been an occurrence of West Nile in almost every state in the U.S., sparking more interest in the disease.

The changes in bird populations found through Feeder Watch allow researchers to determine the impacts of West Nile and other diseases on birds.

“It is important to know populations of birds before West Nile as well as after West Nile.” said Dr. Kevin McGowan, also with the ornithology lab.

Counts such as Feeder Watch compare bird population numbers from different years to see how bird populations are affected.

“We are planning, after a month, to compare numbers of birds this winter with the last 15 years of information, to see an impact of West Nile,” Hochachka said.


By comparing numbers of birds in certain areas with previous years, it can be seen whether reported diseases have large effects on birds. With the data compiled through Feeder Watch and other non-University programs like Christmas Bird Count and Breeding Bird Survey, scientists have information to compare population trends to track diseases in North America.

“Feeders are mostly used in winter, when birds look for alternative food resources,” said McGowan. During the winter, insects are scarce so birds use feeders more often, giving scientists and volunteers an opportunity to count them.


McGowan stressed the program’s consistency, saying “Feeder Watch has a standard protocol. The same thing is done year to year.”

West Nile is a virus that is transmitted from mosquitoes to birds, humans, horses and other animals. “West Nile is not primarily a human disease. It is primarily a bird disease transmitted from bird to mosquito, mosquito to bird, bird to mosquito, etc.” McGowan said.

Though the media has portrayed the disease as a serious danger to humans, it has had a greater effect on the feeder bird population in North America in the past few years.


“West Nile is a virus that originated in the Middle East around the Nile River. It was introduced in New York in 1999, and that was when we realized the disease was here [in the U.S.],” Bonter said. The disease was discovered when large numbers of dead crows were reported in the New York City area.

Archived article by Cheryl Mensah