State Game and Fish investigators are trying to determine what caused the death of more than a dozen birds recently near a Scottsdale golf course.
They ruled out avian flu, a sickness that has captured worldwide concern because of fears it could change into a disease humans might easily catch.
The deadly West Nile virus is a suspected cause, but the birds may have died from two common, naturally occurring fatal diseases that kill birds starting this time of year, the Arizona Game and Fish Department reported.
“There’s a thousand things that can happen” and could have led to the birds dying in one location, said Jim deVos, chief researcher with the department.
Scottsdale resident Ryan Landefeld said he has found about 20 dead birds in the last 10 days in stagnant water near the Silverado Golf Course at Hayden and Indian Bend roads.
Landefeld said he came across the birds while taking his dog for morning walks near the canal that runs under a portion of the golf course.
On Tuesday, Landefeld said he counted 12 dead birds and reported them to the city.
DeVos said the birds will be sent to a laboratory in Tucson to determine the cause of the deaths.
The results are expected within days, he said.
The West Nile virus is “high on the list of suspected” causes because the area where the carcasses were found is “a mosquito-rich environment,” deVos said.
The virus, which causes encephalitis in humans, is fatal in birds.
Birds serve as hosts for the virus, which is transmitted by infected mosquitoes.
Bird deaths attributed to the virus are considered the first sign of the virus’ presence.
Last year in Arizona, there were 106 human cases of West Nile virus reported and four people died of the disease, according to the Arizona Department of Heath Services.
Thus far this year, West Nile has not been detected in the state — but it will make its presence known soon, said Dave Engelthaler, epidemiologist for the health department.
“We know the risk is out there. There’s no reason to think it won’t pop up anytime soon,” Engelthaler said.
Landefeld’s discovery of the dead birds coincided with a news release issued by the Game and Fish Department alerting Arizonans to possible bird die-offs caused by avian botulism and trichomoniasis.
DeVos said this is the time of year wild birds are most likely to be stricken by those two fatal diseases.
Trichomoniasis, (not to be confused with the sexually transmitted disease in humans), is a naturally occurring parasitic disease that is “the most significant disease problem for mourning doves,” deVos said.
Avian botulism is a fatal bacterial disease birds contract when they eat insects or carcasses infected with bacteria, he said.
Neither disease can be easily transmitted or pose a threat to humans, he said.
DeVos ruled out the possibility of avian flu, or bird flu as its called.
“It’s the wrong time of the year and the wrong setting” for avian flu, he said, adding that the fatal disease, discovered in Asia, has not been detected in North America. DeVos said the department has not received additional reports of widespread or multiple bird deaths elsewhere in the state.