Hurricanes blew tiny deer-killing bugs into Hudson Valley, expert suspects

CATSKILL — A virus that rapidly kills deer has spread to the northern Hudson Valley.

The state Department of Environmental Conservation confirmed Thursday that epizootic hemorrhagic disease was found in deer in Greene, Columbia and Dutchess counties, as well as on Long Island. The DEC reported in early August the disease had killed two deer in Ulster County.

The DEC has received reports of more than 700 dead deer in the state and are investigating suspected cases in Albany, Rensselaer, Orange, Sullivan, Rockland, Putnam and Westchester counties.

Though EHD cannot infect humans, it causes fever and hemorrhaging in deer, which can appear lame or dehydrated and often seek out water sources before perishing. Deer can die within 36 hours of infection, according to the DEC.

Traditionally found in Southern states, EHD is relatively new to New York, the first case not appearing until 2007. The virus may have arrived by hurricane, according to DEC Game Management Section Head Mike Schiavone.

Deer are infected with EHD by biting midges, and the miniscule insects were most likely blown into the Northeast by hurricanes or other large storms, Schiavone said.

"That may be what happened again this year," he said, though he added it was also possible biting midges blown in from previous years' storms were able to survive the winter cold, which generally kills off the insects. "At this point we're not sure.”

It is difficult to compare recent outbreaks in New York to outbreaks in the South, Schiavone said, since EHD is endemic in that region and many deer have acquired immunity to the virus over time.

"Deer in the South have developed resistance to the virus, so they don't get too sick ... [in New York] there's no real resistance, so we see larger mortality events," he said. “This may change over time if we see annual outbreaks in New York."

After small outbreaks in the state  in 2007 and 2011, 1,500 deer were killed by the virus in the lower Hudson Valley in September and October 2020, according to the DEC. With at least 700 deer deaths suspected from the disease with the first frost still weeks away, the 2021 outbreak could be much larger.

At this point, Schiavone said he does not believe the outbreak will affect the regular hunting season that begins Nov. 20. 

The DEC manages the deer population by regulating the number of deer that can be killed in a particular section of the state. The agency hands out Deer Management Permits, also called tags, each year, the number of which is adjusted depending on the fluctuating deer population.

Schiavone said he does not foresee the number of tags being limited this year because of the outbreak.

Sightings of sick or dead deer suspected of having EHD can be reported to DEC on their new online reporting form or by contacting the nearest DEC Regional Wildlife Office.