Albany — New York’s wild turkey population has declined substantially in recent years, and one factor may be the arrival of a new disease in the U.S.
Lymphoproliferative Disease Virus (LPDV), a tumor-forming virus that affects ground-feeding fowl, has made its way to the U.S. after years of its presence in domestic turkeys in Europe and Israel.
“The initial case was diagnosed by the Southeastern Cooperative Wildlife Disease Study based at the University of Georgia,” DEC wildlife biologist Mike Schiavone said. “It has since been identified in numerous wild turkeys in the U.S. from Colorado to Maine and it’s possible that it has been present but undetected for a long time.”
LPDV was confirmed in New York wild turkeys in 2012. Since that time, DEC’s wildlife health unit and upland game bird team worked together in sending over 2,000 samples from hunter-killed birds to the University of Georgia for its study. Birds killed during the 2012 fall turkey season were also sent to SUNY ESF and Cornell University for testing.
“Preliminary results from these samples show that LPDV appears to infect a large proportion – about half – of the state’s turkey population,” Schiavone said.
The discovery of the disease offers up another potential theory on the decline in turkey numbers in New York state. The spring gobbler harvest peaked in 2003 when 36,800 birds were shot, but has plummeted since then, with 18,738 taken in 2011, 19,038 in 2012 and 21,515 in 2013.
And this past spring just 15,904 birds were taken, the lowest in recent statistical history.
Other historical turkey-hunting hotbeds like Missouri have seen similar declines. Biologists, including Schiavone, have attributed some of that dip to a natural reduction on the heels of peak numbers after wild turkey restoration projects. But habitat loss and predation have also played at least some role, he said.
Poor nesting and brood-rearing conditions (wet and cold) in recent years have also kept turkey numbers down sharply. In particularly, 2009 was the worst since DEC began doing its poult surveys. Although 2010 and 2011 were improved, those production years remained below average.
DEC officials said the 2014 nesting season edged upward, based on annual summer sighting surveys. Schiavone called the 2014 numbers “close to or above the five-year average,” but given the production over the past five years the standard was fairly low.
Schiavone says it’s unclear at this point how LPDV arrived in the U.S. Also not known is how it’s transmitted between birds or the long-term effect on the turkey population.
Several New York hunters in recent seasons have reported killing gobblers with lesions on their face. Those were generally dismissed as carriers of avian pox.
“In some birds, the virus causes tumors to form in internal organs, but many birds that test positive for the virus appear to be healthy,” Schiavone said. “In a few cases, tumors can form on the skin of the birds and mimic avian pox lesions. Since a number of birds with skin tumors also infected with avian pox virus, there may be an interaction between these two viruses in producing the skin form of the disease.”
LPDV isn’t believed at this point to be a human health risk. However, DEC officials advise caution when handling birds with lesions or tumors, and say sick or sick-acting birds should not be eaten.