The probable cause of death of finches, pine siskins and other birds in North Carolina has been identified.

Tests earlier this week by the N.C. Department of Agriculture Consumer Services Food and Drug Protection Division found salmonella bacteria present in Wild Birds Unlimited Wildlife Blend produced by Kentucky-based Burkmann Feeds.

Burkmann is recalling 20-pound bags with the manufacturing date code 81132200291608124 sold exclusively at Wild Birds Unlimited franchises throughout the state. Other Burkmann feeds are being tested.

Bill Kastern, a biologist and Wild Birds Unlimited franchisee in Aberdeen, said his blend comes from a supplier in Pennsylvania. He maintains that local bird deaths are probably from avian salmonella attributed to the unusually large number of finches wintering in the Sandhills.

Avian salmonella infects other animals but rarely humans.

Joe Reardon, food and drug protection director of the N.C. Department of Agriculture and Consumer Services, concurred.

"You may have two things going on at one time in your area," he said.

Reardon said the Burkman seed could contain peanut products from a Georgia plant where salmonella was found. An investigation is under way.

This strain poses a risk to humans and animals. Anyone coming in contact with contaminated bird seed should wash hands thoroughly. Once contaminated seed is disposed of, feeders, poles and bird baths should be washed with a 10 percent bleach solution and rinsed.

Residents who feed wildlife are cautioned to maintain sanitation and keep household pets away from feeders, bird droppings and dead birds.

In a new development, Pinehurst resident Joan Fuchs reported Wednesday that she has seen more than a half-dozen sick or dead birds near her feeder. She purchases thistle seed at Sandhills Feed Co. in Southern Pines.

Store owner Janet Fowler said they have had no problems with any seed but are double-checking with their suppliers.

"There's a lot of confusion out there," she said. "We don't believe the problem is linked to thistle seed. It's the one species that are in such close contact and spreads the salmonella."

Neither avian salmonella nor the strain found in peanuts is the deadly "bird flu," which passes from birds to humans.

Ornithologist Susan Campbell, of the Weymouth Woods Nature Preserve, said it is most likely that bird deaths since January have been caused by a natural phenomenon.

"The likelihood of seed contamination in this area is not high," she said. "Spread of (avian salmonella) comes from contact with fecal matter."

Campbell advises taking in feeders for a while, to prevent birds from congregating.