The first message came two weeks ago. “I found six dead redpolls in my back yard,” it read. In quick succession, that message was followed by others. Three dead redpolls. A dying pine siskin. More dead and dying redpolls.
I hadn’t seen this kind of report since we had many house finch deaths from avian conjunctivitis a decade ago. The human form is a mild infection, and easily treated. The avian form is much more serious: crusts form over the birds’ eyes and death is a common result. That disease caused a striking decline in the population of those finches.
Not this time, however. One concerned bird feeder kept the dead birds frozen and sent them to Ken Roblee at our local Department of Environmental Conservation. He then forwarded the birds for necropsy to the DEC state office in Delmar to have the cause identified.
The report by state pathologist Joe Okoniewski came back: salmonella poisoning. It also noted that similar poisoning of redpolls and siskins has been recorded across the state this winter.
I contacted my friend Marilyn Pecoraro-O’Connell, proprietor of the Wild Birds Unlimited store in Blasdell, who provided me a number of sources related to this problem. These included University of Oregon professor Dan Gleason and the U.S. Geological Survey’s National Wildlife Health Center. I summarize here.
• This problem is national in scope. Siskins, in particular, are dying in the West, where they are more common.
• Salmonella is the most common of four main diseases that affect feeder birds. The others are trichomoniasis, aspergillosis and avian pox.
• Other birds are affected but less often, among them evening grosbeak, house sparrow, cowbird, cardinal and goldfinch. Salmonella occasionally occurs in house and purple finches but is rare among other songbirds.
• The problem is not in the seed you have purchased. The disease is communicated through birds’ feces.
• You can usually identify sick birds. They are less alert and active, feed less and often cower on a feeder, reluctant to fly. An infected bird dies quickly as bacteria spreads through its body and forms abscesses in its gut.
• Although this is a serious problem, it does not mean that feeding birds is bad. You do need, however, to feed intelligently in order to enjoy and support healthy wild birds.
• Any time you work at your feeders, you should sanitize your hands. Salmonella can be transmitted to humans and is the most common type of “food poisoning.”
Follow these suggestions to avoid disease problems at your feeders:
• Provide ample feeder space. The stress created by crowding may make birds more vulnerable to disease. Do this by adding feeders and spreading them widely apart.
• Keep your feeder area clear of waste food and droppings.
• Provide safe feeders without sharp points or edges and replace wooden feeders that are difficult to sanitize with plastic or metal feeders.
• Use fewer platform or tray feeders.
• Disinfect your feeders. Use one part liquid chlorine household bleach in nine parts of tepid water – a 10 percent solution. Immerse an empty, cleaned feeder completely for two to three minutes, then air dry. Once or twice a month usually suffices, but do so weekly during this epidemic.
• Discard any food that smells musty, is wet, looks moldy or has fungus growing on it. Then disinfect the container and scoop you used.
• Keep rodents out of stored food.
• Don’t wait to act until you see sick or dead birds.
• Take all your feeders down for a few days if you find dead birds nearby.
Bird feeding gives you pleasurable opportunities to see birds at close range and, especially during ice storms, may save their lives. So don’t give up; just follow these suggestions.