If you're concerned that your rain garden or ornamental pond could become a breeding ground for disease-carrying mosquitoes, the Metropolitan Mosquito Control District recommends calling a staff expert.
Jim Stark, the district's public affairs coordinator, recommends that people call if they find recently dead birds that have no apparent trauma -- the birds may have died of West Nile virus.
West Nile encephalitis, a potentially fatal disease for humans, first appeared in the United States in 1999 and has spread across the country. People get it from infected mosquito bites. Mosquitoes get it from feeding on infected birds.
In 2002, the United States had 4,156 human cases of West Nile virus and 284 deaths, according to the Centers for Disease Control Web site. Stark said Minnesota had 48 cases and no deaths in 2002 and 149 cases and four deaths in 2003.
People need to make sure their rain gardens don't have standing water longer than four or five days, he said. Problems occur when silt and leaves slow drainage and create mosquito-breeding areas. Ornamental ponds won't breed mosquitoes if a fountain or aerator keeps water moving or if they are kept clean and free of vegetation or debris.
District staff will collect dead birds, such as blue jays and crows, and send them to the Minnesota Department of Health for testing. Call if the bird has no other apparent signs of injury and if it appears to have died recently. The virus lasts in the bird's system only a day or two.
To report a dead bird or for questions about ponds and rain gardens, call the district at 651-545-9149.