It's not great news for Minnesota duck hunters. The state's breeding mallard population index this spring was down 21 percent from last year, and was 17 percent below the 10-year average, based on the Department of Natural Resources spring waterfowl survey released Monday. The blue-winged teal index also was down almost 50 percent. The survey results for other ducks combined, such as wood ducks, ring-necked ducks, gadwalls, northern shovelers, canvasbacks and redheads, was 135,000, was down 29 percent. There was some good news: Canada goose numbers were up. Officials said the unusual spring makes it difficult to interpret this spring's duck counts. "It was a very unusual spring for weather, wetland conditions and breeding waterfowl," Steve Cordts, DNR waterfowl specialist, said in a news release. "We had record warm temperatures and early ice-out by late March, so ducks moved into the state early. But wetland conditions were extremely dry at that time." Conditions have improved dramatically since then, but much of the precipitation came after ducks had already begun nesting or moved through the state, Cordts said. Those, and other factors, make it more difficult than usual to interpret this year's population indices, he said. Here's more from the DNR release: The same waterfowl survey has been conducted each May since 1968 to provide an annual index of breeding duck abundance. The survey covers 40 percent of the state, which includes much of the best remaining duck breeding habitat in Minnesota. A DNR waterfowl biologist and pilot count all waterfowl and wetlands along established survey routes by flying low-level aerial surveys from a fixed-wing plane. The survey is timed to begin in early May to coincide with peak nesting activity of mallards. The U. S. Fish and Wildlife Service provides ground crews that also count waterfowl along some of the same survey routes. This data is then used to correct for birds not seen by the aerial crew. The goal in the DNR's Duck Recovery Plan is to attract and hold a breeding population of 1 million ducks. "Although the survey does not estimate total duck populations in the state, the decline in this year's spring duck population index indicates we're likely well below our goal," said Dennis Simon, DNR Wildlife Section chief. "The DNR remains committed to our long-term habitat goals of improving breeding and migration habitat for waterfowl in the state." Canada geese The Canada goose population is estimated by a separate helicopter survey conducted in April. This year's estimated goose population was 434,000, which was higher than last year's estimate of 370,000. "Because of the early spring, Canada geese nested early," Cordts said. "Production appears to be excellent, with large numbers of goose broods across the state. This has resulted in increased reports of agricultural damage by geese this year." The Canada goose hunting season established by the DNR in recent years is open for 107 days, the maximum number of days allowed. "We may have to explore additional options in the future in order to address the large Canada goose population," Cordts said. The Minnesota waterfowl report can be viewed online at www.mndnr.gov/hunting/waterfowl. DNR will announce this fall's waterfowl hunting regulations in early August.