The Fish and Wildlife Service says breeding duck numbers across U.S. prairies and in Canada and Alaska rose 11 percent from a year ago, to 45.6 million birds.

Last year's figure was 40.8 million.

The 2011 count is 35 percent higher than the long-term average, which dates to the 1950s.

Total ponds counted in prairie Canada and in the north-central U.S. were 8.1 million, 22 percent higher than the 6.7 million ponds counted in 2010.

Duck production and therefore the size of the fall flight usually vary with pond abundance.

According to the service:

• Estimated mallard abundance was 9.2 million birds, a nine percent increase from the 2010 estimate of 8.4 million birds.

• Blue-winged teal estimated abundance was a record 8.9 million, which was 41 percent above the 2010 estimate of 6.3 million, and 91 percent above the long-term average.

• The northern pintail estimate of 4.4 million was 26 percent above the 2010 estimate of 3.5 million, and similar to the long-term average.

• Estimated abundance of American wigeon was 14 percent below the 2010 estimate and 20 percent below the long-term average.

• The combined (lesser and greater) scaup estimate of 4.3 million was similar to that of 2010 and 15 percent below the long-term average of 5.1 million. The canvasback estimate of 700,000 was similar to the 2010 estimate and 21 percent above the long-term average.

In the eastern survey area, estimated mallard abundance was 400,000 birds, similar to the 2010 estimate and the long-term average. Estimated black duck abundance was 400,000 birds, which was similar to 2010, but 13 percent below the long-term average. Habitat conditions in the eastern survey area were good to excellent; in particular, conditions in Ontario and southern Quebec improved from 2010 to 2011.

The service uses the annual survey to establish its waterfowl conservation programs and regulatory frameworks for waterfowl hunting season lengths, dates, and bag limits.