A record number of ducks will be winging their way south this fall and winter, a new survey by the U.S. Fish and Wildlife Service suggests.

That survey estimates a total duck population of as many as 48.6 million, sharply higher than the 45.6 million last year.

And that increase comes at a time when habitat conditions are declining.

The survey covers nearly 2 million square miles of waterfowl habitat across the United States and Canada.

What they found:

* Mallards: 10.6 million, a 15 percent increase over 2011 and 39 percent higher than the long-term average of 7.6 million.

* Gadwall: 3.6 million, 10 percent higher than the 2011 estimate of 3.3 million. That's 96 percent above the long-term average.

* American wigeon: 2.2 million, up only 3 percent from 2011, and still 17 percent below the long-term average.

* Green-winged teal: 3.5 million, a 20 percent increase from 2011's 2.9 million.

* Blue-winged teal: 9.2 million, a 3 percent increase from last year and a whopping 94 increase above the long-term average.

* Northern shovelers: 5 million, 8 percent more than 2011, and 111 percent above their long-term average.

* Northern pintail: 3.5 million, down 22 percent from 2011 and 14 percent below the long-term average.

* Redhead: 1.3 million, down 6 percent from last year's 1.4 million but still nearly 90 percent higher than the long-term average.

* Canvasback: 800,000 birds, up 10 percent form last year and up 33 percent from the long-term average.

* Lesser and greater scaup: 5.2 million, which was 21 percent above the 2011 estimate and 4 percent above the long-term average.

In the eastern survey area, the estimated abundance for American black duck, green-winged teal and merganser populations showed an increase from 2011 estimates in this area. The survey showed declines in abundance for mallards, goldeneyes, and ring-necked ducks..

Habitat conditions observed across the survey areas during the survey were characterized by average to below-average moisture, especially in the southern portions; due primarily to a mild winter and an early spring.

The estimate of ponds for the north-central U.S. was 1.7 million, which was 49 percent below the 2011 estimate of 3.2 million.

Significant decreases in wetland numbers and conditions occurred in the U.S. prairies during 2012. Nearly all of the north-central U.S. habitat was rated as good to excellent in 2011; however, only the habitat in the coteau region of North and South Dakota was rated as good in 2012. No areas were rated as excellent this year.

Drastic wetland declines in western South Dakota and Montana resulted in mostly poor to fair habitat conditions.