BPOP: Breeding Population of Ducks Down 11 Percent from Last Year
Posted on 07/12/2004
BISMARCK, ND— Last spring a dozen US Fish and Wildlife Service pilot biologists revved their planes’ engines in preparation for next year’s 50th anniversary of the world’s largest wildlife inventory, the spring waterfowl breeding population and habitat survey.
What they found was a significant decline in May ponds and an 11 percent drop in the breeding population of ducks across the traditional survey area that includes Alberta, Saskatchewan, Manitoba, Alaska, Yukon Territory, the Dakotas and western Montana.
The spring breeding population of mallards dropped to 7.4 million from last year’s 7.9 million, a one-year decline of seven percent and one percent below the long-term average. The spring mallard population is the lowest it’s been since 1994, the year the most recent drought ended.
The total duck population dropped to 32 million from 2003’s 36 million, a decline of 11 percent and three percent below the long-term average.
Prospects for a good year of production don’t appear favorable given a 24 percent drop in the May pond count across the traditional survey area. Hardest hit by dry conditions were prairie Alberta (down 43 percent from last year and 30 percent from the long-term average), prairie Saskatchewan (down 32 percent from a year ago and 26 percent from the LTA) and the eastern Dakotas (down 32 percent from 2003 and 20 percent long term). Over-all May ponds across the prairie pothole region (PPR) were down 24 from last year and 19 percent from the long-term average.
“We got a mixed bag of news this spring,” says Rob Olson, president of Delta Waterfowl. “Many areas of the prairies were very dry when the spring survey was conducted, and apparently some of the early-nesting birds like mallards and pintails over-flew the breeding grounds and headed north into Canada’s bush country. History has taught us that when ducks over-fly the prairies, production is typically poor.
“The good news is that water conditions have improved across portions of the region since the spring survey was conducted,” Olson says. “Parts of North and South Dakota and southern Canada received good rainfall in May and June, parts of southern Manitoba are very wet and conditions are pretty good across the extreme southern portions of Saskatchewan. Alberta remains very dry.
“That moisture could have been good for late-nesting species like gadwall and blue-winged teal, and it might have prompted those mallards and pintails that did settle on the prairies to re-nest. Improved wetland conditions also should enhance brood survival.
“And let’s face it,” Olson says, “we’ll take moisture whenever we can get it.
“On the other hand, it’s May ponds that drive production on the prairies. Given moisture conditions in May and the number of birds that over-flew the breeding grounds, and it would appear that production this year will be down.”
Ron Reynolds of Fish and Wildlife’s Habitat and Population Evaluation Team (HAPET) in Bismarck agrees with Olson’s assessment. “Obviously any moisture helps,” says Reynolds, “but as far as pulling us out of a bad start, I doubt the late rains will have a huge impact on productivity.
“We should see some production across the northern tier of counties in North Dakota, which attracted quite a few ducks because they were wet early,” Reynolds says. “But we don’t expect much production in the southern part of the state or across South Dakota, which was really dry.”
Among the other popular species inventoried, gadwall numbers stood at 2.6 million, up two percent from 2003 and 56 percent over their long-term average; wigeon dropped to just under 2 million, a decline of 22 percent from last year and down 25 percent long term; green-winged teal were at 2.5 million, down eight percent from 2003 and up 33 percent long term; blue-winged teal slipped 26 percent to 4 million, down 10 percent from the LTA; northern shoveler was at 2.8 million, down 22 percent from 2003 and up 32 percent from long term; northern pintail dropped to 2.2 million, down 15 percent from last year and off 48 percent long-term; redhead dropped five percent from last year to 605,000, three percent below long-term; canvasback was up 11 percent to 617,000, 10 percent above the long-term average, and scaup rose two percent to 3.8 million, which is 27 percent below the LTA.
One of the dozen flyway biologists who flew the breeding grounds last spring is John Solberg, a 25-year veteran with USFWS who in 19 years as a pilot-biologist has flown half a million miles.
Flying his Cessna 185 at 100 miles an hour just 150 feet off the ground, Solberg notes the species and sex of ducks observed on his side of the plane—“mallards a pair, pintails two males”—while an observer in the passenger seat records ducks and counts and types wetlands by size and permanence.
Their observations are captured by an onboard computer that’s interfaced with a Global Positioning System (GPS) unit that marries the information about ducks and wetlands with the exact coordinates.
Teams of ground observers then follow up the flights, searching 18-mile segments of the transects and counting birds that may have been missed by the flight crew. The ground crew’s observations are used to arrive at a “correction factor” which is used to produce the most accurate possible numbers.
It’s a far cry from primitive data-collecting techniques employed by the pioneers of the spring survey like Art Hawkins, Lyle Sowls and Walt Crissy. Those legendary scientists identified the transects that, according to Solberg, are basically the same as those being flown today.
Each spring the pilots fly some 45,000 miles across roughly two million square miles covering the Dakotas, western Montana, Alaska, the Yukon and the prairie provinces of Alberta, Saskatchewan and Manitoba. Next spring the Service will officially celebrate the 50th anniversary of the spring survey.
Unfortunately, the Service recently announced that several other long-time surveys have been discontinued due to lack of funding. One of those is the July survey which records July ponds and brood indexes across the breeding grounds.
“The spring breeding population and habitat survey is one of the great success stories in wildlife management,” says Olson. “But it’s a shame that we’re losing the July survey, because it provides brood data to help assess production, and measures July ponds which are important to the broods.”