DU issues Mississippi Flyway report

Total breeding ducks down 11 percent, but still 15 percent above LTA

Last month, the U.S. Fish and Wildlife Service released its annual waterfowl breeding population estimates, indicating duck numbers had held steady and were similar to last year.

Total populations were estimated at 48.4 million breeding ducks, which is 38 percent above the 1955-2015 average, but lower than last year’s estimate of 49.5 million birds.

Although large numbers of ducks and geese returned to the breeding grounds this spring, wetland conditions were initially less favorable for waterfowl production across much of the Prairie Pothole Region.

May ponds—the unit of measure for wetland abundance on the prairies—decreased 21 percent in 2016, from almost 6.3 million ponds in 2015 to approximately 5 million ponds this spring. The total May pond count remained near the long-term average, however, largely due to carryover water stored in wetland basins from the previous year.

Faced with drier conditions on the prairies, many waterfowl continued migrating north to breeding areas in the Boreal Forest and Arctic.

“In light of the dry conditions that were observed during the survey period, it is reassuring to see that the breeding population counts were little changed from last year’s,” DU Chief Scientist Dr. Scott Yaich said. “What’s not reflected in the report is that the outlook for waterfowl production improved significantly after the surveys were completed. On some key waterfowl breeding areas in Prairie Canada, heavy June and July rains greatly improved wetland conditions. This likely benefited brood-rearing and the success of late-nesting species, and also gave a boost to overall production through renesting by early-nesting species.

“Watching the changes in habitat conditions over the spring and summer this year underscores the importance of two things: First, we must simply accept that habitat and duck populations are going to vary over time. They always have, and they always will. Second, that’s why we need to keep a steady hand on the course of our conservation efforts. Our job is to continually make deposits into the habitat bank account so that when precipitation and other conditions are right, the ducks will do the job they do so well, which is to produce more birds and provide us all with a nice return on our investments.”

The following report from DU on the Mississippi Flyway is based on data from the government and biologists in the field.

The majority of Mississippi Flyway waterfowl are raised on the prairies of the United States and Canada, as well as in the Western Boreal Forest, southern and central Ontario, and the Great Lakes states. In southern Manitoba, ample carryover water and timely spring rains resulted in a 17 percent increase in May pond numbers, which were near the long-term average overall. Total breeding ducks in this region were down 11 percent this spring, but remained 15 percent above the long-term average.

DU Canada biologist Lena Vanden Elsen reports that late spring and summer weather improved prospects for waterfowl production in southern Manitoba this year.

“The southwestern portion of the province received several significant precipitation events beginning in mid-June and continuing into July,” Vanden Elsen said. “Grassland cover for nesting waterfowl was lush, and haying operations were delayed because of the rain. In late July, our field staff were still observing large numbers of broods of various ages, indicating a strong breeding effort among both early- and late-nesting species. Brood survival was also expected to be good this year, as wetlands and upland vegetation were in good condition.”

The waterfowl production outlook was variable in neighboring Ontario, which is an important breeding ground for the Mississippi and Atlantic Flyways.

“In June, the temperature warmed up across Ontario, and for much of southern and central Ontario, an extended period of drought began,” DU Canada biologist David McLachlin said. “Conversely, reports indicated that wetland conditions were more favorable across northern Ontario, with abundant precipitation on the Hudson Bay coast to more variable amounts across the Boreal zone. While drought across the south limited seasonal wetland habitat for breeding pairs, many larger brood-rearing wetlands have withstood the lack of precipitation. In the north, field reports indicate that habitat conditions were generally favorable for breeding pairs and broods.”

Ducks and geese raised in the Great Lakes states make an important contribution to waterfowl populations locally and throughout the eastern Mississippi Flyway.

In Minnesota, total duck numbers were up 47 percent this spring and were 25 percent above the long-term average. In Michigan and Wisconsin, duck populations were largely unchanged from the previous year’s estimates and their respective long-term averages. As in southern Ontario, dry spring and summer weather likely impacted waterfowl production in the Great Lakes states in 2016.

“Abnormally dry conditions persisted throughout much of the brood-rearing period across a substantial portion of the Great Lakes region,” Dr. John Coluccy, director of conservation planning in DU’s Great Lakes/Atlantic Region, reported. “These conditions likely hampered brood survival and renesting efforts to some degree.”

This was a good year for most Mississippi Flyway goose populations. Weather conditions in the central Arctic were generally favorable for breeding waterfowl, and average to above-average production of lesser snow, Ross’s, and white-fronted geese is expected this year. Excellent production was reported among giant Canada geese, while inclement weather on northern breeding areas may have adversely affected breeding success for Mississippi Flyway Interior Population Canada geese, which include birds from the Southern James Bay, Mississippi Valley, and Eastern Prairie populations.

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