These results underscored the important role of spring staging wetlands in building nutrient reserves. However, we don’t really know how scaup migration patterns responded to these habitat changes or whether poor body condition was or is experienced by sufficient numbers of scaup to have continental impacts on the population. Many birds may have shifted to alternate migration routes   and staging areas. Currently, researchers using satellite-tracking devices are studying the movements of scaup through the Mississippi Flyway to better understand migration patterns. You can follow   these transmitter-fitted birds by visiting www.ducks.org/Conservation/Scaup ResearchProject.

There is also debate about whether birds affected by poor-quality habitats are able to compensate by acquiring nutrients from habitats farther north, or whether they just do not breed. Limited studies from the boreal breeding grounds found that birds arriving at several northern locations were in relatively good condition and that there were no apparent differences from historic estimates of body mass, timing of nest initiation, or clutch size. These results suggest that compensation is possible or that too few birds are affected to detect a difference. However, the influence of reduced body condition on a female’s ability to breed, or even migrate north, is unknown.

Breeding Grounds

While the focus was initially on wintering and staging areas, researchers also examined the boreal forest and discovered an alarming trend. Wetlands in the northern boreal forest of both Alaska and Siberia were disappearing—quite literally being drained away in some cases. These wetland losses have been linked to climate change, which is thought to be melting the permafrost seal. This seal holds water in many wetlands and lakes, and without it, water drains into the soil over time. Indeed, at several important scaup breeding areas in Alaska, 25 percent of wetlands have disappeared since 1950, mostly in the last 20 years. This habitat change has not been investigated in the heartland of scaup breeding in Canada, but could be occurring there as well.

Some wetlands aren’t disappearing because of climate change but are warming up earlier in the spring and getting hotter in summer. Research suggests this change has caused shifts in the types and numbers of aquatic invertebrates in these wetlands, including a reduction in those that female scaup and ducklings prefer to eat. The potential implications are that less food and a poorer quality diet could cause ducklings to grow slower and could delay wing feather development of post-breeding females and young, reducing survival on the southward migration.

So where does all this research leave us? Certainly, we have advanced our knowledge of scaup, but we still have many more questions. It is unlikely that contaminants are affecting scaup to the degree once speculated, although the topic needs further investigation, particularly as it relates to winter survival of birds in contaminated habitats like the Great Lakes. Habitat change on spring staging areas in the upper Midwest probably affects a portion of the scaup migrating north to breed each year. But the severity of those effects and the number of birds affected by these changes remain elusive. Studies from the boreal forest have also uncovered changes in habitat and food availability. These discoveries could have impacts on both female survival and productivity, but direct links between these changes and scaup survival or reproduction still need to be clearly identified.

Attendees at the 2006 workshop identified seven priority issues ranging from continued work in the boreal forest to evaluating scaup harvest management. Participants also recognized that while significant progress had been made, much work lies ahead, and the best way to maintain momentum was to create a new Scaup Action Team under the North American Waterfowl Management Plan. The mission of the Scaup Action Team is to ensure that new knowledge about scaup helps inform management, that scaup research is coordinated, and that greater attention is paid to supporting scaup research, management, and conservation actions.

It may be too late to fully understand what caused the more than 20-year decline of scaup, so our emphasis has now shifted to understanding why they are not recovering, which may or may not be due to the same reasons. However, the waterfowl community is banding together for progress. And with time, wisdom, and persistence, our concerted efforts could return us to the days when scaup were more abundant.

Dr. Jean-Michel DeVink is an environmental scientist with Jacques Whitford, a private consulting firm in Fredericton, New Brunswick.
Dr. Stuart Slattery is a research scientist with DU’s Institute for Wetland and Waterfowl Research in Stonewall, Manitoba.