As in past years, Delta is involved in about 20 different research projects in 2009; but the diversity of topics continues to grow as we delve into non-traditional topics, such as economics and the application of ALUS, the sophisticated math required to describe population growth in scaup, and the quantification of hunter concerns and preferences regarding wildfowling. Of course, we continue to do work to better understand the ecology of waterfowl as well as studies that specifically evaluate management options aimed at producing more ducks.
If we start our road trip out west we would run into two students working in California. Brian Olsen is a student at University of California, Davis that is evaluating management techniques for moist soil management units. Moist soil units typically are impounded areas that are dried out in the spring or summer so that the soil allows seed producing wetland plants like millets to get established. When these plants are mature and the seasonal wetlands are reflooded it provides a smorgasbord that ducks find irresistible. Brian is evaluating different management strategies for moist soil units. Another student working with Brian’s advisor, Dr. John Eadie at UC, Davis is Kevin Ringleman. Kevin is taking a detailed look at the ecology of nest predation in an effort to understand how the behavior of nest predators affects the likelihood of predation in terms of space and time. Brian examines the nest site selection behavior of individual hens as well as the predation behavior of individual skunks. To monitor skunks, Kevin uses sophisticated GPS radio telemetry units that give exact locations at short intervals of time.
As we travel up the Pacific Flyway our road trip would take us to Anne Mini, doctoral project site in the Willamette Valley. Anne has the opportunity to examine how body size for a range of Canada and Cackling Geese influences their winter foraging ecology. This is of ecological interest as well as providing practical value for managing goose depredation issues. In this case, the geese are occasionally damaging sod farms with high intensity grazing.
Much farther north up in central Alaska is where we find one of Brandt Meixell’s study sites. Although Brandt is a Ph.D. student at University of Minnesota, he is looking at the pathogenicity of avian influenza viruses in wild birds from Alaska to the prairies. Previous studies of pathogenicity have been conducted on captive birds where there is little environmental variation nor do birds experience the stresses of scarce food, predators, or migration. Brandt will study various types of influenza on multiple species of ducks and look at body condition survival and reproduction.
Our next stop is the campus of Utah State University where we would find Beth Ross at her field site – namely behind a high powered computer. Beth is analyzing scaup population models to find the most appropriate characterization of how this population changes. Unfortunately, the trend in population change in the last two decades has been pretty consistently negative. The combination of declining numbers and very limited data other than the annual count information means that it is especially difficult to set scaup harvest rates so that we are confident that hunting isn’t contributing to the population decline. Beth is using the most advanced analytical techniques that wildlife biologists have at their disposal to try and produce a reliable growth model for scaup.
Continuing with Scaup research we next visit the Centennial Valley of Montana, which is where Kyle Cutting, a student at Montana State University is conducting a more traditional field study. Kyle’s radio marks Scaup that he captured at the start of the nesting season so that he can document the impact of a female’s body condition on her probability of nesting and her seasonal productivity. There is some consensus among waterfowl biologists that Scaup productivity has declined; detailed research like Kyle’s work will shed light on what is causing the lower production.
Parkland habitat in central Saskatchewan is our next destination. Parklands, unlike prairie habitat, historically had a mix of both grassland dominated habitats with a scattering of wooded areas. At some of John Dassow’s township-sized research plots the amount of bush habitat is impressive. In recent years we have come to view parkland habitat as fairly different that grassland habitats – the good news is that it tends to be more predictably wet in parkland habitat. The bad news is that predation rates tend to be higher, so nest success in these potentially productive sites can really be pretty poor. John’s study was designed to test the efficacy of predator trapping in parkland habitats. First year results were impressive – with nearly a 5 fold increase in nest success on the trapped sites. John’s second year produced very different results. John switched the treatment (predator reduction) and control (no trapping) sites, and found that all areas had poor nest success. John, who spends his winter months at Southern Illinois University, is coming back to Saskatchewan for a third field season to try and get a more clear answer about the efficacy of trapping. Perhaps trapping predators will prove to be less effective in parkland habitat than grassland habitats, or perhaps the 2008 results were an effect of the particular landscape that limited the number of traps to less than half of what we use in North Dakota on a similar sized block.
If we travel east to Manitoba we would encounter another evaluation study of trapping in the parklands. This study is centered at Delta historic Minnedosa Field Station, where recent graduate students have reported abysmal predation rates – in several years upland ducks had less than 1% nest success. This study is planned as a long term effort that will assess nest success for both dabbling ducks and diving ducks – Minnedosa pothole country used to be some of the best Canvasback breeding habitat in the world. In addition to assessing nest success we will monitor pair numbers over a series of years to see if predator reduction in habitat that is underutilized by ducks will lead to an increase in the density of ducks over a series of years. Joe Lancaster is heading the team for this predator evaluation work.
A three hour drive south of the Minnedosa site puts you squarely in the prairie grasslands of eastern North Dakota where Delta has a series of students finishing a very large scale evaluation of predator management. Matt Pieron is working out of Louisiana State University and for three years directed a nest searching effort that located more than 8,500 nests on the trap and control blocks. As in prior studies, the nests on trapped blocks had significantly higher nest success than on non-trapped blocks – 64% on trapped block and 42% on non-trapped. However, the real focus of Matt’s dissertation work was to see if pair densities were higher on trapped blocks as a result of the elevated nest success. The answer was a resounding “no.”
Courtney Amundson is a student working on the same sites in collaboration with Matt, though Courtney’s work is focused on brood survival. Courtney, who works out of the University of Minnesota with Dr. Todd Arnold spend a couple of years tracking Mallard broods with radio telemetry and discovered that, unlike prior research in Saskatchewan, predator reduction in North Dakota was not increasing duckling survival. Worse yet, Courtney’s estimates of brood survival on trap (19% survival) and non-trapped sites (22% survival) are among the lowest recorded for any mallard study. Matt and Courtney combined their impressive data on Mallards and produced an estimate of the impact of predator reduction on overall productivity. It appears that in landscapes with abundant grass and reduced predators – red fox populations were decimated by the one-two punch of a disease called Sarcoptic mange and by increasing coyotes – that trapping is not producing large numbers of fledged young. Nest success rates are high, mallards persistently renest, so they close that gap between nest success on trap and control blocks, and Courtney’s finding suggest that brood survival is low and unchanged by trapping.
Matt and Courtney’s findings strongly influenced Delta’s experimental predator program. This spring Delta selected (with much-appreciated technical assistance from the US Fish and Wildlife Service) all new sites for trapping efforts in North Dakota. Our new trapping sites are blocks of habitat where wetlands are abundant but cover is very scarce, so we expect low nest success. Moreover, we are also attempting a supplemental trapping effort aimed specifically at mink, which are the most important cause of duckling predation. As you would expect from a research-based organization, these changes in the predator program call for a new phase of predator evaluation work. Starting this year, we will begin to assess the efficacy of trapping predators on this very different habitat configuration that occurs in parts of eastern North Dakota. With the declining CRP acreage, we fear that many more landscapes in the US will have low grass and may be good candidates for intensive predator management, so the timing of this work is very appropriate.
Laura Beaudoin is a Ph.D. student from the University of Guelph (Ontario) that is in her final field season working on the former predator treatment blocks. Recall that Matt Pieron found that pair numbers were not increasing over a series of years, even though nest success on trapped and non-trapped blocks was exceptionally high. So the question is what was happening to the young ducks that were being produced? To answer this question Laura undertook some ground breaking research to monitor the movements of young ducks as they achieve flight and become independent of mom. Much of Laura work was focused on fall survival and movements, which is a segment of the life-history that has been virtually ignored for 50 years. Laura also uses some sophisticated radio packages that have an internal clock that turned off the radio in late November and didn’t turn on the radio again until March. This saved the battery so that Laura could determine whether the young females homes to North Dakota or dispersed. Laura’s first-year answer was remarkable – over 60 % of the radioed bird came back to near their marking site, but then they all soon dispersed to locations outside of North Dakota.
A final student working on the old trapped blocks is Tim Kimmel. Tim’s work builds on the research of Matt and Courtney by using the set of banded Mallards - now well over 1000 hens. These females have been monitored enough that they all have an individual nesting history. Tim’s research goal is to document the consistency of nesting parameters over years – so he monitors traits like exact nest location, the date of nesting, egg size, and number of eggs laid for females that we have repeatedly caught at their nest. Tim also relates all of these characters along with nest success to the age of the female.
After that long visit to North Dakota we travel south a few hundred miles to Nick Docken’s (South Dakota State University) study of predator management. Nick is evaluating trapping efficacy in South Dakota, but unlike prior predator work, this trapping effort is in prime Ring-necked Pheasant habitat, so the goal is to assess duck and pheasant nest success. The duck results so far have mirrored most other predator studies – with trapped site s having higher success (32%) than non-trapped sites (21%). However, Pheasants have proved to be a lot harder to study because of the difficulties of finding nests. The preliminary finding suggest that nest success is pretty low, partially due to high nest abandonment, but that trapping substantially improves nest success.
If we stay in the Central Flyway, then our next stop takes us to New Mexico, where Dustin Taylor from Oklahoma State University is doing research on Pintails wintering at the Bosque del Apache National Wildlife Refuge. This refuge is one of the few remaining spectacular wetlands in the Rio Grande river drainage and has immense concentrations of wintering ducks, geese and Sandhill Cranes. These birds help attract nearly 200,000 visitors to the refuge during the winter, which leads managers to question whether the human visitors are negatively impacting Pintails. Dustin’s job is to answer that question using behavioral observations and by measuring stress hormones in captured pintails.
Now we skip east to the Mississippi Flyway for a stop in the Gulf Coast marshes of south-western Louisiana. This is where Bruce Davis from Louisiana State University is studying the non-migratory Mottled Ducks. The problem with year-round residents is that Bruce rarely gets a break in his work schedule. During the late summer he works with biologists from the Louisiana Department of Wildlife and Fisheries to capture flightless females during the annual wing molt. Some of these females are radio marked and become the birds he tracks for the next year. Bruce’s study is focused on habitat use, but he is also collecting data on survival and movements. As you may recall, Louisiana was buffeted by two major hurricanes in 2008 (Gustav and Ike). Perhaps unsurprisingly, the Mottled Ducks simply moved inland during the tidal surges that came with the storms; they experienced no mortalities that Bruce could link to the storms.
Another Ph.D. student from LSU is Luke Laborde. Luke is working in the field of human dimensions and is focusing his research on duck hunters rather than on ducks. Specifically, Luke is looking at hunter participation and satisfaction and relating measures of hunter activity and perceptions of satisfaction with regulations, duck numbers, access issues, alternative demands on time and money, social climate, and a long list of other suspected deterrents to waterfowl hunting. The impetus for this work is the decline in duck hunters and the concern that creates for the future of duck hunting, duck populations, and the protection of waterfowl habitat. Luke’s study will cover hunters ranging over the entire Mississippi Flyway.
Up at the north end of the flyway we would encounter Sarah Thompson from the University of Minnesota. Sarah is evaluating the impact of woody vegetation on duck nest success in western Minnesota. Sarah’s work entails searching for duck nests on many different Waterfowl Production Areas, some where woody vegetation physically was removed and others where woody vegetation remains. Sarah’s first-year results suggest that removal of woody vegetation to restore prairie areas does improve duck nest success.
As we move toward the Atlantic Flyway we encounter Rob Baden from the University of Western Ontario who is studying the winter ecology of Canvasbacks and Redheads wintering on Lake St. Clair an the Detroit and St. Clair Rivers in Ontario, but just a stone throw east of Detroit. No, this isn’t traditional wintering area, but increasing numbers of birds that concentrated in this aquatic system during fall migration are selecting to stay all winter. Lake St. Clair is known for large bed of wild celery, but the birds that elect to spend the winter face risks of starvation during inclement weather. Rob is going to try and assess the benefits and the risk of short-stopping at this migratory area.
About 100 miles east of Rob’s study site is the Ontario demonstration site for ALUS – Applied Land Use Services – in Norfolk County, which is just north of the legendary Long Point. Two students, Jessica Rosenburg and Paul Guerra, from Guelph University, are undertaking research to help understand how to best implement this revolutionary habitat program. Jessica is an economics policy student looking at the role of social capital and trust in delivering conservation programs on farmlands under ALUS. Her studies will investigate the capacity of communities to plan, manage and deliver conservation programs. She will identify factors that contribute to and detract from building social capital for conservation in rural communities.
Paul is also an economics policy student, but his project examines the economic concept of "club goods" where a number of interests in a specific set of goods combine their efforts to create a market for those goods, in the case of ALUS, the goods are ducks and other environmental goods such as clean air, clean water, habitat for species at risk and others. Paul will review all current policies and programs that may be integrated on the ground in support of ALUS in Norfolk County. The idea is to effectively combine all of the policies and potential resources available to ALUS in Norfolk County.
As you can see, this is a trip through some of the most important breeding, migration and winter habitat in North America. Yes, it would be easier if all Delta funded graduate students worked at one field station. However, we encourage student to focus of important research questions and that means we have to go to where the most important habitats are located. You can also see that the diversity of questions continues to expand. While Delta research remains committed to two simple goals – promoting ducks and waterfowl hunting – the means to achieve those goals calls for a diverse and active research program.
