Midwest Fish & Wildlife Conference 2019

AUTHORS: Zack Loken, University of Wisconsin at Stevens Point; Jacob Straub, University of Wisconsin at Stevens Point; Rachel Schultz, State University of New York at Brockport

ABSTRACT: The Glacial Habitat Restoration Area (GHRA) is a 558,879-acre restoration zone in east-central Wisconsin. The GHRA was designed to enhance wildlife habitat, especially for waterbirds, through wetland restorations. We observed and counted all waterbirds on wetland basins from April – May of 2017 and 2018 using fixed location focal scans. We categorized study wetlands into 3 groups based on hydrologic modification: scrape; scrape plus wetlands with ditch plug, ditch-fill, and/or tile break; and scrape plus berm and/or berm with a water control structure. Two reference groups were included: Waterfowl Production Areas and unmodified sites without basins. Wetland plant communities were categorized following the Natural Heritage Inventory database, mapped using aerial imagery, and field checked for accuracy. After plant communities had been digitized, habitat heterogeneity was assessed within each wetland property using an interspersion-juxtaposition index (IJI). Greater values of IJI indicated that community types were more evenly dispersed throughout the wetland than areas with large blocks of similar vegetation. Wetlands with diverse habitat types distributed throughout their basins may be more attractive to waterfowl than those with a homogenous composition. Analysis of year-one data found that habitat heterogeneity, of the 38 properties, ranged from 17.7 to 85.5 and differed among hydrologic modification categories (P = 0.04). Data from year two is currently undergoing analysis. Our results will be used to assess landscape scale factors that might influence the use of restored wetlands by wetland-dependent bird species.

AUTHORS: Benjamin R. Williams, Thomas J. Benson – Illinois Natural History Survey, University of Illinois Urbana-Champaign; Aaron P. Yetter, Joseph D. Lancaster – Forbes Biological Station, Illinois Natural History Survey, University of Illinois; Heath M. Hagy, U.S. Fish and Wildlife Service

ABSTRACT: Spring migration is an important and often under-studied period of the waterfowl annual cycle. Stopover sites along migration routes contain habitats and resources required by waterfowl to rest and refuel before continuing north to the breeding grounds.  The Wabash River Valley (WRV) in southeastern Illinois provides habitat for over 500,000 dabbling ducks each spring.  Despite the heavy use of this region, information regarding stopover duration and habitat use of waterfowl is lacking.  Stopover duration, or the length of time an individual spends in a distinct region, is an important metric for waterfowl managers to consider while planning for the needs and required resources of migrating birds.  Stopover duration for mallards (Anas platyrhynchos) and green-winged teal (Anas crecca) was approximately 17 days (95% CI:  12.6–22.9 days).  This is shorter than current estimates used by conservation planners and may shift objectives.  Additionally, mallards and green-winged teal used emergent and woody wetland habitat at rates highly disproportional to the availability of those habitats on the landscape.  Both species tended to avoid sites with greater amounts of agriculture in the surrounding landscape, while sites surrounded by greater amounts of open water, upland forest, and upland grassland were more likely to be used.  There was also a considerable amount of use in areas under conservation easements, suggesting the importance of these easements in waterfowl management.  All of this information will help land managers and conservation planners direct funding to the most important habitats in the WRV and ensure sufficient resources for waterfowl utilizing the region each spring.

AUTHORS: K. Kali Rush, Jacob N. Straub, Matt Palumbo – University of Wisconsin-Stevens Point

ABSTRACT: The Wood Duck (Aix sponsa) is a focal species in the Upper Mississippi River and Great Lakes Region Joint Venture’s (JV) waterfowl habitat conservation strategy. The JV estimates the regional breeding population is 145,000 less than their population objective. In Wisconsin, the wood duck is the second most abundant breeding duck, but their population is declining like other Great Lakes States populations. To better understand population vital rates that could be related to the observed declines in abundance, our objectives were to quantify hen survival and hen and brood habitat use during the breeding season. We captured female wood ducks using decoy and nest box traps from 7 April to 5 July 2017 and 22 April to 20 May 2018, prior to nest initiation, and fitted hens with VHF radio transmitters (ATS 3930, 7g). Hen survival was estimated and compared between breeding status and among predominant habitat type used including emergent wetlands, scrub-shrub, and forested wetlands. We also monitored individuals and nest sites to estimate breeding propensity, clutch size, and nest success. In 2017 and 2018, 43 female wood ducks were captured. We used a known-fate model in program R to model hen survival as a function of breeding status (i.e. attempted nest or did not attempt nest) and habitat types. This approach yielded heretofore unavailable hen and brood survival estimates for breeding wood ducks in the state of Wisconsin to improve our knowledge of how wood duck populations are changing. 

AUTHORS: Samuel T. Klimas, Western Illinois University; Joshua M. Osborn, Auburn University; Heath M. Hagy, US Fish & Wildlife Service; Christopher N. Jacques, Western Illinois University; Joseph D. Lancaster, Illinois Natural History Survey; Sean E. Jenkins, Western Illinois University; and Aaron P. Yetter, Illinois Natural History Survey

ABSTRACT: The Illinois River Valley (IRV) provides critical stopover habitat for migrating waterfowl during spring and autumn. Because spring migration is an important time for waterfowl as they enhance body condition in preparation for the breeding grounds, the UMRGLR Joint Venture relies on the IRV and other migratory focal areas in Illinois to protect, maintain, enhance, and restore more than 80,000 ha of wetland habitats for waterfowl. Green-winged teal (GWTE; Anas crecca) usually rank in the top 4 species in the Illinois duck harvest, and primarily consume natural foods during migration, often selecting for seeds and invertebrates over agricultural grains. In order to provide current information on wetland habitat needs for GWTE to wetland and natural resource managers, we experimentally collected foraging GWTE during the spring in the IRV from the confluence of the Illinois and Mississippi rivers extending north to Hennepin, Illinois, during springs 2016–2018. We removed upper digestive tracts and estimated food availability (benthic and nektonic samples) at foraging sites to evaluate food use and 4^th order selection. We analyzed diets from the upper gastrointestinal (GI) tract (proventriculus and esophagus), as well as gizzards. Further, we performed proximate analysis on the teal carcasses to analyze body condition in relation to diet. We will discuss overall food use and selection by GWTE, as well as preferences of plant and invertebrate taxa in comparison with food availability.

AUTHORS: Matthew D. Palumbo, Jacob N. Straub – University of Wisconsin-Stevens Point

ABSTRACT: The goals of the 2012 North American Waterfowl Management Plan target a combination of biological and social objectives that are prioritized regionally through Joint Venture (JV) partnerships. The Upper Mississippi River and Great Lakes (UMRGLR) JV developed a decision support tool (DST) to assist in implementing these objectives. The DST is based on six spatially explicit model-based maps, each representing a biological or social objective weighted by input from regional decision makers. The DST depicts areas of relative value to meet the combined six objectives and therefore identifies areas for regional managers to target conservation for waterfowl and people. In 1992 Wisconsin Department of Natural Resources developed their own state-based conservation plan to achieve waterfowl population and habitat objectives.  This ‘WI Plan’ was based on a spatial hierarchy of priority regions, areas, and townships that were delineated from estimated waterfowl densities and habitat, geo-political boundaries, and expert opinion. Since 1992 managers have been working to implement conservation practices based on this system. However much has changed since this time thus, our objective was to revise the 92 WI Plan and provide an updated spatially-explicit tool to drive waterfowl habitat conservation efforts in the upcoming decades. Using the framework of UMRGLR JV, we developed six updated model-based maps representing waterfowl and human objectives specific to Wisconsin.  These maps have allowed WI conservation managers to visualize how conservation practices would be prioritized under various ranks of biological and social values. The WI DST will assist state managers with redistributing priority regions based on eco-physiographic boundaries and quantitative ranking based on the underlying biological and social data of the tool. The DST of UMRGL JV and WI demonstrate the value of incorporating spatio-temporal variation of biological and social data for conservation managers to prioritize practices.