Welcome to the interactive web schedule for the 2019 Midwest Fish & Wildlife Conference! Please note, this event has passed. To return to the main Conference website, go to: www.midwestfw.org.
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CONFERENCE SCHEDULE UPDATES & CHANGES: As a result of the prolonged government shutdown, we experienced a number of cancellations and changes to the schedule. Cancellations and changes are listed here (as of January 26, 2019).
AUTHORS: Sarah Saunders, National Audubon Society; Kristin Hall, Minnesota Department of Natural Resources; Nina Hill, University of Minnesota; Nicole Michel, National Audubon Society
ABSTRACT: Intensifying wetland stressors in the Great Lakes region of the United States have hastened the need to identify local and landscape-scale habitat characteristics important to marsh-dependent wildlife to inform conservation prioritizations. The optimal spatial scale for assessing species-habitat relationships is not always apparent, but may affect inference about wetland use and suitability. We developed occupancy and abundance models, while accounting for imperfect detection, for nine marshbird species breeding in Minnesota. We evaluated species-specific wetland cover associations at three spatial scales (12.6 ha, 50.3 ha, and 4000 ha), quantified sensitivity to anthropogenic disturbance (developed land and agriculture), and evaluated ecoregional variation in marshbird occupancy and abundance. Emergent vegetation was positively correlated with occupancy rates of 89% of species, emphasizing the conservation value of this land cover type for sustaining breeding marshbird populations in the state. Agriculture was negatively associated with occupancy for three species, and positively associated for three other species, especially at the landscape scale. Development was negatively related to occupancy for five species, but positively related for Marsh Wren. Occupancy of all species was highest in the Prairie Pothole ecoregion, and Pied-billed Grebe and Sora were most abundant at wetlands in this region. Restoration efforts targeted within the western portion of the state are most likely to boost marshbird populations and use conservation resources effectively. Future applications of our modeling framework at broader spatial extents will contribute to the conservation of marshbirds in a region where rates of wetland loss and degradation are high.
AUTHORS: Maureen L. Hurd, Thomas J. Benson – Illinois Natural History Survey and Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign; Michael P. Ward, Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign
ABSTRACT: The Chimney Swift (Chaetura pelagica) is a bird species of conservation concern in Illinois and one of many aerial insectivores experiencing population declines across North America. While causes of declines are unknown, habitat availability and changes in insect populations are likely contributing factors. Chimney Swifts historically nested in tree cavities, but switched to nesting primarily in masonry chimneys as North American settlements expanded. With the growing trends of chimney caps and gas/electric heating, available chimneys are disappearing, and the loss of available nest sites may be driving Chimney Swift declines. Like other aerial insectivores, Chimney Swifts may also provide valuable pest control services and action may be needed to maintain this benefit. To investigate potential causes of declines in Illinois, we examined the influence of habitat and landscape factors on Chimney Swift abundance. We conducted surveys for swifts in 126 municipalities throughout Illinois and recorded the number of uncapped masonry chimneys at each survey point. We used these data along with landscape-level data such as composition of land cover surrounding points, areal extent of municipality, and age distribution of buildings. We found that 97% of municipalities were occupied by Chimney Swifts, but abundance varied considerably. Swifts were detected at 72.5% of survey points. Chimney Swift abundance was most heavily influenced by the number of uncapped masonry chimneys at survey points. Our results suggest that although Chimney Swifts are still widespread, contemporary building practices will continue to drive population declines and management should focus on approaches for providing and preserving suitable nesting sites.
AUTHORS: Therin Bradshaw, Western Illinois University/Illinois Natural History Survey - Forbes Biological Station; Cheyenne Beach, Western Illinois University; Heath Hagy, US Fish & Wildlife Service; Christopher Jacques, Western Illinois University; Abigail Blake-Bradshaw, University of Illinois at Urbana-Champaign, Joseph Lancaster, Illinois Natural History Survey - Forbes Biological Station
ABSTRACT: Marsh birds are an understudied guild of migratory birds of conservation concern that can be valuable indicators of wetland health and may benefit from wetland management for waterfowl. I assessed marsh bird occupancy of wetlands across Illinois to better understand how natural wetland characteristics, impoundment management for waterfowl, and surrounding landscape characteristics influence marsh bird occupancy of wetlands. During late spring and early summer 2015–2017, I surveyed marsh birds three times annually at focal sites (passive or active management for waterfowl), random sites (emergent, pond, or lake polygons from the National Wetland Inventory), and Critical Trends Assessment Program (CTAP) sites (wetlands from the Illinois Natural History Survey’s CTAP). Marsh bird occupancy was greatest during my first survey period (Ψ=0.71, SE=0.11), followed by my second (Ψ=0.55, SE=0.14) and third survey periods (Ψ=0.39, SE=0.14). Focal (Ψ=0.74, SE= 0.09) sites had greater occupancy than random (Ψ=0.62, SE=0.08) or CTAP sites (Ψ=0.32, SE=0.11). Occupancy also varied by wetland complexity (greatest in the large levels of complexity [Ψ= 0.99, SE= 0.02]), waterfowl management intensity (greatest at an intermediate level of management [Ψ=0.39, SE=0.178]), percent wetland area inundated (greatest in large area of inundation [Ψ=0.74, SE=0.089]), and percent cover of persistent emergent vegetation (greatest with large percent persistent emergent vegetation cover [Ψ=0.81, SE=0.148]). Across species and marsh bird groups, detection probability decreased with ordinal date, for every week delay in marsh bird survey detection declined 7.1% (SE=2.1). Our results suggest that waterfowl habitat management positively influence marsh bird occupancy. Occupancy increased with management practices that were less intensive and focused on keeping water on the landscape with little disturbance to encourage habitat characteristics such as high habitat complexity, large area inundation and high percent cover of dense persistent emergent vegetation.
AUTHORS: Bradley F. Blackwell, Morgan B. Pfeiffer, Travis L. DeVault, Thomas W. Seamans – USDA/APHIS/WS National Wildlife Research Center
ABSTRACT: Bird movements, particularly during migration, provide information on timing and species composition relative to climate change and population dynamics. Movement data have been traditionally gleaned from observers for the North American Breeding Bird Survey (BBS) and Audubon Christmas Bird Count, and via band returns. More recently, weather and avian radars are contributing movement data (not necessarily specie-specific), and citizen science is providing observation data via Ebird. An untapped and publically available source of species-specific movement data is the U.S. Federal Aviation Administration’s Wildlife Strike Database. From 1990–2016, 183,296 wildlife-aircraft collisions (strikes) were reported (179,542 in USA and 3,754 strikes by US-registered aircraft in foreign countries) to the FAA. Birds compose approximately 96% of reported strikes, and aircraft “sample” intensively a broad spectrum of altitudes and geography seasonally. Approximately 529 bird species have been struck over the 27-year period. Our purpose is to introduce this novel source of avian survey data as a potential compliment to current information on avian movements. As such, we will discuss how strike data are collected, identified, reported, and inherent biases. We will provide trends for March through July over the last ten years in reported strikes for six species (including a warbler, blackbird, shorebird, waterfowl, wading bird, and raptor) struck in the Mississippi Flyway and species relative strike frequency per the respective year. We will relate these trends to the known spring migration movement timing and Ebird population trends for each species for the same region and period.
AUTHORS: Nicole Hengst, The Ohio State University; James Hansen, The Ohio State University; Brendan Shirkey, Winous Point Marsh Conservancy; John Simpson, Winous Point Marsh Conservancy; Robert Gates, The Ohio State University
ABSTRACT: Secretive marsh bird populations are threatened by habitat loss throughout their ranges. In Ohio, Virginia rails (Rallus limicola) and soras (Porzana carolina) are species of concern and legally harvested. Very little work has been conducted to understand movements and habitat selection by Virginia rails and soras in coastal wetlands of the western Lake Erie basin. Managed wetlands are an important source of rail habitat in Ohio, yet little is known about how manipulation of water levels to produce food and cover for waterfowl affects migrating and breeding rails. Virginia rails and soras were captured and fitted with VHF radio-transmitters and tracked daily during March-September, 2016-2018. Twenty-seven percent of radio-marked rails migrated or dispersed from the study site within 1-2 days of capture in May-August. Mean home range sizes were 6.51 and 3.67 ha (SE = 1.40, n = 57 and SE = 0.95, n = 7) for Virginia rails and soras, respectively. Of the 166 radio-marked rails that remained at the study site at least one day after capture, 138 used only one impoundment unit at the study site. This allowed us to examine movement patterns of Virginia rails and soras in response to water level changes during 2016-2018. Vegetation surveys were conducted in 2018 to compare differences in habitat characteristics between locations of radio-marked rails and random points and to identify wetland habitat characteristics that rails select for as water levels change. Vegetation surveys were conducted weekly at individual radio-locations and at the end of the growing season within home ranges of radio-marked rails. Twenty-two percent of the weekly surveys indicated rails using areas dominated by cattail (Typha spp.) with water cover <40% and medium interspersion. This work will provide additional understanding of rail ecology and aid in better informed wetland management for rail species in northern Ohio.
AUTHORS: Brian Washburn, USDA Wildlife Services; Adam Phillips, USDA Wildlife Services; Siddhartha Majumdar, University of Illinois at Urbana-Champaign; David Mayer, University of Illinois at Urbana-Champaign; Ryan M. Swearingin, USDA Wildlife Services; Edwin Herricks, University of Illinois at Urbana-Champaign; Travis L. Guerrant, USDA Wildlife Services; Scott Beckerman, USDA Wildlife Services; Craig Pullins, USDA Wildlife Services
ABSTRACT: Avian radar technologies have the potential to serve an important role in the quantification of bird movements and determining patterns of bird use in areas where human–wildlife conflicts might occur (e.g., airports, wind energy facilities). However, capabilities and limitations of these technologies are relatively unknown and ground-truthing studies are needed to help wildlife managers understand the biological meaning of radar information. We evaluated the efficacy of 3 X-band marine radar sensors for tracking birds and flocks of birds observed on the airfield at Chicago’s O’Hare International Airport, USA, during March 2011−November 2012. Specific information regarding field observations of birds or flocks was used to determine how frequently the 3 radar sensors provided corresponding tracks of these avian targets. In addition, various factors were examined to determine if they had any influence on the frequency of correspondence between visual observations and radar tracks. Of the 972 sightings of individual birds (49%) or flocks of birds (51%) by observers on the airfield that had the potential to be observed by the radar, 141 (15%) were tracked by at least one radar sensor. All confirmed tracks of bird/flocks were ≤4.8 km from these radars. Among the 3 radar sensors, larger-bodied bird species, bird/flocks flying at higher altitudes, and bird/flocks closer to the radars increased the ability of those units to track avian targets. This study provides new information regarding the performance of radar systems for tracking birds on the airfield of one of the largest and busiest airports in the world.
AUTHORS: Ross P. McLean, University of Wisconsin-Stevens Point
ABSTRACT: Whooping Cranes (WHCR) are federally endangered and in 2001, a reintroduction effort was initiated at Necedah National Wildlife Refuge (NNWR) in Wisconsin to establish an Eastern Migratory Population (EMP). However, despite seventeen years of management, recruitment remains low. Greater Sandhill Cranes (SACR, Antigone canadensis tabida) are biologically similar to WHCRs and have similar breeding ecology. We studied colt survival for both crane species at NNWR to determine if low recruitment is unique to the Eastern Migratory Population (EMP) of WHCRs, or an issue for both North American crane species in the initial introductory breeding grounds of the EMP. Additionally, we lowered water levels in some wetland impoundments to better mimic the natural annual water cycle. This management action was part of an effort to increase wetland and forage access for wading birds during summer months. Our objectives were to determine (1) if summer drawdowns and reduced wetland water levels increase survival of WHCR and SACR colts compared to cranes reared in or near impoundments with full water levels, and (2) differences in overall colt survival rates between species. We hypothesized that (1) WHCR would use the drawdown areas more than available wetlands with higher water levels, and (2) that colt survival would be higher in lower water wetlands due to increased mobility and access to prey. We placed VHF transmitters on adults and colts of both species to collect colt survival status and family group locations every day during the 2017-2018 field seasons. Analyses are ongoing, but many of the fledged colts were raised in areas with lower water. We will discuss implications for crane management in the Midwest. <a href="applewebdata://63650BC7-DDE7-47CB-BF71-58A32F69113E#_msoanchor_1"></a>
AUTHORS: Matthew B. Shumar, Ohio Bird Conservation Initiative
ABSTRACT: Many species of birds migrate at night, guided in part by starfields and lunar paths. However, artificial lighting is becoming increasingly abundant on the landscape. This source of pollution has the ability to disrupt migratory cues and cause substantial mortality; birds attracted to bright lighting often fatally collide with buildings, and it is estimated that between 365 and 988 million birds are killed by collisions each year in the United States. Collaborative conservation programs designed to address bird-building collisions have been successful in a number of cities across North America—including Toronto, Chicago, and New York—by combining elements of public outreach, conservation, and research in a campaign to reduce the dangers of nighttime lighting for migrating birds. With support from a wide range of partners, including state wildlife agencies, local government, universities, and non-profit conservation organizations, Ohio’s first “Lights Out” campaign was launched in Columbus in 2012. In 2013, we initiated a study to assess the relative influence of light intensity and building height on collision rates. Results strongly suggested that minimizing lighting on tall buildings would effectively reduce collision rates. In recent years, this partnership has expanded “Lights Out” into a statewide network, with focused efforts in Ohio’s major urban centers. To date, regional branches of Ohio Lights Out have been established in seven cities. The magnitude of this conservation issue is likely greater than currently understood (e.g., more than 2,100 dead and injured birds were salvaged by volunteers in Cleveland during 2017 alone), and each city presents unique social and political challenges. There is great potential for programs such as “Lights Out,” but success will ultimately depend on cooperation among wildlife agencies, academic institutions, wildlife rehabilitators, natural history museums, building owners, city officials, and the general public.
AUTHORS: Sirena Lao, Oklahoma State University; Abigail W. Anderson, University of Minnesota; Robert B. Blair, University of Minnesota; Joanna W. Eckles, Audubon Minnesota; Reed J. Turner, Audubon Minnesota; Scott R. Loss, Oklahoma State University
ABSTRACT: Collisions with buildings are a major source of human-caused bird mortality, especially for migratory species. Most bird-building collision studies have assessed building or landscape-related factors that correlate with mortality, such as glass area, the proximity of glass to vegetation, and the amount of surrounding greenspace. However, very little research has investigated factors causing temporal variation in bird-building collisions, and there is no published research that rigorously quantifies the influence of weather conditions on collision rates of migrating birds. During spring and fall migration, we hypothesize that more collisions occur under two scenarios: when conditions for migration are favorable (e.g., clear conditions, favorable tailwinds, and/or after the passage of a fall cold front), and hence more birds are moving; and when visibility is poor (e.g., fog, storms, or low cloud ceiling), causing migrating birds to potentially “fall out” in urban areas where they may be attracted to artificial light at night. To assess the effect of weather on collisions, we used counts from daily carcass surveys conducted during spring and fall migration of 2017 and 2018 at 21 buildings in downtown Minneapolis, Minnesota, and we compiled hourly weather data from the Minneapolis-Saint Paul weather station for each night from sunset to sunrise. We found that variables associated with favorable migration conditions, including wind direction and temperature, had the largest effect on collision mortality. We also found that weather conditions during certain times of night are especially important, and that collisions can be associated with weather conditions from one or two days prior to the night they occur. Understanding the effect of specific weather conditions on bird-building collisions will allow for the use of weather forecasts to better predict when major collision events will occur, and will therefore allow preemptive actions to be taken to reduce collision mortality.
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: Jonathan Rice, Luke DeGroote, Matt Webb, Jake Slyder – Carnegie Museum of Natural History
ABSTRACT: Throughout the spring (April-May) and fall (Sept-Aug) migrations of 2014 – 2016, citizen scientists searched for birds that had collided with buildings in downtown Pittsburgh, PA, USA. These volunteers spent 965 hours searching an area encompassing 217.7 ha comprised of skyscrapers, low commercial buildings, apartment buildings, and city parks. Volunteers found 705 dead or injured birds, 218 in the spring and 487 in the fall. We delineated building sides for all buildings with collisions (n=278), and for randomly selected buildings without collisions (n=65). We quantified physical characteristics of the building and adjacent land cover using GIS and field visits (presences and extent of overhangs, percentage of windows, reflectivity of windows, rugosity, and presence of landscaping). Bird-window collisions were more frequent at larger, structurally complex buildings with nearby vegetative cover. Our results demonstrate that not all buildings are equally dangerous for birds. Furthermore, future bird-window collisions could be mitigated if architects and urban planners design buildings with less glass, fewer alcoves, and less nearby vegetation.
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: Andrew W. Jones, Cleveland Museum of Natural History; Tim Jasinski, Lake Erie Nature & Science Center; Courtney L. Brennan, Cleveland Museum of Natural History; Sylvie F. Crowell, Cleveland Museum of Natural History; Gary Fowler, Lake Erie Nature & Science Center; Laura Gooch, Cleveland Museum of Natural History; Moira Meehan, Ohio Wesleyan University; Stephanie Secic, Ohio State University
ABSTRACT: In 2017, we initiated a collaboration among six organizations to monitor bird-building collisions in downtown Cleveland, Ohio. Field monitoring is carried out entirely by volunteers, starting at dawn on every day in spring and fall migration. Social media has been a key tool to recruit new volunteers as well as to coordinate daily monitoring schedules. During daily surveys, injured birds are placed in paper bags and then transported to Lake Erie Nature & Science Center for rehabilitation. Most injuries are related to cranial swelling. We report several approaches that have been successful in rehabilitating species that do not typically recover well in captivity, including American Woodcock. Birds are then banded before release. Birds that are found dead, or die during rehabilitation, are frozen and later prepared as museum research specimens at the Cleveland Museum of Natural History. In Fall 2017, over 1,800 collisions were detected in downtown Cleveland. Over 1,200 of these collisions were fatal. We reviewed collision data, comparing collision sites to the adjacent landscape, finding that building facades that face large green spaces are responsible for significantly larger numbers of collisions. We compared collision rates, per species, to local abundances from citizen science efforts, finding that collision rates are not proportional to abundance.
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<sup>th</sup> 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: Lucas W. DeGroote, Jonathan Rice – Carnegie Museum of Natural History
ABSTRACT: It is often asserted that “half” or “many” birds that hit windows and live to fly away will later die of internal injuries. Yet our knowledge of these injuries is limited to a small number of birds that were sacrificed to compare their injuries to birds that did not survive a window collision. Only recently are we able to track small post-collision migrants over large distances thanks to a collaborative array of automated receiving stations (Motus Wildlife Tracking System) that are able to detect VHF transmitters operating on the same frequency (i.e. nanotags). We utilized the Motus WTS and nanotags to study the long-term effects of bird-window collision on 29 migrant landbirds found by citizen science volunteers in Pittsburgh and Cleveland the spring of 2017. We will compare their survival and migratory behavior to 21 birds captured via mist nets at Presque Isle Bird Observatory (NW PA) and Powdermill Avian Research Center (SW PA). In addition, we will utilize data collected by rehabilitators to quantify short term survival of birds found by citizen scientists. With this data we will gain insight not only on the long-term effects of bird-window collisions on individuals but also population level consequences that as of yet have been unquantified through traditional citizen science based collision monitoring programs.
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.
AUTHORS: Benjamin Winger, University of Michigan; Brian Weeks, University of Michigan; David Willard, The Field Museum
ABSTRACT: Global warming is hypothesized to cause reductions in animal body size. Migratory birds are particularly vulnerable to change because they breed at high latitudes where temperatures are changing most rapidly, their morphologies are constrained by the demands of migration, and they are dependent on fluctuating seasonal resources and climatic conditions throughout their annual cycles. We analyzed morphological change for 52 species of migratory birds from 1978-2016, using measurements of 70,000 specimens that died from building collisions during migratory passage through Chicago, IL. Across species, we found a consistent decline in body size and consistent increase in wing length. Body size declines are linked to increasing summer temperatures on the breeding grounds: years with high summer temperature yielded birds with smaller body size. Increases in wing length are driven by selection during the migratory period, which we hypothesize is due to compensatory selection for efficient flight to maintain migratory journeys in the face of shrinking body size. The species composition of the Chicago collision data we analyzed also yielded insights into the relevance of avian social behavior for understanding the negative impacts of artificial light on birds during nocturnal migration.
AUTHORS: Ryan Butryn, Taber Allison – American Wind Wildlife Institute
ABSTRACT: The American Wind Wildlife Institute (AWWI) has developed a database of post-construction fatality monitoring data containing hundreds of studies, many of which have been unavailable for analysis. We present the results from our first analysis of more than 200 studies at 140 projects from across the U.S. The size of our data set enables us to evaluate fatality rates and incident data on a biologically relevant regional scale (e.g., avian migration flyways, bird conservation regions). Bird and bat fatalities have been observed at almost all wind facilities; however, the species composition and number of fatalities varies greatly among these facilities. Our results show substantial differences in regional variation in bird and bat fatality estimates indicating different underlying patterns affecting collision risk in these two groups. We also found bird and bat species assemblages detected by post construction surveys also varied substantially by region. We will provide examples of how increased data availability provided by AWWI can help reduce uncertainties in risk and impact assessment and inform focused and effective fatality reduction measures.
AUTHORS: Megan Seymour, U.S. Fish & Wildlife Service
ABSTRACT: Bird and bat collisions at wind turbines are well documented and of concern to wildlife management agencies and the public. Data is typically collected by consultants funded by the wind project owner, and is often deemed to be proprietary even though it is collected under state or federal collection permits. This presentation will discuss the how some mortality data can be accessed, what state and federal agencies can share, and what the concerns are with making data public. When collision data is not shared, our ability to conserve birds and bats proactively is limited, however given available information we can infer certain mortality patterns and risk factors. These, along with management implications will be discussed.
AUTHORS: Donald Bauman, Ken Mauer, Kimberly Kaufman – Black Swamp Bird Observatory
ABSTRACT: Current Ohio law is gravely deficient in providing any review of the biological resource impacts caused by the construction of single commercial-size wind turbines or small-scale multi-turbine wind farms. This oversight is especially problematic when such turbines are constructed in environmentally sensitive areas, such as the southern shore of Lake Erie and the major migratory flyways associated with the Lake. As pressure for renewable energy increases it is likely that exploitation of this large regulatory deficiency will increasingly be utilized to the detriment of Ohio’s public trust biological resources. As such projects are often not publicized in advance of construction and it is very difficult to raise concerns about them in a meaningful way, a systematic means of controlling such wind turbine projects appeared to be necessary. Accordingly, the Black Swamp Bird Observatory and its Conservation Committee have developed proposed legislation which would provide a mandatory, scientifically-based review process to be implemented in defined geographic areas for construction of commercial-size wind turbines falling below the current 5MW Ohio Power Siting Board review threshold. Favorable reaction to the proposal has been received from interested legislators and key Ohio government agencies.
AUTHORS: Matthew Palumbo, University of Wisconsin-Stevens Point; Jacob Straub, University of Wisconsin-Stevens Point, David Luukkonen, Michigan State University; John Coluccy, Ducks Unlimited
ABSTRACT: Abstract: Applied scientific research has been an underpinning of sound waterfowl and wetland conservation for decades. The Lower Great Lakes (LGL), especially wetland and adjacent upland habitats near Lakes Erie, St. Clair, and Ontario, were historically and remain a critical region for waterfowl of the Atlantic and Mississippi Flyways. In fact, hundreds of thousands of waterfowl use this landscape as their primary breeding location and millions use the resources of the region during migration between breeding and wintering areas. Waterfowl managers and researchers in the LGL have strong partnerships and have largely focused efforts in this region on studies that improve understanding of the overall ecology of the species and how management actions can influence these birds. Specifically, the LGL have been the home to seminal studies on waterfowl bioenergetic modeling during spring migration, habitat use and movement for key focal species (e.g., mallards), monitoring and evaluation of diving sea duck distributions on the Great Lakes, studying the potential limiting factors for Great Lakes mallard populations, and influence of weather, wetland availability, and mallard abundance on productivity of Great Lakes mallards. Importantly, these studies have critical linkages to management which have serviced wetlands conservation. Our objective is to synthesize recent research that has improved our understanding of waterfowl ecology and habitat management in the region. Additionally, we will identify future research needs and information gaps to expand waterfowl conservation in the LGL.
Tuesday January 29, 2019 1:20pm - 1:40pm EST
HOPE BALLROOM B
AUTHORS: Brendan Shirkey, WInous Point Marsh Conservancy, Doug Tozier, Bird Studies Canada, Mike Monfils, Michigan Natural Features Inventory
ABSTRACT: Historically, wetland research and management in the lower Great Lakes region has focused on waterfowl given the vested human interest and continental significance of the area as migratory stopover habitat. Recently, additional research focused on secretive marshbirds (e.g., king rails, yellow rails, Virginia rails, sora, least bitterns and American bitters) has gained momentum. Unlike waterfowl populations that are at historically high levels, many secretive marshbird species have experienced significant population decline in the past several decades. However, due to the extremely limited amount of research and secretive nature of many of these bird species, population trend data is lacking and any understanding of habitat associations that might be causing population declines is nonexistent. Many state and federal agencies as well as NGO’s have begun to work collaboratively throughout the Great Lakes region to monitor secretive marshbird populations to fill some of these knowledge gaps. The objectives of this presentation are to: 1) summarize historical marshbird research in the region, 2) highlight recent research that has improved our understanding of secretive marshbirds in the region, and 3) identify future research and information needed to improve our conservation of secretive marshbirds in the lower Great Lakes region. We hope that a continued to effort to understand the life history and habitat associations of secretive marshbirds will ultimately lead to improved habitat management with the potential to benefit waterfowl and simultaneously other wetland-dependent birds and wildlife, including secretive marshbirds.
Tuesday January 29, 2019 1:40pm - 2:00pm EST
HOPE BALLROOM B
AUTHORS: Robert J. Gates, Ohio State University School of Environment and Natural Resources; Mark Shieldcastle, Black Swamp Bird Observatory; David Ewert, American Bird Conservancy; Keith Norris, The Wildlife Society; Tara Baranowski, The Nature Conservancy in Ohio
ABSTRACT: The Lake Erie Marsh region, long recognized as a continentally significant migratory crossroad for waterfowl and other migratory birds with a rich tradition of waterfowl hunting was recognized as a regionally significant migration staging area by the Western Hemisphere Shorebird Reserve Network (WHSRN). Nomination as a WHSRN site was based on counts of 38 shorebird species with minimum known numbers >100,000 birds, compiled from standardized surveys by Black Swamp Bird Observatory during 1993-1999. Repeated surveys of random plots during springs and autumns 2002-2003 revealed shorebird populations that exceeded 100,000 birds on and near just two major marsh complexes (Winous Point Marsh Conservancy and Ottawa National Wildlife Refuge - Magee Marsh Wildlife Area) in the Lake Erie marsh region. Shorebird habitats in the region principally comprise managed impoundments where water levels are manipulated to produce food and cover for waterfowl and create hunting opportunity. Managed marshes were the mainstay for shorebirds during autumn and spring migration in 2002-2003, although estuaries attracted large numbers during seiche events. Surrounding crop fields were used sporadically after precipitation events in spring but were generally too vegetated to attract shorebirds in autumn. Four shorebird species gained 0.28–1.49 g body mass/day with invertebrate biomass densities that ranged from 3.7–12.1 kg/ha during fall migration 2006-2013. Estimated stopover durations were 12-16 days. The Lake Erie marsh region likely merits WHSRN status as an internationally important shorebird area. Results from our studies are used to inform habitat conservation planning and management by state and federal agencies and NGOs in the region. We discuss gaps in our knowledge of migrating shorebirds in the region, including spring vs. fall habitat limitation and energetic carrying capacities of cover types used by migrating shorebirds.
Tuesday January 29, 2019 2:00pm - 2:20pm EST
HOPE BALLROOM B
AUTHORS: Lewis M. Lolya, Gabriel Karns, Stephen N. Matthews –The Ohio State University
ABSTRACT: Early successional bird species have exhibited population declines across Ohio, coinciding with a state-wide loss in young forest and shrub-scrub habitats. Additionally, forest fragmentation and land use conversion has increased with accelerating shale gas development. Pipeline right-of-ways (ROWs), which represent the largest proportion of the shale gas footprint, hold potential for early successional habitat management. This potential has been demonstrated for analogous electric ROWs, but minimal research is available for corridors with underground infrastructure. Our goals are to assess early successional avian response to forest edge-cutback techniques along pipeline ROWs and to understand avian utilization of the pipeline-forest interface. Forest-edge plots (control=11, experimental=12) were established at 10 sites across four counties in Eastern Ohio. Avian point counts, nesting surveys, and vegetation sampling were conducted within each plot. A total of 93 nests of 13 species were monitored. The proportion of failed to fledged nests was 47%, with EATO showing low nest success across sites (Fail=62%). Overall incidence of nest parasitism was higher in edge treatment ROWs (n=9) than in control (n=6). 79 total species were observed across all sites during point counts. Several species showed increased occurrence in ROW plots compared to forest plots ([alpha codes] BHCO, COYE, EATO, FISP, INBU, and NOCA) while others were more prevalent in interior forest (ACFL, OVEN, and REVI). SCTA, EAWP, and ACFL were more prevalent in experimental ROW plots than control. The opposite trend was seen for INBU, potentially due to limited forest regrowth following recent treatments. These results may demonstrate that birds exhibit species-specific selectivity for habitat structure characteristics along pipeline corridors. Although pipeline edges may provide nesting habitat, high occurrence of nest parasitism may indicate the presence of habitat traps. Furthermore, as experimental cutback zones regrow, we hypothesize increased use over time of those edges by shrub-scrub dependent birds.
AUTHORS: David Ewert, American Bird Conservancy; Christopher Tonra, The Ohio State University; Tom Will, U.S. Fish & Wildlife Service
ABSTRACT: The importance of shoreline habitats to landbirds varies with latitude, shoreline substrate, and by season. Metamorphic bluffs with high gradient bathymetry adjacent to boreal forest along Lake Superior provide strikingly different habitat than low gradient, silty shorelines bordered by deciduous forest and forested wetlands on or near Lake Erie shorelines. In turn, these ecologically diverse landscapes result in different land-water interactions that influence how landbirds use shoreline habitat. During stationary periods of the annual cycle, breeding and wintering seasons, species characteristic of wetlands or beach and dune habitats may be relatively common near Great Lakes shorelines. This includes breeding Bank Swallows and Prairie Warblers and wintering Snowy Owls. Indirect effects of a relatively cool and moist nearshore microclimate also influence distribution and relative abundance of species such as the Northern Parula and Canada Warbler.Perhaps the best known use of shoreline habitat by landbirds is that of fall-out areas, especially for passerines, and as migratory corridors for raptors and diurnally migrating passerines that follow Great Lakes shorelines. Additionally, during spring and fall migration at least some Great Lakes shorelines and islands provide important refugia, foraging, and molt-migration areas for landbirds. Conservation efforts for landbirds focused on Great Lakes shorelines have primarily focused on ensuring suitable habitat for migrating landbirds. This includes formation of the Midwest Migration Network, shoreline protection, habitat restoration near Great Lakes shorelines, lights-out programs, especially in major cities, use of bird-friendly glass, and posting of a Great Lakes migration portal that provides guidance for conservation of stopover sites near the Great Lakes.
Tuesday January 29, 2019 2:20pm - 2:40pm EST
HOPE BALLROOM B
AUTHORS: Bryan M. Reiley, T.J. Benson – Illinois Natural History Survey
ABSTRACT: Farmland set aside programs provide important habitat for many wildlife species, yet little information exists regarding how vegetation structure and species respond to conservation practice and site age. This information could provide managers with a guide for how to implement, enhance, and maintain wildlife benefits of these programs. Here, we describe how avian species respond to conservation practice and time since restoration at 172 sites enrolled in the Conservation Reserve Enhancement Program (CREP) in Illinois. To do this we surveyed sites enrolled in four different conservation practices (CPs) within CREP during the breeding seasons of 2012 – 2015 using point counts and vegetation surveys. Vegetation structure and composition varied among CPs with hardwood tree plantings having the greatest amount of understory vegetation, tree and shrub cover, and lowest distance to nearest tree. Conversely, permanent wildlife habitat had the greatest distance to nearest tree, grass cover, and least tree cover. Cover of tree and live vegetation increased and distance to nearest tree decreased with site age and there were conspicuous differences among CPs and site age for these variables and bare ground cover. Avian densities varied among CP types, however only Dickcisselswere significantly greater in sites enrolled as permanent wildlife habitat and, similarly, Bell’s Vireo and Field Sparrow were greater in hardwood tree plantings. Dickcissel density decreased and Field Sparrow density increased as fields aged, but these relationships were not consistent among CP types. Differences among CPs largely resulted from differences in dominance in woody vegetation due to differing management goals. Interestingly, many of our focal species had wider successional tolerances than previously suggested. Our results demonstrate that conservation benefits change over time depending on the starting CP and this information can be used to predict temporal changes in habitat suitability and target conservation benefits toward conservation priority species.
AUTHORS: Christopher M Tonra, School of Environment and Natural Resources, The Ohio State University
ABSTRACT: Increasingly the bias in research towards the stationary portion of the breeding season in animal ecology is being recognized as a barrier to effective conservation. While breeding seasons limit productivity, survival can be most limited outside of the breeding season, and determining limiting factors during these stages can be critical to understanding population dynamics and habitat requirements. This is the case for many populations of migratory birds in the either breed, stage/stopover during migration, or overwinter in the lower Great Lakes. I will present an overview of full annual cycle research on migratory birds in the coastal lower Great Lakes, as well as a more detailed look into several case studies that have advanced our knowledge in this area. This will include an examination of applications for emerging technologies and coordinated monitoring to bridge current information gaps.
Tuesday January 29, 2019 2:40pm - 3:20pm EST
HOPE BALLROOM B
AUTHORS: Gregory J. Soulliere, Mohammed A. Al-Saffar – U.S. Fish and Wildlife Service
ABSTRACT: Targeting conservation to achieve biological objectives for waterfowl and social objectives for people is an emerging priority for bird conservation Joint Ventures implementing the North American Waterfowl Management Plan (NAWMP). To help achieve NAWMP goals in the Upper Mississippi / Great Lakes Joint Venture (JV) region, we integrated objectives related to waterfowl population demography, conservation supporters (hunters and birders), and ecological goods and services important to society and developed a Decision Support Tool (DST). Starting with a table of contemporary conservation issues, we transformed related biological and social data into a family of six spatially explicit model-based maps designed to achieve individual objectives. Output maps were weighted based on discussion with regional decision makers (i.e., the JV Management Board) and then combined, resulting in an aggregate DST to target conservation for waterfowl and people in the JV region. The tool was designed to be flexible and adaptable; objectives and objective weights may be adjusted and subsequent output maps customized depending on stakeholder priorities. Current JV objectives to retain and restore high value waterfowl habitats, while enhancing hunting and birding opportunity and addressing watershed impairments, resulted in a spatially explicit DST with solid emphasis in the lower half of the Great Lakes region.
Tuesday January 29, 2019 3:40pm - 4:00pm EST
HOPE BALLROOM B
AUTHORS: Tim Lyons, University of Nebraska-Lincoln; T.J. Benson, Illinois Natural History Survey; Wade Louis, Illinois Department of Natural Resources; Mike Ward, University of Illinois at Urbana-Champaign; Richard Warner, National Great Rivers Research & Education Center
ABSTRACT: In agriculturally dominated landscapes, the habitat provided by public and private lands is critical for the conservation and management for non-game as well as game species, such as ring-necked pheasants. Management of these areas to increase pheasant populations has focused on increasing field size, the amount of grassland cover in the landscape, or managing vegetation composition within fields, to improve success during the nesting or brood-rearing stages, or the survival of breeding adults. How these actions will impact overall population growth or which stages or habitat features should be prioritized for management is not always clear. We studied how habitat conditions at the field-and landscape-scale influenced the demography of ring-necked pheasants on public and private grasslands in Illinois. Between 2013-2016, we used radio telemetry to track > 200 ring-necked pheasants and quantified the relationship between habitat features at multiple spatial scales, nest success, chick survival, and adult survival. We then used a simulation study to understand how changes to habitat features important to a particular stage ultimately affected population growth. We also examined how predator identity influenced the relationship between adult survival and habitat conditions. We found that several habitat features had contrasting effects among multiple stages and ultimately restricted population growth when management focused on maximizing performance during one stage. Our results also indicate that raptors may be a more important predator of pheasants than is generally recognized, but the risk of predation can be reduced by the management of vegetation within fields. Collectively our work highlights the importance of full life-cycle studies of demography for the effective management of wildlife and suggests that smaller fields, often overlooked in traditional conservation schemes, can play a role in pheasant management when coupled with appropriate management of vegetation within fields.
AUTHORS: Chris Pollentier, Wisconsin Department of Natural Resources; Mike Hardy, University of Wisconsin-Madison; Scott Lutz, University of Wisconsin-Madison; Scott Hull, Wisconsin Department of Natural Resources
ABSTRACT: Eastern wild turkeys (Meleagris gallopavo silvestris) were successfully reintroduced in Wisconsin during the mid-1970s and populations have since expanded beyond their ancestral range throughout the state. Abundance has generally been considered greatest in areas with highly diverse landscapes that include upland woodlands interspersed with agriculture and other open-herbaceous land cover. However, many areas across far northern Wisconsin are comprised of landscapes where the forested area represents > 70% of the land cover. While much research has been focused on areas where populations are generally highest, study of wild turkeys across the far northern reaches of their range in the Upper Midwest and northern Wisconsin has been limited. To better understand wild turkey distribution and habitat relationships across northern Wisconsin, we conducted gobbling call-count surveys along 157 routes from 2013–2017 and instituted a multiseason correlated replicate occupancy modeling approach to link landscape characteristics to patch occupancy. Probability of occupancy was best related to a quadratic function of percentage of open cover (ß = -4.10, SE = 1.07), with probability of occupancy peaking in routes with 30–40% open cover. Probability of colonization was positively associated with the percentage of available agriculture planted in corn (ß = 1.14, SE = 0.42), and also showed a weak negative association with the amount of snow cover (ß = -1.13, SE = 0.62). Our results suggest that even in landscapes where forest cover is pervasive, wild turkeys benefit from the availability of open-herbaceous cover. In addition, corn-crop agriculture serves as an important food resource for wild turkey populations across heavily-forested northern Wisconsin landscapes and influences the probability of colonization into previously unoccupied areas. A better understanding of the distribution of wild turkeys across their northern range will provide much needed information to help guide contemporary management strategies in a post-restoration era.
AUTHORS. Noah P. Horsley; Michael P. Ward; Thomas J. Benson – University of Illinois at Urbana-Champaign
ABSTRACT. The Common Grackle was once one of the most abundant bird species in the Midwest, numbering almost 200 million individuals as recently as 1960 (Sauer et al. 2017). However, steady decline over the past 40 years has reduced this figure by 60%, to roughly 73 million. This makes the Common Grackle one of the most rapidly declining common birds in America (NABCI 2014). Interestingly, the most precipitous decline began around 2000 in the intensely agricultural eastern tallgrass prairie region. This coincided with the mainstream adoption of neonicotinoid seed treatments in U.S. agriculture. Neonicotinoids, currently the most widely used class of insecticides worldwide, have been connected to avian declines in Europe and the United States (Stanton & Clark 2018). We are investigating a possible causal relationship between neonicotinoid seed treatments and Common Grackle decline by studying the nest success and post-fledgling survival of Common Grackles nesting in agricultural landscapes. In our first of two field seasons (2018), we monitored 56 nests across three sites in Champaign County, IL. From these nests, we banded 50 nestlings and tracked the activity and survival of 22 fledglings using hand-held and automated telemetry. Reproductive success will be evaluated by estimating nest success using a logistic exposure model and post-fledgling survival using a known-fate mark-recapture model. We expect the results of this study will serve as a foundation for investigating the role agricultural neonicotinoid use may be playing in Common Grackle decline.
AUTHORS. Alexander Sharp, Kamal Islam – Ball State University
ABSTRACT. The Cerulean Warbler (Setophaga cerulea), a small, neo-tropical migrant, has gained significant attention in recent years as a species that has declined faster than any other North American songbird. Since 2007, we have been monitoring Cerulean Warbler populations within the Morgan-Monroe and Yellowwood state forests of Southern Indiana. Previous studies on cavity nesting and communal cup nesting species suggest that parents will adjust their behavior in response to an avian nest predator, to either avoid detection, or to fend off the predator. These behaviors include mobbing, selective provisioning of nestlings, and increased vigilance and aggression on the nest. Studies suggest that forest fragmentation positively impacts nest predators, and in-turn leads to an increase in nest predation. The objective of this study is to determine if and how Cerulean Warblers change their behavior when a common avian nest predator, Blue Jay (Cyanocitta cristata), is in the vicinity of the nest. In the summer of 2018, we conducted a preliminary study on seven Cerulean Warbler nests found at our study sites. During the observation period, three of the nests were randomly assigned to a control group, and subjected to Ovenbird (Seiurus aurocapilla) vocalizations, and the other four nests were assigned to a treatment group, and subjected to Blue Jay vocalizations. We videotaped parents at the nest during the observation period to analyze their behavior. The results of this preliminary study will be presented. This study is the first to analyze the behavior of an open-cup, canopy nesting species in response to an avian nest predator. Data collected from this study will determine if Cerulean Warblers alter their behavior to avoid detection of their nest, and may help shed some light on the causes of poor nesting success in this species.
AUTHORS. Macayla Greider, College of Natural Resources, University of Wisconsin- Stevens Point, Bellrose Waterfowl Research Center-Forbes Biological Station, Illinois Natural History Survey; Dr. Joseph Lancaster, Bellrose Waterfowl Research Center-Forbes Biological Station, Illinois Natural History Survey; Aaron Yetter, Bellrose Waterfowl Research Center-Forbes Biological Station, Illinois Natural History Survey; Dr. Jacob Straub, College of Natural Resources, University of Wisconsin- Stevens Point
ABSTRACT. Having directly restored, enhanced, and protected greater than 2,700 ha of former floodplain wetlands and associated uplands in the central Illinois River valley, the Nature Conservancy’s Emiquon Preserve is the most substantial floodplain restoration effort in the region to date. The restoration has provided critical nesting habitat for many waterbird species, including species of conservation concern such as Least Bittern, Black-Crowned Night Heron, and Common Gallinule. Since 2013, Forbes Biological Station has conducted nest searches in two distinct wetland vegetation communities, dense emergent and hemi-marsh vegetation. We evaluated nest density, nest success, and nest characteristics of marsh birds during June and July of each year. Nest searches were performed in random plots (0.2 ha) that were generated in ArcGIS and we also found nests incidentally when travelling between plots The addition of a water control structure in summer 2016 increased water management capabilities at Emiquon Preserve and restored river floodplain connectivity. In 2018 managers implemented a drawdown designed to restore moist soil vegetation and provide opportunity to perform levee repairs and this allowed us a unique opportunity to evaluate the effects of the drawdown on waterbird nesting ecology. We will compare data from summer 2018 with all previous monitoring years and compare estimates and characteristics of nest density and survival. This may provide valuable insight into how small habitat manipulations can have a large impact on marshbird breeding strategies. This multi-year research project will continue to provide information to adaptively manage and improve Emiquon Preserve and areas like it using nesting waterbirds as an environmental indicator and sentinel of wetland quality.
AUTHORS. Jeffrey Williams, Benjamin Tjepkes, Joseph Quehl, Brandon Rochefort, Rachel Martin, Dr. Jason Riddle – University of Wisconsin-Stevens Point
ABSTRACT. Ruffed grouse (Bonasa umbellus) are an important game bird in the Great Lakes region. Males perform a unique drumming display atop fallen logs to attract females and maintain their territory. We aim to evaluate drumming log selection in northern Wisconsin as part of a UW-Stevens Point Wildlife Society research project. Auditory drumming surveys were conducted between the months of March and May of 2016 and 2017 to locate used logs. We plan to use the Sound Mapping Tools ArcGIS toolbox to assess where the sound of the drumming is being heard, while accounting for several biotic and abiotic factors. Then we will compare the area of sound propagation of these points to random points throughout the property. Using these methods, we hope to see whether ruffed grouse are selecting drumming logs for their acoustic value. This information will be used to better understand how drumming logs are selected by male ruffed grouse.
AUTHORS. Brandon Connare, Kamal Islam – Ball State University
ABSTRACT. The Cerulean Warbler (Setophaga cerulea), a once common neo-tropical migrant throughout its breeding range, is one of the fastest declining North American wood-warblers. Listed as state-endangered in Indiana and a species of conservation concern across its range, this small songbird has recently been the subject of much research throughout the Eastern United States and Canada. Over the past 10 years, we have been monitoring Cerulean Warbler breeding populations at Yellowwood and Morgan-Monroe state forests in Southern Indiana as part of a larger 100-year project, the Hardwood Ecosystem Experiment. This long term study intends to determine the effect of a variety of forestry practices on local plant and animal communities. Understanding the impacts of forest management practices on Cerulean Warbler populations is reliant upon accurate estimations of the size of home range and territory. Previous research conducted at our study sites and elsewhere mapped Cerulean Warbler territories by following males and recording song-perch locations, which is difficult due to this species’ tendency to stay high up in the forest canopy. For similar reasons, studies examining the size of this species’ home range outside of its defended territory have not been previously conducted. Our objective is to determine the size and seasonal plasticity of Cerulean Warbler territories and home ranges throughout the nesting cycle. In the summer of 2018, we conducted a pilot study on five male Cerulean Warblers using radio-transmitters. We tracked and recorded each bird’s location throughout its home range and territory. We present preliminary results from our study. A better understanding of Cerulean Warbler movements in its territory and home range is vital for the management and conservation of this declining species.
AUTHORS. Margaret Gross, Western Illinois University/Illinois Natural History Survey-Forbes Biological Station; Heath Hagy, U.S. Fish & Wildlife Service; Christopher Jacques, Western Illinois University; John Simpson, Winous Point Marsh Conservancy; Sean Jenkins, Western Illinois University; J. Brian Davis, Mississippi State University; Joseph Lancaster, Illinois Natural History Survey-Forbes Biological Station; Aaron Yetter, Illinois Natural History Survey-Forbes Biological Station
ABSTRACT. Wetland management efforts often target seasonal wetlands because these habitats are considered the most valuable for waterfowl. Understanding the distribution and availability of waterfowl food resources has become especially important amid the loss and degradation of wetland habitats. Waterfowl managers typically estimate the energetic carrying capacity of a wetland by using bioenergetics models to compare energy demand to energy supply. An efficient method for estimating food density utilizes visual indices and predictive equations, though previous attempts to develop predictive equations to estimate aquatic plant biomass are lacking. Furthermore, aquatic vegetation density estimates are lacking for many of the semi-permanent marshes found throughout the Joint Venture, which could cause slight inaccuracies in bioenergetic model parameters. We estimated the energetic carrying capacity of submersed aquatic vegetation for 20 wetland sites within the JV, which was expressed as energetic use days (EUD). Six of the 20 wetland sites were sampled multiple years and the remaining 14 sites were sampled only once during summer 2015–2017. Additionally, we evaluated a rapid assessment technique to estimate submersed aquatic vegetation biomass using percent horizontal coverage of each vegetation species, secchi depth, water depth, and vegetation species specific TMEN estimates. The average energetic carrying capacity among wetland sites and years was 403,521 ± 139, 356 EUD and ranged from 4,114 EUD to 3,761,747 EUD. The submersed aquatic vegetation rapid assessment technique facilitated the development of a predictive index, which was correlated with estimates of submersed aquatic vegetation biomass (kg/ha; R<sup>2</sup><sub>adj</sub> = 0.58, P < 0.0001) and EUD (R<sup>2</sup><sub>adj</sub> = 0.64, P < 0.0001). Our results will be useful to conservation planners for estimating energetic carrying capacities of semi-permanently-flooded marsh habitats, which will aid in projecting impacts of wetland management alternatives (i.e., semi-permanently-flooded marsh versus moist-soil management).
AUTHORS. Therin Bradshaw, Western Illinois University/Illinois Natural History Survey - Forbes Biological Station; Christopher N. Jacques, Western Illinois University; Heath M. Hagy, U.S. Fish and Wildlife Service; Joseph D. Lancaster, Illinois Natural History Survey - Forbes Biological Station; Abigail G. Blake-Bradshaw, University of Illinois at Urbana-Champaign
ABSTRACT. It is widely assumed that waterfowl management activities benefit a variety of wetland dependent birds, but few studies have empirically evaluated those benefits or tradeoffs among multi-species management strategies. In particular, marsh birds are an understudied guild of migratory birds of conservation concern that can be valuable indicators of wetland health and may benefit from wetland management for waterfowl. We assessed marsh bird abundance of wetlands across Illinois to better understand how natural wetland characteristics, impoundment management for waterfowl, and surrounding landscape characteristics influence marsh bird abundance of wetlands. During late spring and early summer 2015–2017, we conducted call-back surveys to assess marsh bird abundance of wetlands with respect to wetland characteristics and management throughout Illinois. We surveyed marsh birds three times annually at focal sites (i.e., passive or active management for waterfowl), random sites (i.e., emergent, pond, or lake polygons from the National Wetland Inventory), and Critical Trends Assessment Program (CTAP) sites (i.e., wetlands from the Illinois Natural History Survey’s CTAP). Marsh bird abundance was positively correlated with percent area cover inundation, greatest at 100% area inundated (abundance = 15.0, SE = 0.52), and lowest at 0% inundated (abundance = 0.99, SE= 0.11) following a logistic curve. Detection probability decreased with ordinal date, for every week delay in marsh bird survey detection declined 10.7% (SE=0.2) at 50 meters. Our results suggest that inundation is related to marsh bird abundance and managers increasing marsh bird abundance on the landscape should hold water at levels suitable for marsh bird nesting creating habitat that provides both nest security and food for foraging.
AUTHORS. Cheyenne R. Beach, Western Illinois University; Rebecca A. Cole, US Geological Survey; Joseph D. Lancaster, Illinois Natural History Survey - Forbes Biological Station; Aaron P. Yetter, Illinois Natural History Survey - Forbes Biological Station; Heath M. Hagy, US Fish and Wildlife Service; Christopher N. Jacques, Western Illinois University
ABSTRACT. During spring and fall migrations throughout the upper Midwest, US, thousands of lesser scaup (Aythya affinis) die from Cyathocotyle bushiensis (Cb) and Sphaeridiotrema spp. (Ss) (Class: Trematoda) intestinal infections after consuming exotic faucet snails (Bithynia tentaculata). Lesser scaup serve as a final host for Cb and Ss while faucet snails serve as the first and second intermediate hosts for the trematodes. As recommended by previous studies, this experimental study will evaluate the potential effects of sub-lethal infections of trematode parasites on the immunological response, body condition, and survival of migrating lesser scaup across the Upper Mississippi River System. Female lesser scaup will be captured at key mid-latitude stopover sites (Pool 19 of the Mississippi River and Emiquon Preserve) and held at Forbes Biological Station, Havana, IL. Faucet snails will be collected by hand from Pool 7 of the Mississippi River and dissected to recover mature Cb and Ss metacercariae. The captive lesser scaup will undergo repeated or single dose trematode infections and will be euthanized 16 days post-infection to gather information that will provide data to evaluate temporal changes in health along a continuum from initial infection to shedding eggs to point of euthanasia. Addressing basic questions related to physiological responses of lesser scaup to infection with trematodes may aid in formulating potential management strategies to minimize co-occurrence of lesser scaup and infected faucet snails.
AUTHORS. Lana Milbern, Stephen Matthews, Ph.D. – The Ohio State University School of Environment and Natural Resources
ABSTRACT. Urbanization can have profound influences shaping patterns of songbird diversity. For many species urbanization poses considerable challenges yet for in many instances urban areas provide important habitat for songbirds, most notably riparian urban areas. With renewed interest to maintain functioning urban forests, understanding the interactions between songbirds and their urban environments is critical to making informed land management decisions.For our study, we chose to focus on the tree-species preferences for foraging and foraging behaviors of songbirds in restored and unrestored sections of urban riparian forests in Columbus, Ohio USA. The goals of our study are to understand how urban songbirds utilize their floristic environment for foraging, identify foraging-related factors, such as food availability, and identify how forest restoration efforts will affect foraging ecology. To answer these questions, we are conducting spot maps, foraging surveys, vegetation surveys, and arthropod counts at urban and rural sites near Columbus, Ohio from May to August in 2018 and 2019. Preliminary data show that urban songbirds most often forage on Acer negundo and Juglans nigra. During Autumn 2018, invasive plants will be removed and two-year-old saplings will be planted in sections of the urban sites. In the spring of 2019, spot maps and foraging surveys will be conducted at these reforestation plots to observe how urban songbirds utilize these saplings for foraging. We hope that this project will help inform urban restoration work in respect to avian conservation.
ABSTRACT: Since its inception in 1990, Partners in Flight (PIF) has taken progressive steps to provide useful range-wide landbird conservation vulnerability assessment at both continental and Bird Conservation Region (BCR) scales. The 2016 Landbird Conservation Plan for Canada and the U.S. introduced new metrics designed to more effectively communicate the urgency of addressing precipitous declines of both range-limited and wide-ranging common species—notably the concept of a "half-life": the forecasted number of years when an abundance that is half the current abundance is reasonably expected to be observed. PIF has also redesigned its website to make it easier to access all of its tools, including its Technical Series, Species Assessment database, Population Estimates database, regional and national conservation plans, and access to its email information and announcement list-serves. Highlighting communication with partners, the revised website provides a platform for exploring and distributing other recent Partners in Flight developments. The Species Assessment, renamed the PIF Avian Conservation Assessment Database (ACAD), now covers all taxa—landbirds, shorebirds, waterbirds, and waterfowl—for over 1600 species from Canada through Panama. The Population Estimates database now provides upper and lower uncertainty bounds around its median U.S./Canada breeding adult population size estimates at state-x-BCR scales. As part of the 2016 Plan, PIF offers recommendations for U.S./Canadian planning unit responsibility for recovering Watch List species and, by incorporating global eBird data, identifies areas of greatest importance for migrants during the non-breeding season to facilitate full life cycle conservation. Finally, a thorough partner review of all regional-scale (BCR) breeding season assessment scores in the U.S. and Canada has just been completed and is now live via the website. The revised regional breeding season assessment provides recommendations reflecting Midwest contributions toward continental bird conservation and identifies regionally important species and regional stewardship responsibilities using a standardized and quantitative methodology.
AUTHORS: Kaitlin Gavenda, Kamal Islam, Clayton Delancey – Ball State University
ABSTRACT: This study aims to test if Northern Saw-whet Owls (Aegolius acadicus) exhibit a preference between two potential habitat types in Indiana, an old growth deciduous forest and a Christmas tree farm, during migration. Previous studies have documented the use of old growth deciduous forest. Christmas tree farms contain the coniferous trees preferred by these owls in their breeding habitat; however, it is an artificial environment that may not contain the cover that Northern Saw-whet Owls favor. This study examines if there are any differences in capture rates between these two habitat types based on season and gender. Two mist-netting stations have been established to monitor fall and spring migration periods: one at Ginn Woods (Ball State University property) in Delaware County, and the other at Whitetail Tree Farm in Henry County, both in Indiana. Each station uses six mist-nets: a line of four nets, with one net on either side of the middle to form a cross. A recording of a Northern Saw-whet Owl call is played at the center of the cross to increase owl capture rates. During last year’s banding, we caught 10 owls at Ginn Woods and 10 owls at Whitetail Tree Farm during the fall, and two more owls at Whitetail Tree Farm during the spring. Of these owls, 9 were hatch year, 6 were second year, and 5 were after second year. Only one male and one unknown sex were captured. We also had two foreign recaptures, one banded in Ontario, 2016, and one banded in Quebec, 2017. Analysis of fall 2018 migration captures will also be included.
AUTHORS: Evalynn M. Trumbo, Michael P. Ward, Jeffrey Brawn – University of Illinois
ABSTRACT: Understanding associations between habitat and the demography of endangered wildlife is essential for effective management, and the age or life-stage of an individual adds complexity to these associations. The Golden-cheeked Warbler (Setophaga chrysoparia; hereafter "warbler"), is an endangered neotropical migrant that breeds only in the contiguous juniper-oak forests in central Texas, of which many studies have evaluated how extensive habitat loss and fragmentation affect adult demography, yet no research has been conducted on post-fledging life stages and their habitat preferences, specifically microhabitat. For birds, the post-fledging stage is critical for sustaining species’ populations and many threats to survival during this life-stage are influenced by habitat type. To understand survival and habitat use, we studied the warbler population at Fort Hood military installation in central Texas. We monitored warbler nests until fledging and deployed one VHF transmitter per nest (n=8 and n=15, for 2017 and 2018, respectively). We tracked fledglings ~4 weeks after fledging. 15 of 23 (65%) of the fledglings survived the observation period. We obtained 1126 vegetation samples measuring various habitat characteristics for the entirety of the study (2017-2018). We compared habitat measurements between fledgling locations and random locations away from the fledgling location. Fledglings appear to select habitat that contains higher canopy cover (86% ± 0.6%, vs. 77% ± 1%). Ground cover, although correlated with canopy cover, differs from non-used habitat (29% ± 0.9%, 37% ±1.05%). Vertical vegetation density in the understory does not differ among used and non-used habitat. Most likely fledglings are selecting for canopy cover since it affords more protection from predators. Using this information for habitat selection will allow managers to implement techniques that promote higher canopy cover in GCWA habitat, hopefully providing a mosaic of necessary traits to support all life stages during the breeding season.
AUTHORS: Anastasia Rahlin, University of Illinois at Urbana-Champaign; Mark Davis, University of Illinois at Urbana-Champaign; Matthew Niemiller, University of Alabama in Huntsville
ABSTRACT: Wetland fragments in Illinois support over 100 bird species, 15 of which are state threatened and endangered. Wetland birds are of particular concern under the Illinois State Wildlife Action Plan due to the lack of information about their population sizes and distributions. Traditional playback methods fall short in elucidating cryptic wetland bird occupancy due to small body sizes, infrequent vocalizations, and unique habitat requirements. In this study, we investigated whether environmental DNA (eDNA) methods could be used to detect multiple rail species, and also hypothesized that taking environmental DNA samples over time would allow us to temporally track rail migration. We collected and filtered water samples from four sites from northern Illinois. We collected and purified DNA from filters using a Qiagen DNeasy kit, and quantified extracts on a Qubit 3.0 fluorometer. We amplified a short fragment of the mitochondrial cytochrome oxidase subunit 1 locus using newly designed degenerate bird primers. We positively detected eDNA in our samples, with Qubit concentrations ranging from 1.30 ng/ml to 80.3 ng/ml. As expected, negative control samples collected in the field yielded no eDNA. Degenerate primers positively detected GBHE and SORA DNA extracted from liver controls, with band fragment sizes of approximately 125 base pairs. Degenerate primers also yielded multiple ~125 bp bands, showing strong evidence for wetland bird DNA detection from eDNA samples. Samples were sequenced on a MiSeq using degenerate bird and vertebrate primers. We focused on analyzing Illumina sequencing data for four species: Sora, King Rail, Virginia Rail, and Least Bittern. Our analyses yielded positive detections for multiple rail species. Least Bitterns were not detected. Ongoing work focuses on adding sampling sites in northern Illinois, increasing sampling duration, and taking soil eDNA samples.
AUTHORS: Michelle Kane, Thomas Gehring – Central Michigan University; Brendan Shirkey, John W. Simpson, Michael A. Picciuto – Winous Point Marsh Conservancy
ABSTRACT: King rails (Rallus elegans) are a secretive marshbird, and the migratory population is of high conservation concern due to declining numbers and loss of historic breeding habitat. In part due to their secretive nature, knowledge gaps exist for basic life history information, including migratory routes, migration chronology and wintering range. We placed satellite transmitters on nine king rails captured in Ohio to gather information about spring and autumn migration chronology and routes, wintering locations, and the potential exposure of migratory king rails to harvest. We received autumn migration data for four individuals and spring migration data for two individuals. Departure dates from the breeding range varied from 30 August to 20 October and spring arrival date to the Upper Midwest was 20 April. Autumn migration for all birds was completed in five days or less. During autumn migration, three individuals migrated from Ohio to the Gulf Coast, and one individual migrated from Pennsylvania to the Atlantic coast. Spring migration lasted longer than autumn migration for both individuals. During spring migration, one individual migrated from the Gulf Coast to the Upper Midwest, and one individual migrated from the Atlantic Coast to the Gulf Coast. We found all king rails with migration data spent the winter in states with king rail hunting seasons during open hunting dates, and thus could potentially be exposed to harvest. This novel information provides critical insight into the migratory movements and wintering range of migratory king rails.
AUTHORS: Stephen A. Tyndel, University of Illinois at Urbana-Champaign; Dr. Jinelle Sperry – CERL-ERDC, University of Illinois at Urbana-Champaign; Dr. Michael P. Ward, University of Illinois at Urbana-Champaign, Illinois Natural History Survey
ABSTRACT: Blue-winged Warblers (Vermivora chrysoptera) and Golden-winged Warblers (Vermivora cyanoptera) are closely related species that hybridize frequently and produce fertile offspring yet tend to mate assortively and often hold overlapping territories. Information on how conspecific and heterospecific interactions impact settlement and habitat selection for both species is lacking.The purpose of this study was to examine the role of social information, specifically song, in habitat selection in both Blue-winged and Golden-winged warblers. Our first objective was to determine if conspecific and heterospecific song can be used to induce settlement in Blue-winged and Golden-winged warblers across their range and whether the response of each species to heterospecific song differs in allopatric and sympatric populations. Our second objective was to determine whether Blue-winged and Golden-winged Warblers males discriminate against heterospecific song and whether discrimination against heterospecific song differs in in allopatric and sympatric populations. To address the first objective, we broadcast songs of Blue-winged warblers and Golden-winged warblers in an area where only Blue-winged warblers breed, where only Golden-winged warblers breed, and where both species breed. To address the second objective, we conducted a simulated territorial intrusion experiment to compare how breeding territorial males of each species respond to heterospecific song in an area where only Blue-winged warblers breed, where only Golden-winged warblers breed, and where both species breed. Data analysis is ongoing but preliminary results for the first objective suggest the strongest response to conspecific cues occurred in the allopatric population of Golden-winged warblers with equivocal results found elsewhere. Responses to heterospecific cues were similarly ambiguous. Preliminary results for the second objective suggest strong species discrimination in sympatry and weak discrimination in allopatry. Ultimately our results will provide important insight into the relationship between these species and the role of social information in habitat selection.
AUTHORS: Jacob A. Shurba, Kali Rush, Jacob Straub – University of Wisconsin-Stevens Point
ABSTRACT: Since September 2017, a study was conducted to examine hen and brood survival rates of Wood Ducks (Aix sponsa) in central Wisconsin. The capturing of wood ducks during the breeding season required use of decoy traps using captive wood duck hens. These captive ducks were purchased from two game farms in the Midwest. Captive decoy hens were placed in traps to attract breeding wood ducks. In March 2018, a small number of the decoy ducks began dying with no clinical signs to diagnose what was causing the mortality. In this study, we reviewed common diseases of waterfowl, the husbandry requirements for captive waterfowl species, and produced potential explanations as to what caused captive duck mortality, as well as recommendations for future studies. We collected data based on the differences in how our ducks were housed compared to recommendations in the literature. We also reviewed the inconclusive pathology reports from the deceased ducks and compared results to common diseases found in waterfowl. We found that the conditions our decoys ducks were kept in could be improved. A combination of living conditions and the adverse effects of being a decoy bird played a significant role in the mortality of these decoy ducks. Recommendations for future studies include a change of living condition to decrease the amount of stress placed on the decoys, and to lessen the amount of time a decoy duck is spending in the trap.
AUTHORS: Tim Lyons, Larkin Powell – University of Nebraska-Lincoln; Mark Vrtiska, Nebraska Game and Parks Commission
ABSTRACT: Bird banding is a basic but important form of population monitoring that is vital to waterfowl management in the U.S. Most often, the data derived from state and federal banding programs are used to estimate survival and harvest rates and distributions across broad geographic regions, but they can also be used to estimate abundance at more local scales. However, absent or limited population surveys, banding efforts, or recoveries, from neighboring states or provinces complicates efforts, leading to ad hoc approaches to deal with these problems during analysis. Here, we use banding and recovery data of Canada geese in Nebraska 2006-2017 to assess the effects of changing harvest regulations on Canada goose demography and estimate abundance. We demonstrate a modified harvest derivation analysis and Lincoln-Peterson estimator to address pitfalls common to these approaches when estimating abundance. Finally, we discuss Jolly-Seber models as an alternative approach to estimating demographic parameters and abundance that circumvents the need for banding or population monitoring programs out-of-state and provides greater detail about the mechanisms responsible for population changes.
AUTHORS: Jeanine M. Refsnider, Henry M. Streby – University of Toledo
ABSTRACT: Studies seeking to conserve habitat critical for the reproductive success of rare species often focus on nesting or spawning habitat. While such habitats are clearly important components of a species’ ecological requirements, conservation efforts focused solely on habitats used for nesting or spawning, without considering the consequences of oviposition-site choice, are, at best, incomplete. At worst, inadequate consideration for the fitness outcomes of oviposition-site choice may create ecological traps if animals are attracted to oviposition sites from which juveniles have very low probabilities of survival. Similarly, management activities such as prescribed burns or selective harvests designed to benefit one species may negatively impact a different species, even if the two species superficially appear to have the same habitat requirements. These problems illustrate the importance of understanding how multiple life stages of multiple species use a landscape, and how the fitness outcomes of differential habitat use impact population trends. We are studying three imperiled, flagship species of the Oak Openings Region in Ohio and Michigan: two terrestrial species commonly associated with oak savannah habitat, red-headed woodpeckers and eastern box turtles, and an aquatic species found in flooded prairies and fens, the spotted turtle. For all three species, we are radio-tracking adults to quantify habitat use and survival; locating and monitoring nests to quantify nest success in different habitat types; and radio-tracking juveniles from those nests to quantify effects of nest habitat on juvenile survival. From these data, we are creating landscape-scale productivity models to predict how management activity in one habitat patch will impact productivity of all three species in nearby habitat patches. Our overall goal is to provide land managers with spatially explicit productivity models for terrestrial and aquatic species of high conservation concern that are directly incorporable into adaptive management plans.
Wednesday January 30, 2019 11:20am - 11:40am EST
HOPE BALLROOM A
AUTHORS: Benjamin W. Tjepkes, Stuart C. Fetherston, Scott E. Hygnstrom – Wisconsin Center for Wildlife, College of Natural Resources, University of Wisconsin-Stevens Point; Brian J. Stemper, Stephen L. Winter – Upper Mississippi River National Wildlife and Fish Refuge, U.S. Fish and Wildlife Service
ABSTRACT: The overall population of bald eagles (Haliaeetus leucocephalus) has increased in range and size across much of North America, since they were listed as a federally Threatened Species in the 1970’s. This increase likely is due in part to the efforts of several federal and state wildlife management agencies in protecting nest sites, an important factor in raptor reproduction. We studied nest-site selection in bald eagles along the 420-km long Upper Mississippi River National Wildlife and Fish Refuge using survey data from 1990 – 2012. Spatial analyses were conducted on known active nest locations using a GIS to develop several metrics relating to bald eagle nesting ecology (e.g., distance to water, surrounding cover type, patch size) and several disturbance metrics (e.g., distance to navigable channel, distance to road). These metrics will then be used to build a mixed-effects resource selection function under a use-availability design for this population. This information will increase the understanding of how bald eagles occupy habitats along the Upper Mississippi River in relation to habitat features and human activities, further contributing to the effective management of this species.
AUTHORS: Luke J. Malanchuk, Michael P. Ward – Illinois Natural History Survey; Heath M. Hagy, U.S. Fish & Wildlife Service; Aaron P. Yetter, Forbes Biological Station, Frank C. Bellrose Waterfowl Research Center
ABSTRACT: The Illinois River Valley (IRV) serves as a crucial stopover area for migratory shorebirds in the midwestern United States despite the high prevalence of row crop agriculture and extensive wetland loss and degradation in the region. Aerial surveys are commonly used to quantify waterfowl abundance and estimate population size, but few attempts have been made to evaluate aerial surveys for other guilds of wetland birds. We investigated whether aerial surveys may provide a good estimate of shorebird use of stopover sites in the IRV. During July-September 2017-2018, and April-May 2018, we conducted concurrent ground and aerial surveys at 5-7 sites per week. Additionally, a single observer counted and assigned all shorebird detections to either "large" (Killdeer (Charadrius vociferous) and larger) or "small" (Pectoral sandpiper (Calidris melanotos) and smaller) size classes, and recorded wetland habitat characteristics at a total of 96 surveyed sites in the IRV. The use of ground counts each survey allows for the calculation of aerial detection probability count bias, while using habitat data of the specific count location from the ground as a correction factor. Aerial surveys detected 89% (N = 93, Range = 0%-250%) of individuals counted during ground surveys. The total number of shorebirds counted in the IRV each week ranged from 1,705 to 30,290, with an average of 10,025 birds. Aerial surveys appear to be an accurate and efficient method to quantifying shorebird abundance along large-river systems. Future plans include questions associated with stopover duration and which species are present in the IRV.