Waterfowl

Contributed Oral

 
American Black Duck Brood Ecology in Coastal North Carolina
Amanda Hoyt, Chris Williams, Doug Howell

Although years of breeding data exist for American black ducks (Anas rubripes) in North Carolina, the southern extent of their breeding range, little is known about brood ecology in the area. We monitored 160 black duck nests to hatch or fate in Hyde County, North Carolina over two years (2020-2021). Using spatial data collected via 20 GPS tagged American black duck hens and radio-marked ducklings from their broods, we quantified 1) movement patterns of broods traveling away from the nest to brood-rearing areas, 2) brood behaviors based on movements within different habitat classifications and age-classes, 3) selection of brood-rearing areas at the home range and microhabitat scale, and 4) which variables affect brood survival to Class III (43 days post-hatch). On average, marked broods moved 879 ± 966 m in the initial movement from the nest to a brood-rearing area. The estimated survival of marked ducklings was 0.8571 until 13 days post-hatch when all broods were lost. Management for black duck broods in coastal North Carolina should focus on reducing predators such as raccoons.

 
Wildfire Smoke Disrupts Goose Migration
Cory Overton, Austen Lorenz, Eric James, Ravan Ahmadov, John Eadie, Fiona McDuie, Mark Petrie, Chris Nicolai, Melanie Weaver, Dan Skalos, Shannon Skalos, Andrea Mott, Desmond Mackell, Anna Kennedy, Elliott Matchett, Michael Casazza

Catastrophic wildfires throughout the western United States in 2020 affected movement and behavior of migratory birds. Birds are particularly vulnerable to migration disruptions with limited energetic supplies and reliance on specific physiological and behavioral mechanisms for efficient flight. We show that smoke plumes from large and dispersed wildfires disrupted migration of tule greater white-fronted geese and resulted in disordered migratory paths, extended periods of rafting upon the Pacific Ocean, ultimately resulting in substantial energetic deficit. The smoke concentrations associated with change in migratory behavior reached a spatial extent that exceeded 64% of Washington, Oregon, California, and Nevada combined. We demonstrate indirect effects of large-scale wildfire extending beyond the fire boundaries. As the timing and severity of wildfires has increased in the western United States, there is greater overlap between fire and migration seasons resulting in functional decrease in continental connectivity and increased impacts to migrating species.

 
Survival and Cause-Specific Mortality of American Green-Winged Teal on the Yukon-Kuskokwim Delta, Alaska
Jordan Thompson, Thomas Riecke, Bryan Daniels, Kyle Spragens, Melissa Gabrielson, Chris Nicolai, Ben Sedinger

American green-winged teal (Anas crecca carolinensis; hereafter, teal) are an important harvested species across all flyways in North America. Despite the importance of teal, recent information on variation in vital rates among habitat types and regions is lacking. We used band recovery data and hierarchical autoregressive models to examine temporal, sex-, and age-class variation in survival and cause-specific mortality probability of teal banded at Kgun Lake on the Yukon-Kuskokwim Delta, Alaska from 1997 – 2019. A total of 10,554 adult and juvenile teal of known sex were banded and released at Kgun Lake from 1997 – 2019 and 1,245 were recovered and reported by hunters. Estimates of survival probability for adult female and male teal ranged from 0.44 (95% CI = 0.29 – 0.54) to 0.49 (95% CI = 0.37 – 0.68) and 0.56 (95% CI = 0.50 – 0.61) and 0.58 (95% CI = 0.50 – 0.64), respectively, during our study period. Estimates of survival probability for juvenile female and male teal ranged from 0.36 (95% CI = 0.18 – 0.56) to 0.46 (95% CI = 0.31 – 0.71) and 0.51 (95% CI = 0.38 – 0.61) to 0.56 (95% CI = 0.44 – 0.71), respectively. Estimates of hunting mortality probability were generally greatest for males, with juvenile males exhibiting the highest hunting mortality probability and adult females exhibiting the lowest. Estimates of nonhunting mortality probability were greater and more variable than hunting mortality probability for all sex- and age- classes. Our results indicate that nonhunting mortality contributed the most to total mortality of teal banded at Kgun Lake during our study, and that survival probability of female teal banded at Kgun Lake is lower than other published estimates for teal in Alaska. We recommend managers initiate studies to investigate seasonal and geographic variation in survival and nonhunting mortality.

 
Drivers of Mallard Activity Patterns during Winter
Cory Highway, Abigail Blake-Bradshaw, Nicholas Masto, Ally Keever, Jamie Feddersen, Heath Hagy, Daniel Combs, Bradley Cohen

The spatial and temporal distribution of activity is fundamental to how organisms interact and are affected by their environment. Activity patterns fluctuate both daily and seasonally and are proximately affected by environmental conditions and the state of the individual. Thus, individuals must budget their activity based on a suite of circumstances including variations in weather, physiological state, forage availability, and predation risk. Furthermore, migratory animals must make decisions with an incomplete knowledge of their landscape. Here, we examine the influence of weather, hunting pressure, seasonality, diel period (i.e., day/night), and water conditions on activity patterns of mallards (Anas platyrhynchos) wintering in western Tennessee. We collected hourly GPS locations from 281 mallards of different age and sex classes in winters 2019–2021. Based on a binary analysis of steplengths, we considered that a duck was active when they moved 0.4–20 km. Movements < 0.4 km are associated with loafing behaviors, which we considered an inactive state. Surprisingly, mallards did not alter their activity based on hunting season. Instead, mallard activity was affected by temperature, precipitation, month, and diel period. Mallards decreased their activity as temperatures increased and rainfall decreased. Mallards were also more active earlier in the season and during crepuscular times.  Our results indicate that mallards are more active when conditions necessitate increased foraging or exploratory behavior such as colder weather or a greater distribution of water across the landscape. For managers tasked with increasing opportunity to see and harvest waterfowl, our results suggest that days during and after storm events are when mallards are most active.

 
Migration Stopover Ecology of Cinnamon Teal in Western North America
Desmond Mackell, Michael Casazza, Cory Overton, Patrick Donnelly, David Olson, Fiona McDuie, Joshua Ackerman, John Eadie

Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatio-temporal resolution GSM-GPS transmitters, we tracked the fall migration of 61 Cinnamon Teal across western North America over three years (2017-2019). We marked Cinnamon Teal primarily during spring/summer in important breeding and molting regions across seven states (California, Oregon, Washington, Idaho, Utah, Colorado, and Nevada). We assessed migration routes and timing, detected 261 fall stopover sites, and identified specific ecoregions where sites were located. We classified underlying habitats for each stopover site and measured habitat selection for 12 habitat types within each ecoregion. Cinnamon Teal selected a variety of flooded habitats including natural, managed, and riparian wetlands; flooded agriculture (including ditches); lakes and reservoirs; and urban ponds. Wetlands associated with agriculture were the highest used habitat type (24%) and over 72% of stopover locations were on private land. Resources used by Cinnamon Teal reflect wetland availability across the west, and further emphasize adaptability to dynamic resource conditions in arid landscapes. Reliance on potentially sub-optimal wetland habitat (golf course water features and agricultural ditches) may be indicative of a lack of suitable wetland habitats across the western landscape. Our results provide much needed information on spatial and temporal resource use by Cinnamon Teal during migration and indicate important wetland habitats for migrating waterfowl in the western United States.

 
Shifts in Migration Timing and Pathways of Prairie Waterfowl from 60 Years of Banding Data
Barbara Frei, Sarah Gutowsky, Christian Roy

Changes in the phenology of migrating birds, or lack-thereof, in consequence of a rapidly changing world, have distinct implications for the success, survival, and management of migratory birds worldwide. Shift in phenology and migration movements may have extensive implications, including: loss of socioeconomic opportunities by waterfowl hunters and associated tourism, reduced efficacy of monitoring and management efforts by land managers and policy makers, and conservation implications of habitat overuse in key staging areas. Using nearly 60 years of banding and recovery data from three harvested waterfowl species across North America, we identified changes in migration phenology and patterns. The banding data included Mallards, Blue-winged Teals, and Northern Pintails that were banded from 1960 – 2019 in the three prairie provinces of Canada, and were subsequently shot or found dead (i.e., bands recovered) during the fall (September – December) hunting season across North America. We visualized spatiotemporal changes in the phenology and distribution of fall migration using kernel distribution estimation (KDE; Calenge et al. 2007) and assessed the spatial relationships using STAMP (Spatio-Temporal Analysis of Moving Polygons; Long et al. 2018). We found some species, such as the Mallard, are not only delaying fall migration, but are remaining in more northerly staging or overwintering areas, and even moving across different flyways than the same population in previous decades. Comparing these movements to climate change provides further insight to possible human and climate-induced drivers of changing migration phenology of waterfowl.

 
The Influence of Experimental Disturbance on Mallard Space Use and Movements during Winter
Abigail Blake-Bradshaw, Nicholas Masto, Cory Highway, Ally Keever, Jamie Feddersen, Heath Hagy, Daniel Combs, Bradley Cohen

Winter is an energetically and physically stressful time for animals and may be especially demanding for hunted species such as waterfowl.  Often, wildlife managers provide spatial sanctuaries and food resources for waterfowl along autumn migration routes and across wintering areas; however, studies indicate that waterfowl increase their use of sanctuaries diurnally during hunting seasons making many waterfowl largely unavailable to hunters.  Furthermore, increased use of sanctuaries by waterfowl may result in pressure from the public and other stakeholders to offer access to sanctuaries for hunting or other activities (e.g., birding, photography).  Despite seasonal closures of sanctuaries to the public, empirical evidence quantifying waterfowl responses to a gradient of disturbance regimes is lacking and may have greater population-level consequences than is currently understood.  To determine how different intensities of disturbances on sanctuaries affected daily movements and space use post-disturbance, we placed GPS/GSM transmitters programmed to take hourly locations on 180 mallards (Anas platyrhynchos).  We simulated distinct disturbance treatments which represent activities that potentially occur on waterfowl sanctuaries including 1) waterfowl surveys from a vehicle, 2) pedestrian access, and 3) accessing wetland units via motor boat or all-terrain vehicle (ATV).   Disturbing mallards had little effect on their overall sanctuary use, and hunting season and diel period were more influential.  Similarly, disturbance only marginally increased daily space use of mallards.  Daily utilization distributions were greater during the hunting season (31.9 ha [25.5–40.0]) compared to the post hunting period where mallards used approximately 50% less area after hunting season. Disturbance, however, did increase daily distance moved; specifically, the pedestrian access resulted in an 11% increase (+0.7 [0.2–1.9 km) in daily distance, whereas vehicular access resulted in less severe impacts on mallard behavior. We discuss our findings in context of wildlife managers tasked with balancing stakeholder opportunity or satisfaction while supporting waterfowl populations.

 
Mortality Dynamics of Wood Ducks That Breed in the Upper Mississippi River Great Lakes Region
Andrew Greenawalt, Thomas Riecke, Drew Fowler, Ben Sedinger

Research has been inconclusive about how harvest affects the survival process in waterfowl, with mixed support for both the additive mortality hypothesis and the compensatory mortality hypothesis. Wood duck (Aix sponsa) abundance in the Upper Mississippi River Great Lakes Region (hereafter UMRGLR) has fluctuated through time and it is unclear how harvest has influenced this variability. We used Brownie band recovery models in a Bayesian hierarchical framework to estimate wood duck harvest and survival probabilities in the UMRGLR from 1961-2018. We partitioned our UMRGLR data into states (Minnesota, Wisconsin, and Michigan) to examine the affect harvest regulations (e.g., bag limits, hunting season lengths) have on wood duck harvest mortality and Bird Conservation Regions (hereafter, BCR 12, 22, and 23) to examine how environment factors (e.g., drought) influence non-hunting mortality of northern breeding wood ducks. Preliminary results suggest that wood duck harvest mortality partially compensates for non-harvest mortality for all age- and sex- classes[SB1] . Our analysis shows spatial and temporal variation in wood duck mean harvest probabilities that ranged from as low as 0.0337 (95% C.I. 0.0276-0.0404) for adult females in Michigan to as high as 0.0808 (95% C.I. 0.0700-0.0925) for juvenile males in Wisconsin. For the BCR’s mean harvest probabilities ranged from 0.0337 (95% C.I. 0.0287-0.0391) for adult females in BCR 12 to  0.0768 (95% C.I. 0.0672-0.0870) for juvenile males in BCR 23. Our results show that relative to harvest mortality, non-harvest mortality contributes more to spatial and temporal variation in the survival process for wood ducks that breed in the northern extent of the Mississippi Flyway, and that harvest partially compensates for non-harvest mortality. Our findings suggest that when managers are unable to solicit a population level response through harvest management, they might examine other factors affecting survival or the recruitment process of wood ducks in the UMRGLR.  [SB1]Cohort

 
Assessment of Credentials and Experiences for a Successful Career in Waterfowl Science and Conservation
Lauren Hernandez-Rubio, Richard Kaminski, Shari Rodriguez, Althea Hagan, William Conner

A paradigm shift in the wildlife profession from a focus on game management to a broader emphasis on biodiversity and its conservation has led to a transition in skills important for a successful career in the profession. Traditional emphases, such as habitat management, quantitative methods, species identification, field research, etc., remain important; however, the broadened focus reflects an increase in non-consumptive users and a growing awareness of the importance of human dimensions, inclusivity, and leadership. Identifying credentials and experiences for success in the field of waterfowl and wetlands science and conservation is of particular importance within the profession as the number of universities offering waterfowl-centric programs has declined since the 1970s (~40%). We conducted a survey in October 2019 of attendees of the 2013, 2016, and 2019 North American Duck Symposium. Our objectives were to determine (1) course work and experiences that professionals deemed important for success in the profession of waterfowl science and conservation, (2) technical skills, professional society certification(s), and personal traits considered important, and (3) socio-demographic variables and years of professional experience that may further predict credentials for a successful career. Response rate to the questionnaire was 53% (364/690). Professionals and students of both genders agreed on the importance of traditional technical field and practical skills, such as animal capture and handling, wildlife identification, wetland classification/delineation, and truck/ATV operation. They also agreed on the importance of statistics and modeling and communication of research to colleagues and the public. Our results are important to the waterfowl profession, and a similar survey should be administered to attendees of annual meetings of The Wildlife Society.

 
Geographic Coverage of Continental Populations and Stocks of Priority Waterfowl Species By the USFWS Waterfowl Breeding and Habitat Survey and Other Breeding Waterfowl Surveys
Kristopher Winiarski, Emily Silverman, John Sauer

The USFWS Waterfowl Breeding Population and Habitat Survey (WBPHS) is currently under review to determine whether the survey can be improved to better meet monitoring needs for priority waterfowl species. As part of the review, we used predictions from published spatial waterfowl models in Canada and from eBird Status and Trends in Alaska and the contiguous US to quantify the percentage of continental populations and stocks of priority waterfowl species that are currently surveyed by the WBPHS and other waterfowl breeding.  We used yearly predictions for Canada to document whether coverage of waterfowl populations by the WBPHS is changing over time and to assess year-to-year variation in coverage between 1990 and 2014. We found that the percentage of populations of priority waterfowl species surveyed by the WBPHS was highest for American black duck, and eastern stocks (e.g., American green-winged teal, goldeneye and ring-necked duck), which are surveyed with the current eastern survey area strata, and lower for priority species with northern breeding distributions (e.g., scaup and scoter species) or species with widespread distributions or stocks in the Pacific Flyway (e.g., continental populations of mallard and northern pintail and western mallards). State and provincial surveys provide important supplementary coverage of the continental mallard population and the western mallard and eastern American green-winged teal stocks. Annual variability of the percentage of the population surveyed by the WBPHS was high for some species (e.g., northern pintails), and temporal trends in coverage occurred for many species. Variability in the percentage surveyed and not just total percentage surveyed should be considered when identifying which continental populations and stocks may need additional survey coverage outside the current spatial extent of the WBPHS.

Contributed Oral
Location: Virtual Date: November 4, 2021 Time: 3:00 pm - 4:00 pm