Waterfowl Posters


Impact of Canada Goose Molt Captures on the Number of Nests Based on 19 Years of Data in New Jersey.
april simnor, Nicole Rein

Canada goose (Branta canadensis) overabundance in New Jersey creates human-wildlife conflicts including accumulation of feces, overgrazing of lawns, negative impacts on water quality, and human health and safety concerns.  In 2019, the resident Canada goose population in New Jersey was 70,652 which is higher than the management objective of 41,000 geese set by the Atlantic Flyway Council.  Egg addling and molt captures with euthanasia are part of USDA Wildlife Services’ integrated wildlife damage management for Canada geese in New Jersey.  We analyzed 19 years of data to determine the impact of molt captures on nest numbers.  Sites analyzed include 65 sites where USDA Wildlife Services conducted both egg addling and molt captures with euthanasia as well as 48 sites where USDA Wildlife Services conducted only egg addling.  In comparing two consecutive years of data, we found an average 6% reduction in number of nests at egg addling sites and an average 25% reduction in number of nests at the molt capture and egg addling sites.  Sites with an additional molt capture in subsequent years resulted in a further nest reduction.  We further analyzed nest data to determine if nest numbers remained stable at two-year, five-year, and eight-year intervals.  At egg addling sites, the nest numbers remained stable at all intervals.  At molt capture and egg addling sites, we analyzed the nest figures after a site’s most recent molt capture.  We found that nest numbers remained consistent at the two-year and five-year interval with an average change of -3% (n=39) and 1% (n=23), respectively.  Whereas, the eight-year interval had an average increase of 14% (n=9).  Based on our 19 years of data, egg addling alone has minimal impact on nest numbers while molt captures with euthanasia have resulted in the reduction of nest numbers.

Health and Behavior of Migratory and Resident Urban Canada Geese
Maureen Murray, Sean Obrochta, Ryan Askren, Maria Luisa Savo Sardaro, Katherine Amato, Seth Magle, Rachel Santymire

Many urban wildlife populations are more sedentary and exhibit less migratory behavior than rural populations, which may have important consequences for wildlife health and human-wildlife conflict. For example, migration is energetically costly and may increase physiological stress. Migration may also confer health benefits, for example if it promotes more diverse gut microbiomes by exposing migrants to different types of habitats. Further, year-round residency may promote greater habituation to people, which may lead to human-wildlife conflict. In this study, we tested whether migratory Canada geese (Branta canadensis) exhibit 1) higher physiological stress levels, 2) more diverse gut microbiomes, and 3) lower tolerance of human presence relative to year-round urban residents. We collected fecal samples and behavioral data from 32 GPS-tracked geese (10 migrants, 22 residents) in Chicago, Illinois, USA during the fall migratory period (September – October 2018). We analyzed fresh fecal samples for fecal glucocorticoid metabolite concentrations as a measure of physiological stress and sequenced bacterial 16S rRNA for microbiome diversity and composition. We also recorded the minimum distance we could approach geese before they moved away (i.e. flight initiation distance). We found that physiological stress levels did not significantly differ between migrants and residents (p=0.61); however, they were higher in samples collected during goose capture (p<0.001), validating our approach. Migrants exhibited lower individual variation in microbiome composition (p<0.01) and lower microbial diversity (p<0.05) relative to residents. Migrants also moved away at a greater distance relative to residents (p=0.003). Our results suggest that migrants do not experience a prolonged state of physiological stress following migration. Although residents had more diverse gut flora, the compositional shifts and high individual variation in microbiome composition among residents suggests imbalanced microbial communities. In sum, our results suggest that year-round residency may have detrimental effects of goose health and may promote human-goose interactions in parks.

Microplastic Prevalence in North American Waterfowl
Jennifer Sweatman, Clarissa Moore, Mia Locquegnies

Plastic pollution is pervasive in the environment and, over time, breaks down into microplastics (fragments ≤5mm). Microplastics often become incorporated in animal tissues through ingestion. Current research on microplastics is primarily focused on marine organisms, with a majority of the research investigating the prevalence of microplastics in seabirds. While recent research has identified microplastics in terrestrial soils and aquatic environments, few studies have been conducted on waterfowl. To address this gap in the literature, we analyzed the contents of the proventriculus, gizzard and intestines of North American waterfowl. Waterfowl gastrointestinal tracts from multiple species and feeding habits (divers and dabblers) were donated by local hunters. We hypothesized that microplastic abundance would differ based on species and feeding type of waterfowl. Of the gut contents analyzed, over 90% contained microplastics. Microplastic abundance was not significantly different between waterfowl species or feeding habits, but location within the gastrointestinal tract, proventriculus, gizzard, or intestines, was significant. The abundance of microplastics was significantly lower in the intestines than the proventriculus. This suggests that the majority of microplastics found in our samples were eaten within a short time of being harvested. The results of this study illustrate the pervasive nature of plastic pollution in the environment. As such, incorporating microplastic assessment into waterfowl conservation efforts is increasingly important.

Comparisons between the Spatiotemporal Population Dynamics of Two Dabbling Duck Species – SRIP
Madeleine Lohman, Thomas Riecke, James Sedinger, Perry Williams
Research has established that wildlife responses to environmental heterogeneity vary according to life-history strategies and paces. However, few studies have compared spatiotemporal variation in population dynamics between species at landscape-level scales. The population distribution of dabbling ducks in the Prairie Pothole Region (PPR) of the northern Great Plains has shifted over the past 60 years with changing agricultural patterns and climate. These spatial and temporal gradients of land use, combined with natural heterogeneity on the landscape, create an ‘accidental experiment’ to see how changing environmental conditions affect broad-scale population dynamics. Despite their differences in life-history paces, mallards (Anas platyrhynchos) and blue-winged teal (Anas discors) both belong to the same guild of dabbling ducks and have large populations in the PPR that have fluctuated over the past several decades. Using release and harvest data from 1961 to 2015, we will model age ratios and female survival in a Bayesian framework for both species. We predict the age ratios of both species will be higher in the southeast portion of the PPR, but blue-winged teal age ratios may favor juveniles at higher rates. Survival for both species may not show any spatial pattern; however, mallards may have a higher survival rate across all time periods. Comparisons of spatiotemporal variation in demographic rates can help explain processes that have created distinct long-term population trends between these species. This research may also provide a model to help predict population responses to environmental heterogeneity for these species and other dabbling ducks lacking data.
Influences of Natural and Unnatural Risk on Waterbird Behavior – SRIP
Anna Sarkisian, Zane Fuss, Darren Wood
The proposed research project will evaluate the effects that natural risk events, including the presence of predators or competition, as well as unnatural risk events, including motorized and non-motorized recreational vessels, has on double-crested cormorant (Phalacrocorax auratus) and great blue heron (Ardea herodias) behavior.  The research will occur in ten public lakes and wetlands throughout northwestern Pennsylvania from June 1, 2021 through August 1, 2021. Sites will be classified as recreational and non-recreational, with non-recreational serving as the control for unnatural risk. To eliminate the possibility of disturbance during sampling, focal random sampling will occur at a distance no closer than 50 meters from the individual being sampled. Sampling will occur in fifteen-minute increments using a video recorder with a 60x optical zoom. A 5-minute delay between behavior recordings and detection will be utilized to reduce observer influence. During the sampling periods, all behaviors will be recorded and analyzed for effects of disturbance. Behaviors to be analyzed include foraging; the time spent searching, stalking, and consuming prey, vigilance, preening (manipulating feathers), resting (no behavior performed), or dispersal from the area. The research performed will give insight into the effects that recreational activity and the presence of predators have on the behaviors of double-crested cormorants and great blue heron.
Overwintering Mallard Body Mass Trends in the Lower Mississippi Alluvial Valley of Arkansas and Mississippi from 1979-2021 – SRIP
John Veon, Brett DeGregorio, Luke Naylor, Kenneth Reinecke, Brad Dabbert, David Krementz
Recent research from Europe suggests that mallard body mass has increased over recent decades, in part because of benign winter climate and increased food availability. Other studies suggest changes in body mass may result from introgressive hybridization with pen-reared mallards that were released into the wild. We are analyzing body mass trends in mallards sampled throughout the Lower Mississippi Alluvial Valley (LMAV) of Arkansas and Mississippi from 1979-2021 to establish whether similar changes in mallard body mass have occurred. During Arkansas and Mississippi duck hunting seasons, we measured harvested mallards from hunters, hunting clubs, and plucking stations. For each bird, we determined sex, age, and recorded body mass measurements. We will explore mallard body mass trends within seasons and across time, as well as in response to extrinsic meteorological variables using a generalized linear mixed model for each sex and age group of mallards. Based on the European mallard body mass trends, we hypothesize that mallard body mass will have increased between 1979 and present. As there is some evidence that flooding across the landscape as well as a warmer climate relates to forage availability, we hypothesize that mallards will have the highest body mass when cumulative rainfall is higher and winter climate is warmer.
Assessing Use of Unmanned Aerial Systems and Artificial Intelligence for Monitoring Non-Breeding Waterfowl Abundance in Missouri – SRIP
Reid Viegut, Elisabeth Webb, Andrew Raedeke
Monitoring waterfowl populations provides the basis for improving habitat quantity and quality for waterfowl, establishing harvest regulations, and ensuring sustainable waterfowl populations for the future through components of state natural-resource management objectives, joint-venture objectives, and the North American Waterfowl Management Plan. Waterfowl biologists currently use a variety of population and habitat monitoring methods ranging from informal ground observations to more systematic approaches, including low-level manned aerial surveys and structured ground counts. In recent years, Unmanned Aerial Systems (UAS) have emerged as a new technology for monitoring wildlife populations.  UAS may provide a safer and more precise alternative to traditional aerial survey techniques, however, the feasibility of using UAS to estimate waterfowl abundance accurately and precisely on refuges during migration stopover and wintering periods is still unknown. We are using a DJI Mavic 2 Pro to collect imagery of various species of waterfowl on Missouri Department of Conservation conservation areas October – February 2020-2021 and 2021-2022. We are collecting images at 15, 30, 60, and 90 meters over habitats of flooded corn, emergent vegetation, submergent vegetation, land, and ice, and under varying environmental conditions of full sun to full cloud coverage and different wind speeds to train artificial intelligence algorithms in the identification and counting of waterfowl from aerial images collected with a UAS. In some habitat types under certain conditions, an artificial intelligence algorithm achieved precision and recall scores > 0.95. Ongoing work involves further improving and the detection and accuracy of the artificial intelligence algorithms and evaluating the precision of waterfowl abundance surveys using a UAS. The synergies of these new technologies, which include UAS, improved camera sensors, and deep learning computer algorithms, offer the opportunity to develop novel and improved techniques for monitoring waterfowl populations and wetland habitats and overcome some of the existing challenges with current survey
Habitat Variables Associated with Foraging Site Selection of Great Blue Heron – SRIP
Zane Fuss, Anna Sarkisian, Darren Wood
The great blue heron (Ardea herodias) is a prominent and widespread waterbird with a range occupying the majority of North America. Although their population size is stable, continued recreational and industrial development of shorelines or watersheds may impact occupancy of current foraging habitats. While research of great blue heron habitat has largely focused on variables associated with broad-scale site selection, there is insufficient research understanding the physical, biological, and chemical variables associated with microhabitat selection (i.e. foraging site selection). To determine microhabitats associated with foraging site selection and foraging success rates, great blue herons will be observed in ten public lakes and wetlands across northwestern Pennsylvania using random focal sampling from June 1, 2021 through August 1, 2021. Observations of individuals will occur from 50 meters away to avoid disturbance as well as a 5-minute delay between foraging behavior recordings and detection of an individual. Recordings of foraging behavior will occur for 15-minutes or until the heron has been disturbed from the area. Following the recording session, microhabitat data will be collected to determine variables associated with site selection. Physical variables to be measured include water depth and distance to shoreline, whereas biological variables will include percent aquatic plant cover, aquatic plant species richness, and terrestrial canopy coverage. Water chemistry variables including temperature, algae content (chlorophyll and phycocyanin content), conductibility, and turbidity will also be measured. Results of this study will help landowners, wildlife managers, and biologists identify the conditions needed for conservation or preservation of foraging habitats and overall continued success of great blue herons.   

Location: Virtual Date: November 4, 2021 Time: 11:00 am - 12:00 pm