We equipped 28 Marbled Godwit from four locations in North America with miniature satellite transmitters to determine migration routes, strategy, and connectivity. Godwits captured in Utah (n = 13) went to breeding sites in Alberta, Saskatchewan, Montana and North Dakota and wintered along the Baja Peninsula and west coast of mainland Mexico. They used Bear River Migratory Bird Refuge (BRMBR), Utah as a stopover during both north and southbound migration. Godwits captured on Akimiski Island, Nunavut, Canada (n = 7) migrated through the midcontinent USA and wintered at sites along the Gulf of California, Sonora, Mexico. There is overlap in use of Mexico winter and stopover areas between the birds from Akimiski Island and those captured in Utah. Godwits captured in Georgia on the Atlantic coast (n = 6) migrated to breeding grounds in North and South Dakota. Godwits wintering along the Atlantic coast breed in close proximity to those originating from Mexico wintering sites and using BRMBR as a stopover. Godwits tagged on Akimiski Island traveled significantly farther during southbound migration (3862 km) than did godwits tagged in Utah (2533 km) and Georgia (2204 km) (P < 0.001). Godwits tagged in Utah traveled the shortest distance to the first stopover during southbound migration (670 km) (P < 0.001). This short distance between stopovers is characteristic of a “hopping” migration strategy, which is different than the intermediate “skipping” distances traveled by godwits from Canada (1925 km) and Georgia (2204 km), to their first stopover. Utah godwits also had the shortest residency period on winter habitats (174 days) (P < 0.001). Georgia godwits had the shortest southbound migration duration (2 days) (P < 0.02), the shortest residency period at breeding habitats (56 days) (P < 0.01) and the longest residency period on the wintering grounds (303 days) (P < 0.003). (152 pages)

The dynamics of coastal landscapes following major storm events and human interventions significantly impact nesting habitat use by species like the piping plover (Charadrius melodus) along Atlantic coastlines. Our study focused on Fire Island, New York, assessing changes in vegetation succession, plover nesting habitat selection, and suitable nesting habitat availability from 2010 until eight years after Hurricane Sandy. We analyzed classified imagery to quantify vegetative cover changes across the landscape and at nest sites. Results showed an increase of 11.5% change in vegetative cover across the study area, and nest sites experienced an increase in vegetation cover from 0.1% to 6.2% between 2015 and 2020. Selection for four habitat variables (i.e., distance to ocean, least-cost distance to bay, elevation, backshore width) was consistent throughout the study, but post-hurricane nests were situated farther from development and closer to bay areas (Euclidean distance) compared to pre-hurricane. Moreover, suitable nesting habitat peaked immediately post-stabilization but declined in subsequent years. Understanding these landscape shifts provides insights into species prioritization of habitat characteristics during nesting. Piping plovers face predation threats during breeding seasons while balancing consideration of the aforementioned habitat considerations, leading to specific nest placement strategies. Our study examined the relationship between nest site selection and the area visible from nests (viewshed) and evaluated its addition in nest site selection models including habitat variables. Piping plovers exhibited a preference for nest sites with increased predator visibility compared to random selection, indicating a strategic selection process. Initially influential (β = 0.43; CI = 0.28 – 0.58), the role of this predator visibility ('viewshed') diminished (β = -0.13; CI = -0.23– -0.04) as the landscape underwent ecological succession. Topographic variation caused greater visual obstruction at nest sites than vegetation. This study on piping plovers offers insights into the interaction between landscape changes, habitat selection, and predator visibility. The evolving importance of viewshed in nest site selection underscores the dynamic nature of nesting strategies in response to changing environments, and incorporation of this variable can improve the predictive ability of other models as it did for this study. These findings have broader implications for ground-nesting bird species and highlight the importance of considering landscape changes and predator visibility in land management strategies to safeguard vulnerable avian populations. / Master of Science / This is a study of piping plover (Charadrius melodus) nesting behaviors and nesting habitat conditions on Fire Island, New York prior to and following Hurricane Sandy in 2012. Over a decade, our observations documented remarkable alterations in both the landscape and nesting preferences of these birds. Vegetation that was initially covered by overwashed sand from the storm re-emerged in many areas across the study area and reduced the amount of suitable nesting habitat for plovers. Although some factors consistently influenced nesting site selection, after Hurricane Sandy, plovers nested farther from human development and closer to the coastal bay. Moreover, our investigation extended to understanding how these birds strategically choose safe nesting grounds with optimal visibility to potential predators. Initially, plovers nested in areas with greater visibility of predators, but as the landscape experienced vegetation succession nest-site viewshed became less of a priority. We also documented sources of visual obstruction at nests and determined that the topographic features obstructed more area than vegetation; however, sand captured by vegetation contributes to hummocks and dune creation. These findings illuminate the adaptability of piping plover nesting behaviors in response to the changing landscapes. Understanding how the environment changes and how animals adapt to these changes is crucial for creating strategies to protect vulnerable bird populations like piping plovers in coastal areas.

Agriculture has diminished shorebirds’ natural habitat in the Mississippi Alluvial Valley. Remaining natural stopover sites are supplemented with agricultural fields during the fall and winter. This study evaluates the impact of 4 different post-harvest water management strategies on shorebird food abundance and potential agrochemical biomagnification. Chironomid samples estimated abundance, biomass, and chironomid agrochemical concentration in each field. A risk assessment of agrochemical biomagnification to shorebirds was made across all treatments. Of treatments represented on all study sites, winter treatment had greatest chironomid abundance and biomass. Models indicated that days since flood initiation, start date, and temperature are significant predictors of chironomid abundance and biomass. Risk assessment results indicate low risk to shorebirds across all treatments for agrochemicals measured in this study. This study shows that flood timing is more important to providing shorebird resources than trends in abundance and biomass of chironomids, and shorebird risk from agrochemicals measured was minimal.

No description available.

Human disturbance is a significant threat to shorebirds in North America. Disturbance can result in direct mortality or have long-term impacts on the survival of shorebirds. Land managers employ a variety of management techniques to minimize anthropogenic impacts on shorebirds, but because the Atlantic Flyway is ecologically and recreationally diverse, management can vary among sites. This thesis used social science methods to understand the extent to which human disturbance is managed and how human disturbance is managed. Specifically, we surveyed land managers and biologists in the U.S. and Canada portions of the Atlantic Flyway to examine potential disturbances, types of activities that are restricted, when restrictions occur, the perceived effectiveness of management techniques, public compliance with restrictions, and resource needs of managers. With the findings from this research, agencies and organizations that manage shorebirds can assess where to invest time, effort, and resources to reduce disturbance. We also used a survey of dog walkers to ascertain the benefits and constraints to leashing dogs near shorebirds because dog walking is one of the top-rated potential disturbances to shorebirds. Additionally, we sought to understand the personal and social norms related to dog walking and evaluated if a community-based social marketing (CBSM) approach would be enhanced by the addition of norms. Using a CBSM approach, we provided insights on strategies to promote voluntarily leashing of dogs near shorebirds. Through this thesis, we aimed to bridge the needs of people and the needs of shorebirds, in an effort to produce effective conservation outcomes. / Master of Science / Shorebird populations have declined in the past four decades. Declines are due in part to human use of coastal areas, which can result in harm to shorebirds. To reduce human impacts on shorebirds and help land managers make decisions about management, this thesis used social science methods. Using a survey of managers, we found that management primarily occurs during the spring and summer and is less frequently during the fall and winter. Of the human activities that could disturb shorebirds, walking dogs off leash is the most commonly regulated. But people are also least commonly compliant with these regulations. Managers believe that the best ways to reduce disturbance to shorebirds included fencing, informal outreach, and signage. More staff and volunteers are also needed to help reduce disturbance. In a subsequent survey of dog walkers, we learned why people leash (or do not leash) dogs near shorebirds. We found that people leash to protect shorebirds, keep dogs safe, control dogs, and keep dogs from bothering people. People choose not to leash because leashing prevents dogs from exercising and socializing, and people believe dogs respond to commands. People who leash dogs generally believe others expect them to leash their dogs near shorebirds. Knowing why people leash or do not leash can help predict leashing behavior and encourage dog walkers to voluntarily leash dogs near shorebirds. This thesis considers the needs of people and the needs of shorebirds as way to achieve effective conservation solutions.

Human disturbance is a serious threat facing shorebirds, and reducing disturbance presents a significant conservation challenge. It requires an understanding of the complex factors that influence both shorebird biology and human behavior related to shorebirds and coastal environments. This thesis used information from ecological and social science fields, along with the applied knowledge of conservation practitioners to build a more holistic understanding of human-shorebird interactions, specifically related to human disturbance of migrating shorebirds. Further, this research provides practical solutions for better managing these interactions. To accomplish this, we used the Delphi technique, an iterative group communication process, to bring scientists and managers together to develop a shared definition of "human disturbance to shorebirds" and a list of priority disturbance categories that affect migratory shorebirds. Next, we collated and synthesized literature on human disturbance during migration and drivers of human behavior related to disturbance or potential management actions. Then, through manager interviews, we examined how shorebird management decisions are made during migration and explored how managers balance the needs of shorebirds and public use of their sites. The disturbance definition and priority disturbance categories, literature synthesis, and manager interviews were used to create a best practices guidance document for reducing human disturbance to migratory shorebirds in the Northeastern U.S. Finally, we conducted a survey of beachgoers to evaluate a shorebird conservation outreach campaign and examined the factors that influence pro-shorebird behavior change. This research demonstrates how integrating social and ecological information and expert opinion can inform conservation and management. / M. S. / Recreational use of beaches and other coastal environments may negatively impact beach wildlife, such as shorebirds. Reducing the impacts of these potential human disturbances presents a significant challenge to shorebird conservation. This thesis used information from ecological and social science fields, along with the applied knowledge of conservation practitioners to build a more complete understanding of human-shorebird interactions, specifically related to migrating shorebirds. Further, this research provides practical solutions for better managing these interactions. To accomplish this, we used the Delphi technique, an iterative social science method, to bring scientists and managers together to develop a shared definition of “human disturbance to shorebirds” and a list of significant human activities that may negatively affect migrating shorebirds. Next, we collected and synthesized information on human disturbance during migration and aspects of human behavior related to disturbance or potential management actions. Then, through interviews with land managers, we examined how shorebird management decisions are made during migration and explored how managers balance the needs of shorebirds and public use of their sites. The disturbance definition, literature synthesis, and manager interviews were then used to create a management guidance document for reducing human disturbance to migrating shorebirds in the Northeastern U.S. Finally, we conducted a survey with beachgoers to evaluate a shorebird outreach campaign and examined the factors that influence people to adopt more pro-shorebird behaviors. This research demonstrates how integrating social and ecological information and guidance from experts can contribute to shorebird conservation.

Snowy plovers (Charadrius nivosus) are small, ground-nesting shorebirds that are a species of conservation concern throughout North America. Despite increased efforts to understand factors contributing to the decline of snowy plover, little is known about habitat selection and breeding ecology of snowy plover for the large population found in the Great Basin. We tested hypotheses concerning the occupancy and nesting success of snowy plover. First, we identified factors influencing snowy plover nest survival at Great Salt Lake, Utah. We hypothesized that snowy plover would demonstrate differences in nest survival rates across years due to differences in habitat characteristics, predator abundance, human influence, resource availability, and fluctuating water levels. We conducted nest surveys at five sites along the Great Salt Lake to locate new nests or monitor known nests until nest fate was determined. We found 608 nests between 2003, 2005-2010, and 2012. The most common cause of nest failure was predation, followed by weather, abandonment, and trampling. Nest survival estimates ranged from 4.6 -- 46.4% with considerable yearly variation. There was no correlation between researcher activity (visits to nests and trapping of adults) and nest survival. Nests in close proximity to roads had lower survival than nests far from roads. Nests located on barren mudflats also had lower survival than nests in vegetated areas or near debris. We found that nests had a higher probability of survival as they increased in incubation stage. Because nesting areas around the Great Salt Lake host some of the largest concentrations of breeding snowy plover in North America, we suggest that managers consider measures to maintain suitable nesting habitat for snowy plover. Second, we determined factors affecting snowy plover occupancy and detection probabilities in western Utah between 2011 and 2012. We hypothesized that snowy plover would be associated with spring water flows and sparsely vegetated salt flats. We made repeated visits to randomly selected survey plots recording the number of snowy plover adults and habitat characteristics within each plot. We modeled the relationship between snowy plover detection probability and habitat and environmental characteristics. The detection probability was 77% (95% CI = 64 -- 86%) and did not vary by year. There was a positive relationship between ambient temperature and detection probability. Next, we modeled the relationship between snowy plover occupancy and individual habitat characteristics including distance to water, distance to roads, land cover types, and vegetative characteristics. Snowy plover occupancy did not vary by year and was estimated at 12% (95% CI = 7 -- 21%). Occupancy was best predicted by close proximity to water, playa land cover, and minimal shrub cover. We used habitat characteristics that best predicted snowy plover occupancy to generate a predictive habitat model that can help prioritize future snowy plover surveys and guide conservation efforts.

I conducted demographic and behavioral studies of Western Sandpipers (Calidris mauri) breeding on the Yukon-Kuskokwim River Delta, Alaska (1998-2005). In chapter one, I estimated apparent annual survival (product of true survival and site fidelity) while correcting for the probability of encounter for 237 males and 296 females. Overall return rates (individual returned to the site in a subsequent season) were lower for females (40%) than males (65%), as was apparent annual survival (&#177; SE, females = 0.65 &#177; 0.05, males = 0.78 &#177; 0.03), and encounter rate (females = 0.51 &#177; 0.07, males = 0.74 &#177; 0.04). In chapter two, I examined the effects of mate and site fidelity on nesting success (N = 430 nests). Annual divorce rate ranged between 37-83%, with 17-63% of pairs reuniting annually. Reuniting pairs initiated clutches earlier than newly formed pairs, and clutches that were initiated early in the season had higher nest success rates compared to late-season nests. When I controlled for clutch-initiation date, nests tended by individuals with prior breeding-site experience had higher daily survival rates compared to birds breeding at the site for the first time. The effect of site experience was greater for males than females. In chapter 3, I reported that Western Sandpipers exhibited aggregated breeding behavior on a 36 ha plot. Breeding aggregations occurred when dominant and/or older individuals excluded younger, subordinate individuals from preferred habitat. The pattern of habitat occupancy conformed to an ideal despotic distribution with aggregated nesting birds in less preferred habitat experiencing lower reproductive success. In chapter 4, I described and demonstrated the form and function of parent-chick communication in the Western Sandpiper. Through experimental playback of adult vocalizations to chicks in the field, I demonstrated: (1) chicks respond to the alarm call by vocalizing relatively less often and moving away from the signal source, (2) chicks respond to the gather call by vocalizing relatively more often and moving toward the signal source, (3) and chicks respond to the freeze call by vocalizing relatively less often and crouching motionless on the substrate for extended periods of time. I also describe two distinct chick vocalizations (chick-contact and chick-alarm calls). / Ph. D.