{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/141160"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/141160","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Shorebirds in a changing landscape: Assessing the top-down and bottom-up drivers of American oystercatcher (<i>Haematopus palliatus</i>) reproductive success in the Virginia barrier islands","abstract":"Understanding the factors that affect population growth is a vital component of the conservation of imperiled species. On the United States (U.S.) Atlantic and Gulf coasts, the American oystercatcher (Haematopus palliatus) is largely managed within a conservation framework that aims to identify and manipulate factors that limit reproductive success. Coordinated research and monitoring across the species' range have identified several key threats to the survival of nests and chicks, including predation, habitat loss and degradation, and human disturbance. However, the relative importance of those threats can change, and new threats may emerge, as coastal ecosystems dynamically respond to global climate change. In the Virginia barrier islands, where American oystercatcher reproductive success has been historically high due to the widespread availability of undeveloped coastal habitat, declines in the average annual productivity rate of American oystercatchers since 2016 may signal evolving threats to reproduction. To provide insight into changing threats to American oystercatcher productivity in Virginia, and to inform adaptive management, we investigated the drivers of American oystercatcher reproductive success on the Virginia barrier islands. We considered three components of American oystercatcher conservation and management: (1) interactions between American oystercatchers, their conspecifics, and a complex predator community; (2) altered availability of nesting habitat due to climate-driven changes within barrier island ecosystem; and finally, (3) community support for widespread protection of the barrier island landscape and participation in conservation initiatives designed to protect breeding American oystercatchers, such as adhering to island access restrictions and recreation guidelines. We first investigated nest and chick survival on Metompkin Island and Fisherman Island—two islands that represent a range of geomorphological and ecological conditions present within the Virginia barrier island system—in 2021–2023 using a combination of field-based surveys and automated radio telemetry methods. Next, we used remotely sensed data to explore how climate-driven ecosystem state change on the Virginia barrier islands may be driving changes in the abundance and distribution of American oystercatcher nesting habitat across the barrier island system from 2004–2021. Finally, we evaluated the short-term outcomes of a field-based high school environmental education program using pre- and post-program surveys of students to assess how environmental education may promote changes in knowledge and public attitudes related to shorebird conservation initiatives in Virginia. Through routine surveys of nests and radio-marked chicks, we found that the cumulative probability of a nest surviving the incubation stage was greater than 90%, while the cumulative probability of a chick surviving from hatch to fledging was approximately 51%. Thus, chick survival, rather than nest survival, may be limiting reproductive success in the Virginia barrier islands. Flooding was a primary cause of nest loss (32% of failed nests), and storm-driven overwash in late April and early May forced peak nesting to shift later in the breeding season as breeding pairs renested, particularly in 2022. Despite ongoing management of mammalian predators through lethal removal, reproductive success still appears to be limited through the top-down effects of predation on both stages of American oystercatcher reproduction, as both nests (22% of failed nests) and chicks (46.4% of marked chicks) were lost from non-mammalian predators, including raptors (e.g., peregrine falcons [Falco peregrinus] and great horned owls [Bubo virginianus]) and Atlantic ghost crabs (Ocypode quadrata). Remotely sensed data provided an opportunity to investigate factors for which we lacked data collected in situ. Using aerial orthoimagery of the barrier islands collected by the National Agriculture Imagery Program (U.S. Department of Agriculture), we found that habitat abundance increased by 228.26 ha from 2004–2016, and then decreased by 124.38 ha from 2016–2021. Across the 2004-2021 timespan, abundance of American oystercatcher nesting habitat (defined as sites where the relative probability of nesting is ≥ 90%) was both temporally and spatially variable within the Virginia barrier island systems, with changes on only a few islands (e.g., Metompkin Island, Cedar Island, and Cobb Island) driving most of observed system-wide trends. We suggest that temporal variability may be a result of patterns of storminess along the Virginia coast 2004–2021, while spatial variability is likely due to localized differences in the geomorphological and ecological processes that control habitat availability, including sediment dynamics (e.g., sand erosion versus accretion), dune-building processes, and vegetative succession. Finally, we used an evaluation of The Nature Conservancy's field-based environmental education program for high school students as a case study to demonstrate the value of incorporating environmental education into a multidisciplinary conservation program. Using surveys that assessed components of environmental literacy—including knowledge of ecological concepts, feelings of connection and stewardship toward the local ecosystem, and behavioral intentions—we examined short-term educational outcomes for students who participated in a formal field trip to one of the Virginia barrier islands. By comparing responses on surveys delivered immediately before and immediately after the field trip, we found that participation in the field trip increased students' knowledge about barrier island ecosystems and sense of place attachment. Additionally, students self-reported positive environmental literacy outcomes on the post-trip assessment, including increased interest in scientific learning, increased likelihood of participating in stewardship behaviors, and increased intentions to participate in conservation behaviors. Given the pace at which ecosystems are changing in response to climate change and anthropogenic drivers, it is expected that the factors limiting American oystercatcher population growth will also continuously change. To protect against population declines, shorebird managers will need to continuously monitor for change. They will also need to consider the use of creative management approaches, including ecosystem-based management to address complex predation and climate threats, and environmental education and outreach programs to promote broad community support for conservation initiatives.","abstract_html":"Understanding the factors that affect population growth is a vital component of the conservation of imperiled species. On the United States (U.S.) Atlantic and Gulf coasts, the American oystercatcher (Haematopus palliatus) is largely managed within a conservation framework that aims to identify and manipulate factors that limit reproductive success. Coordinated research and monitoring across the species&#x27; range have identified several key threats to the survival of nests and chicks, including predation, habitat loss and degradation, and human disturbance. However, the relative importance of those threats can change, and new threats may emerge, as coastal ecosystems dynamically respond to global climate change. In the Virginia barrier islands, where American oystercatcher reproductive success has been historically high due to the widespread availability of undeveloped coastal habitat, declines in the average annual productivity rate of American oystercatchers since 2016 may signal evolving threats to reproduction. To provide insight into changing threats to American oystercatcher productivity in Virginia, and to inform adaptive management, we investigated the drivers of American oystercatcher reproductive success on the Virginia barrier islands. We considered three components of American oystercatcher conservation and management: (1) interactions between American oystercatchers, their conspecifics, and a complex predator community; (2) altered availability of nesting habitat due to climate-driven changes within barrier island ecosystem; and finally, (3) community support for widespread protection of the barrier island landscape and participation in conservation initiatives designed to protect breeding American oystercatchers, such as adhering to island access restrictions and recreation guidelines. We first investigated nest and chick survival on Metompkin Island and Fisherman Island—two islands that represent a range of geomorphological and ecological conditions present within the Virginia barrier island system—in 2021–2023 using a combination of field-based surveys and automated radio telemetry methods. Next, we used remotely sensed data to explore how climate-driven ecosystem state change on the Virginia barrier islands may be driving changes in the abundance and distribution of American oystercatcher nesting habitat across the barrier island system from 2004–2021. Finally, we evaluated the short-term outcomes of a field-based high school environmental education program using pre- and post-program surveys of students to assess how environmental education may promote changes in knowledge and public attitudes related to shorebird conservation initiatives in Virginia. Through routine surveys of nests and radio-marked chicks, we found that the cumulative probability of a nest surviving the incubation stage was greater than 90%, while the cumulative probability of a chick surviving from hatch to fledging was approximately 51%. Thus, chick survival, rather than nest survival, may be limiting reproductive success in the Virginia barrier islands. Flooding was a primary cause of nest loss (32% of failed nests), and storm-driven overwash in late April and early May forced peak nesting to shift later in the breeding season as breeding pairs renested, particularly in 2022. Despite ongoing management of mammalian predators through lethal removal, reproductive success still appears to be limited through the top-down effects of predation on both stages of American oystercatcher reproduction, as both nests (22% of failed nests) and chicks (46.4% of marked chicks) were lost from non-mammalian predators, including raptors (e.g., peregrine falcons [Falco peregrinus] and great horned owls [Bubo virginianus]) and Atlantic ghost crabs (Ocypode quadrata). Remotely sensed data provided an opportunity to investigate factors for which we lacked data collected in situ. Using aerial orthoimagery of the barrier islands collected by the National Agriculture Imagery Program (U.S. Department of Agriculture), we found that habitat abundance increased by 228.26 ha from 2004–2016, and then decreased by 124.38 ha from 2016–2021. Across the 2004-2021 timespan, abundance of American oystercatcher nesting habitat (defined as sites where the relative probability of nesting is ≥ 90%) was both temporally and spatially variable within the Virginia barrier island systems, with changes on only a few islands (e.g., Metompkin Island, Cedar Island, and Cobb Island) driving most of observed system-wide trends. We suggest that temporal variability may be a result of patterns of storminess along the Virginia coast 2004–2021, while spatial variability is likely due to localized differences in the geomorphological and ecological processes that control habitat availability, including sediment dynamics (e.g., sand erosion versus accretion), dune-building processes, and vegetative succession. Finally, we used an evaluation of The Nature Conservancy&#x27;s field-based environmental education program for high school students as a case study to demonstrate the value of incorporating environmental education into a multidisciplinary conservation program. Using surveys that assessed components of environmental literacy—including knowledge of ecological concepts, feelings of connection and stewardship toward the local ecosystem, and behavioral intentions—we examined short-term educational outcomes for students who participated in a formal field trip to one of the Virginia barrier islands. By comparing responses on surveys delivered immediately before and immediately after the field trip, we found that participation in the field trip increased students&#x27; knowledge about barrier island ecosystems and sense of place attachment. Additionally, students self-reported positive environmental literacy outcomes on the post-trip assessment, including increased interest in scientific learning, increased likelihood of participating in stewardship behaviors, and increased intentions to participate in conservation behaviors. Given the pace at which ecosystems are changing in response to climate change and anthropogenic drivers, it is expected that the factors limiting American oystercatcher population growth will also continuously change. To protect against population declines, shorebird managers will need to continuously monitor for change. They will also need to consider the use of creative management approaches, including ecosystem-based management to address complex predation and climate threats, and environmental education and outreach programs to promote broad community support for conservation initiatives.","abstract_has_math":false,"creators":["Call, Mikayla Nicole"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Fisheries and Wildlife Science","degree_department":"Fish and Wildlife Conservation","school":null,"contributors":[],"advisors":[],"committee_chairs":["Karpanty, Sarah M."],"committee_members":["Fraser, James D.","Chaves, Willandia A.","Wilke, Alexandra L.","Rogers, Haldre S."],"year":2026,"date_issued":"2026-02-04","date_published":"2026-02-04","updated_at":"2026-07-22T22:19:18Z","subjects":["American oystercatcher","climate change","conservation","ecosystem change","environmental education","habitat","Haematopus palliatus","productivity","survival","Virginia"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:45300"],"render_values":[{"text":"vt_gsexam:45300","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/141160","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Karpanty, Sarah M."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Fraser, James D.","Chaves, Willandia A.","Wilke, Alexandra L.","Rogers, Haldre S."]},{"key":"dc:contributor.department","label":"Department","values":["Fish and Wildlife Conservation"]},{"key":"dc:creator","label":"Author","values":["Call, Mikayla Nicole"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-02-05T09:00:30Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-02-05T09:00:30Z"]},{"key":"dc:date.issued","label":"Date","values":["2026-02-04"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Fisheries and Wildlife Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["American oystercatcher","climate change","conservation","ecosystem change","environmental education","habitat","Haematopus palliatus","productivity","survival","Virginia"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:45300"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/141160"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Understanding the factors that affect population growth is a vital component of the conservation of imperiled species. On the United States (U.S.) Atlantic and Gulf coasts, the American oystercatcher (Haematopus palliatus) is largely managed within a conservation framework that aims to identify and manipulate factors that limit reproductive success. Coordinated research and monitoring across the species' range have identified several key threats to the survival of nests and chicks, including predation, habitat loss and degradation, and human disturbance. However, the relative importance of those threats can change, and new threats may emerge, as coastal ecosystems dynamically respond to global climate change. In the Virginia barrier islands, where American oystercatcher reproductive success has been historically high due to the widespread availability of undeveloped coastal habitat, declines in the average annual productivity rate of American oystercatchers since 2016 may signal evolving threats to reproduction. To provide insight into changing threats to American oystercatcher productivity in Virginia, and to inform adaptive management, we investigated the drivers of American oystercatcher reproductive success on the Virginia barrier islands. We considered three components of American oystercatcher conservation and management: (1) interactions between American oystercatchers, their conspecifics, and a complex predator community; (2) altered availability of nesting habitat due to climate-driven changes within barrier island ecosystem; and finally, (3) community support for widespread protection of the barrier island landscape and participation in conservation initiatives designed to protect breeding American oystercatchers, such as adhering to island access restrictions and recreation guidelines. We first investigated nest and chick survival on Metompkin Island and Fisherman Island—two islands that represent a range of geomorphological and ecological conditions present within the Virginia barrier island system—in 2021–2023 using a combination of field-based surveys and automated radio telemetry methods. Next, we used remotely sensed data to explore how climate-driven ecosystem state change on the Virginia barrier islands may be driving changes in the abundance and distribution of American oystercatcher nesting habitat across the barrier island system from 2004–2021. Finally, we evaluated the short-term outcomes of a field-based high school environmental education program using pre- and post-program surveys of students to assess how environmental education may promote changes in knowledge and public attitudes related to shorebird conservation initiatives in Virginia. Through routine surveys of nests and radio-marked chicks, we found that the cumulative probability of a nest surviving the incubation stage was greater than 90%, while the cumulative probability of a chick surviving from hatch to fledging was approximately 51%. Thus, chick survival, rather than nest survival, may be limiting reproductive success in the Virginia barrier islands. Flooding was a primary cause of nest loss (32% of failed nests), and storm-driven overwash in late April and early May forced peak nesting to shift later in the breeding season as breeding pairs renested, particularly in 2022. Despite ongoing management of mammalian predators through lethal removal, reproductive success still appears to be limited through the top-down effects of predation on both stages of American oystercatcher reproduction, as both nests (22% of failed nests) and chicks (46.4% of marked chicks) were lost from non-mammalian predators, including raptors (e.g., peregrine falcons [Falco peregrinus] and great horned owls [Bubo virginianus]) and Atlantic ghost crabs (Ocypode quadrata). Remotely sensed data provided an opportunity to investigate factors for which we lacked data collected in situ. Using aerial orthoimagery of the barrier islands collected by the National Agriculture Imagery Program (U.S. Department of Agriculture), we found that habitat abundance increased by 228.26 ha from 2004–2016, and then decreased by 124.38 ha from 2016–2021. Across the 2004-2021 timespan, abundance of American oystercatcher nesting habitat (defined as sites where the relative probability of nesting is ≥ 90%) was both temporally and spatially variable within the Virginia barrier island systems, with changes on only a few islands (e.g., Metompkin Island, Cedar Island, and Cobb Island) driving most of observed system-wide trends. We suggest that temporal variability may be a result of patterns of storminess along the Virginia coast 2004–2021, while spatial variability is likely due to localized differences in the geomorphological and ecological processes that control habitat availability, including sediment dynamics (e.g., sand erosion versus accretion), dune-building processes, and vegetative succession. Finally, we used an evaluation of The Nature Conservancy's field-based environmental education program for high school students as a case study to demonstrate the value of incorporating environmental education into a multidisciplinary conservation program. Using surveys that assessed components of environmental literacy—including knowledge of ecological concepts, feelings of connection and stewardship toward the local ecosystem, and behavioral intentions—we examined short-term educational outcomes for students who participated in a formal field trip to one of the Virginia barrier islands. By comparing responses on surveys delivered immediately before and immediately after the field trip, we found that participation in the field trip increased students' knowledge about barrier island ecosystems and sense of place attachment. Additionally, students self-reported positive environmental literacy outcomes on the post-trip assessment, including increased interest in scientific learning, increased likelihood of participating in stewardship behaviors, and increased intentions to participate in conservation behaviors. Given the pace at which ecosystems are changing in response to climate change and anthropogenic drivers, it is expected that the factors limiting American oystercatcher population growth will also continuously change. To protect against population declines, shorebird managers will need to continuously monitor for change. They will also need to consider the use of creative management approaches, including ecosystem-based management to address complex predation and climate threats, and environmental education and outreach programs to promote broad community support for conservation initiatives."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["The American oystercatcher is a large shorebird that nests along the United States Atlantic and Gulf coasts, from Maine to Texas. American oystercatchers have faced population declines due to threats from predators, changes in the amount and quality of their habitat, and conflicts with human communities that use similar coastal areas for recreation and commercial purposes. While efforts have been made to address these threats, new challenges to American oystercatcher conservation are emerging due to global climate change. The Virginia barrier islands are a mostly undeveloped coastal landscape located on the Atlantic coast of the Eastern Shore of Virginia, which includes Accomack County and Northampton County. The island system stretches for approximately 110 km (68 miles), providing important habitat for breeding American oystercatchers. Virginia has historically supported large numbers of breeding American oystercatchers, as well as high rates of reproductive success. However, since 2016, average yearly rates of American oystercatcher reproductive success in the Virginia barrier islands have been lower-than-expected despite continued management actions taken by The Nature Conservancy, Virginia Department of Wildlife Resources, United States Fish and Wildlife Service, and other state and federal government agencies. Biologists suspect that changes to American oystercatcher populations in Virginia may be, in part, a result of sea-level rise, different patterns of storm intensity and frequency, and warming temperatures. American oystercatcher reproduction occurs within two stages: (1) a nesting stage and (2) a chick-raising stage. Combined, these stages determine productivity, or the number of chicks that each breeding pair contributes to the population annually. We investigated the factors that contribute to American oystercatcher productivity in Virginia. First, we monitored nest and chick survival on two islands, Metompkin Island and Fisherman Island, in 2021–2023, so that we could calculate the probability of nests and chicks surviving each stage of reproduction and identify causes of nest loss or chick death. Next, we used aerial imagery collected by aircraft from 2004–2021 to answer the question: 'has the amount and location of nesting habitat changed for American oystercatchers in Virginia over the last eighteen years?' Finally, we examined one of The Nature Conservancy's school field trip programs on the Eastern Shore of Virginia to understand how much students learned during the trip, as well as how their feelings and attitudes about the Virginia barrier islands changed after participating in the trip. From monitoring American oystercatcher nests and chicks on Metompkin Island and Fisherman Island, we found that the probability of chicks surviving was lower than the probability of a nest surviving. Flooding from storms was an important cause of nest loss. Predation by other species of birds (such as peregrine falcons and great horned owls) and Atlantic ghost crabs was an important cause of both nest loss and chick deaths. We found that the amount and locations of American oystercatcher nesting habitat changed over time within the Virginia barrier islands. Additionally, each island had different patterns of change. For example, some islands, such as Metompkin Island, Cedar Island, and Cobb Island, gained a substantial amount of habitat during periods within 2004–2021, while other islands, such as Hog Island and Parramore Island, did not. Overall, the amount of American oystercatcher nesting habitat increased within the system by 228.26 ha (about 564 acres) from 2004–2016, and then decreased by 124.38 ha (about 307 acres) from 2016–2021. Finally, we used an evaluation of The Nature Conservancy's high school field trip program as an example of how environmental education programs can have a positive impact on conservation by increasing public knowledge about conservation issues and helping people feel attached to important natural resources. We delivered surveys to students before and after their field trip and asked them to answer questions related to their experience, what they learned, and how much they agreed with pre-written statements of feelings regarding the barrier islands and natural environment. When we compared students' responses from before and after the trip, we found that students knew more about barrier islands and felt a greater sense of attachment towards the barrier island system after returning from the field trip. Additionally, students reported that they were more interested in learning science and more interested in participating in conservation efforts after going on the field trip. As Virginia's barrier islands and its shorebirds continue to change due to changing climate, land managers such as The Nature Conservancy will need to continue to monitor and manage for changing predator populations, potentially restore habitats so that they are resilient to storms and rising sea levels, and continue to work closely with students and adults on the Eastern Shore of Virginia to create and enact the most sustainable conservation actions."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Shorebirds in a changing landscape: Assessing the top-down and bottom-up drivers of American oystercatcher (<i>Haematopus palliatus</i>) reproductive success in the Virginia barrier islands"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Karpanty, Sarah M."],"dc:contributor.committeemember":["Fraser, James D.","Chaves, Willandia A.","Wilke, Alexandra L.","Rogers, Haldre S."],"dc:contributor.department":["Fish and Wildlife Conservation"],"dc:creator":["Call, Mikayla Nicole"],"dc:date.accessioned":["2026-02-05T09:00:30Z"],"dc:date.available":["2026-02-05T09:00:30Z"],"dc:date.issued":["2026-02-04"],"dc:description.abstract":["Understanding the factors that affect population growth is a vital component of the conservation of imperiled species. On the United States (U.S.) Atlantic and Gulf coasts, the American oystercatcher (Haematopus palliatus) is largely managed within a conservation framework that aims to identify and manipulate factors that limit reproductive success. Coordinated research and monitoring across the species' range have identified several key threats to the survival of nests and chicks, including predation, habitat loss and degradation, and human disturbance. However, the relative importance of those threats can change, and new threats may emerge, as coastal ecosystems dynamically respond to global climate change. In the Virginia barrier islands, where American oystercatcher reproductive success has been historically high due to the widespread availability of undeveloped coastal habitat, declines in the average annual productivity rate of American oystercatchers since 2016 may signal evolving threats to reproduction. To provide insight into changing threats to American oystercatcher productivity in Virginia, and to inform adaptive management, we investigated the drivers of American oystercatcher reproductive success on the Virginia barrier islands. We considered three components of American oystercatcher conservation and management: (1) interactions between American oystercatchers, their conspecifics, and a complex predator community; (2) altered availability of nesting habitat due to climate-driven changes within barrier island ecosystem; and finally, (3) community support for widespread protection of the barrier island landscape and participation in conservation initiatives designed to protect breeding American oystercatchers, such as adhering to island access restrictions and recreation guidelines. We first investigated nest and chick survival on Metompkin Island and Fisherman Island—two islands that represent a range of geomorphological and ecological conditions present within the Virginia barrier island system—in 2021–2023 using a combination of field-based surveys and automated radio telemetry methods. Next, we used remotely sensed data to explore how climate-driven ecosystem state change on the Virginia barrier islands may be driving changes in the abundance and distribution of American oystercatcher nesting habitat across the barrier island system from 2004–2021. Finally, we evaluated the short-term outcomes of a field-based high school environmental education program using pre- and post-program surveys of students to assess how environmental education may promote changes in knowledge and public attitudes related to shorebird conservation initiatives in Virginia. Through routine surveys of nests and radio-marked chicks, we found that the cumulative probability of a nest surviving the incubation stage was greater than 90%, while the cumulative probability of a chick surviving from hatch to fledging was approximately 51%. Thus, chick survival, rather than nest survival, may be limiting reproductive success in the Virginia barrier islands. Flooding was a primary cause of nest loss (32% of failed nests), and storm-driven overwash in late April and early May forced peak nesting to shift later in the breeding season as breeding pairs renested, particularly in 2022. Despite ongoing management of mammalian predators through lethal removal, reproductive success still appears to be limited through the top-down effects of predation on both stages of American oystercatcher reproduction, as both nests (22% of failed nests) and chicks (46.4% of marked chicks) were lost from non-mammalian predators, including raptors (e.g., peregrine falcons [Falco peregrinus] and great horned owls [Bubo virginianus]) and Atlantic ghost crabs (Ocypode quadrata). Remotely sensed data provided an opportunity to investigate factors for which we lacked data collected in situ. Using aerial orthoimagery of the barrier islands collected by the National Agriculture Imagery Program (U.S. Department of Agriculture), we found that habitat abundance increased by 228.26 ha from 2004–2016, and then decreased by 124.38 ha from 2016–2021. Across the 2004-2021 timespan, abundance of American oystercatcher nesting habitat (defined as sites where the relative probability of nesting is ≥ 90%) was both temporally and spatially variable within the Virginia barrier island systems, with changes on only a few islands (e.g., Metompkin Island, Cedar Island, and Cobb Island) driving most of observed system-wide trends. We suggest that temporal variability may be a result of patterns of storminess along the Virginia coast 2004–2021, while spatial variability is likely due to localized differences in the geomorphological and ecological processes that control habitat availability, including sediment dynamics (e.g., sand erosion versus accretion), dune-building processes, and vegetative succession. Finally, we used an evaluation of The Nature Conservancy's field-based environmental education program for high school students as a case study to demonstrate the value of incorporating environmental education into a multidisciplinary conservation program. Using surveys that assessed components of environmental literacy—including knowledge of ecological concepts, feelings of connection and stewardship toward the local ecosystem, and behavioral intentions—we examined short-term educational outcomes for students who participated in a formal field trip to one of the Virginia barrier islands. By comparing responses on surveys delivered immediately before and immediately after the field trip, we found that participation in the field trip increased students' knowledge about barrier island ecosystems and sense of place attachment. Additionally, students self-reported positive environmental literacy outcomes on the post-trip assessment, including increased interest in scientific learning, increased likelihood of participating in stewardship behaviors, and increased intentions to participate in conservation behaviors. Given the pace at which ecosystems are changing in response to climate change and anthropogenic drivers, it is expected that the factors limiting American oystercatcher population growth will also continuously change. To protect against population declines, shorebird managers will need to continuously monitor for change. They will also need to consider the use of creative management approaches, including ecosystem-based management to address complex predation and climate threats, and environmental education and outreach programs to promote broad community support for conservation initiatives."],"dc:description.abstractgeneral":["The American oystercatcher is a large shorebird that nests along the United States Atlantic and Gulf coasts, from Maine to Texas. American oystercatchers have faced population declines due to threats from predators, changes in the amount and quality of their habitat, and conflicts with human communities that use similar coastal areas for recreation and commercial purposes. While efforts have been made to address these threats, new challenges to American oystercatcher conservation are emerging due to global climate change. The Virginia barrier islands are a mostly undeveloped coastal landscape located on the Atlantic coast of the Eastern Shore of Virginia, which includes Accomack County and Northampton County. The island system stretches for approximately 110 km (68 miles), providing important habitat for breeding American oystercatchers. Virginia has historically supported large numbers of breeding American oystercatchers, as well as high rates of reproductive success. However, since 2016, average yearly rates of American oystercatcher reproductive success in the Virginia barrier islands have been lower-than-expected despite continued management actions taken by The Nature Conservancy, Virginia Department of Wildlife Resources, United States Fish and Wildlife Service, and other state and federal government agencies. Biologists suspect that changes to American oystercatcher populations in Virginia may be, in part, a result of sea-level rise, different patterns of storm intensity and frequency, and warming temperatures. American oystercatcher reproduction occurs within two stages: (1) a nesting stage and (2) a chick-raising stage. Combined, these stages determine productivity, or the number of chicks that each breeding pair contributes to the population annually. We investigated the factors that contribute to American oystercatcher productivity in Virginia. First, we monitored nest and chick survival on two islands, Metompkin Island and Fisherman Island, in 2021–2023, so that we could calculate the probability of nests and chicks surviving each stage of reproduction and identify causes of nest loss or chick death. Next, we used aerial imagery collected by aircraft from 2004–2021 to answer the question: 'has the amount and location of nesting habitat changed for American oystercatchers in Virginia over the last eighteen years?' Finally, we examined one of The Nature Conservancy's school field trip programs on the Eastern Shore of Virginia to understand how much students learned during the trip, as well as how their feelings and attitudes about the Virginia barrier islands changed after participating in the trip. From monitoring American oystercatcher nests and chicks on Metompkin Island and Fisherman Island, we found that the probability of chicks surviving was lower than the probability of a nest surviving. Flooding from storms was an important cause of nest loss. Predation by other species of birds (such as peregrine falcons and great horned owls) and Atlantic ghost crabs was an important cause of both nest loss and chick deaths. We found that the amount and locations of American oystercatcher nesting habitat changed over time within the Virginia barrier islands. Additionally, each island had different patterns of change. For example, some islands, such as Metompkin Island, Cedar Island, and Cobb Island, gained a substantial amount of habitat during periods within 2004–2021, while other islands, such as Hog Island and Parramore Island, did not. Overall, the amount of American oystercatcher nesting habitat increased within the system by 228.26 ha (about 564 acres) from 2004–2016, and then decreased by 124.38 ha (about 307 acres) from 2016–2021. Finally, we used an evaluation of The Nature Conservancy's high school field trip program as an example of how environmental education programs can have a positive impact on conservation by increasing public knowledge about conservation issues and helping people feel attached to important natural resources. We delivered surveys to students before and after their field trip and asked them to answer questions related to their experience, what they learned, and how much they agreed with pre-written statements of feelings regarding the barrier islands and natural environment. When we compared students' responses from before and after the trip, we found that students knew more about barrier islands and felt a greater sense of attachment towards the barrier island system after returning from the field trip. Additionally, students reported that they were more interested in learning science and more interested in participating in conservation efforts after going on the field trip. As Virginia's barrier islands and its shorebirds continue to change due to changing climate, land managers such as The Nature Conservancy will need to continue to monitor and manage for changing predator populations, potentially restore habitats so that they are resilient to storms and rising sea levels, and continue to work closely with students and adults on the Eastern Shore of Virginia to create and enact the most sustainable conservation actions."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:45300"],"dc:identifier.uri":["https://hdl.handle.net/10919/141160"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["American oystercatcher","climate change","conservation","ecosystem change","environmental education","habitat","Haematopus palliatus","productivity","survival","Virginia"],"dc:title":["Shorebirds in a changing landscape: Assessing the top-down and bottom-up drivers of American oystercatcher (<i>Haematopus palliatus</i>) reproductive success in the Virginia barrier islands"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Fisheries and Wildlife Science"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:18Z"}