Status and distribution of colonial waterbirds in coastal Virginia: 2008 breeding season

Colonial waterbirds are highly visible components of coastal avifaunas that share the unusual characteristic of nesting in dense assemblages. One consequence of having large portions of populations nesting in few locations is that even restricted disturbance may have profound consequences on a population level. Development of conservation strategies for these sensitive species requires current status and distribution information. During the breeding seasons of 1993 and 2003, a comprehensive assessment of the colonial waterbird community in coastal Virginia was conducted with the purpose of providing information needed for strategic management and future trend analysis. During the spring of 2007, a decision was made by a consortium of partners to conduct a third assessment on the 5th anniversary of the 2003 survey. Due to funding constraints, the 2008 survey did not cover the widely dispersed colonies of Great Blue Herons and Great Egrets in the interior of the western shore or within the portion of the Coastal Plain south of the James River. For this reason, the 2008 survey produced comparable population assessments for 22 of the 24 colonial waterbird species known to nest in Virginia. Nearly 550 surveys were conducted of 250 colonies during the breeding season of 2008. Colonies supported an estimated 60,758 breeding pairs of 24 species. Gulls were the most abundant group with more than 40,000 breeding pairs. Terns and waders accounted for 9,455 and 4,763 pairs respectively. Laughing gulls were several times more abundant than any other species and represented 61% of the total waterbird community. The barrier island/lagoon system of the Eastern Shore was the most important region for the majority of colonial species encountered. This region supported 20 of the 23 species evaluated during the survey and accounted for greater than 74% and 70% of all breeding pairs and colonies, respectively. For 15 of the 23 species, the region supported more than 50% of the known coastal population. The colonial waterbird community in coastal Virginia that was assessed during this survey (all species except Great Blue Heron and Great Egret) declined by 28.9% during the 15 years between 1993 and 2004 (Table 3). Population estimates for 14 of 22 species assessed declined since 1993 and 11 of these have declined since the 2003 survey. Declines varied considerably between species with 10 species declining more than 40% and 4 species declining more than 70%. Cattle Egrets showed the highest loss rate, declining from an estimated 1,459 to only 120 pairs. Eight species increased between 1993 and 2008. Dramatic expansions were documented for White Ibis, Great Black-backed Gull, Double-crested Cormorant, and Brown Pelican. The seaside of the Delmarva Peninsula is the most important region for colonial waterbirds in Virginia. Despite heroic efforts to manage several species, declines have not been abated. Collectively, the waterbird community has declined 33% between 1993 and 2008. Snowy Egret, Tricolored Heron, Cattle Egret, Green Heron, Yellow-crowned Night Heron, Glossy Ibis, Herring Gull, Laughing Gull, Gull-billed Tern, Royal Tern, Forster’s Tern, Common Tern, and Black Skimmer all showed a consistent decline across this period. Only species that have colonized the area since 1970 including White Ibis, Great Black-backed Gull, Doublecrested Cormorant, and Brown Pelican have exhibited consistent increases. The ecological differences between species showing declines suggest a system-wide problem that is greater than the mammalian predators that have been the focus of recent management actions

Investigation of grassland/shrubland migrants on the Lower Delmarva Peninsula

Intro and Objectives: Concerns about declines in many North American bird populations have recently increased within both the scientific community and the general populous. To a large degree, this concern has been focused on neotropical migrants. In particular, neotropical migrant passerines that breed within forested habitats have received a great deal of attention from research and conservation organizations. However, results from the annual U.S. Fish and Wildlife Service’s breeding bird survey suggest that species associated with grasslands and or shrublands have experienced annual population declines that in many cases are greater than those experienced by forest-dwelling birds (Robbins et al. 1986 Askins 1993). Declines of grassland species are particularly evident in northeastern North America where habitat loss due to secondary succession and urbanization has been dramatic. Results from two long-term studies have shown that several species that depend on early successional habitats have experienced marked declines over the past two decades (Hagan et al. 1992). Many of these declining species migrate either to the tropics or to the southeastern U.S. and depend on open habitats for rest and refueling. Open farmlands have declined by nearly 80% within the mid-Atlantic region since the 1940’s (U.S. Dept. of Commerce 1981). Dramatic changes in land use practices over this same time period have left remaining open habitat less suitable for use by grassland species (Millenbath et al. 1996). Each autumn large numbers migrant landbirds, reluctant to cross the Chesapeake Bay, are concentrated on the lower Delmarva Peninsula. To date, most of the research devoted to passerine migration on the lower Delmarva Peninsula has focused on neotropical migrants that depend on forested habitats (Watts and Mabey 1993, 1994). Relatively little attention has been given to species that require open habitats. The Eastern Shore of Virginia National Wildlife Refuge contains some of the most significant stopover habitat for open-habitat migrants within the mid-Atlantic region. Information is needed on the stopover ecology and habitat requirements of these species so that they may be incorporated into existing and developing management plans for the refuge and other landholders. The objectives of this study were to investigate the use of grassland/shrubland habitats during the late period of fall migration. Information gathered will be used to determine the abundance and time of movement for open-habitat migrants on the lower Delmarva Peninsula

An assessment of the Bald Eagle and Great Blue Heron breeding populations along High Rock, Tuckertown, Narrows, and Falls Reservoirs in central North Carolina: 2018 breeding season.

The objectives of the annual eagle survey on the Yadkin Project reservoirs are: 1) To document the status, distribution and productivity of nesting pairs in association with the Yadkin reservoirs and associated river corridors. 2) To increase our understanding of Bald Eagle natural history in interior regions of North Carolina. 3) To determine the status and distribution of breeding Great Blue Herons (and associated Great Egrets and Double-crested Cormorants) within the Yadkin Project reservoirs

Bird surveys of Lee and Hill Marshes on the Pamunkey River: Possible affects of sea-level rise on marsh bird communities

Tidal wetlands are important to coastal ecosystems. They provide flood protection, erosion control and improve water quality. Tidal wetlands also provide essential habitats for numerous species of wildlife, many of which rely on these marsh habitats as sites for breeding and development. Historical wetland surveys indicate that as much as half of the marshes present along the Atlantic and gulf coasts in 1900 have disappeared. While direct human impact has long been a cause of wetland loss, sea level rise is quickly becoming a leading source of current and anticipated wetland losses. Brackish marshes, situated on the transition zone between tidal freshwater and oligohaline marshes, may be most at risk from the effects of sea level rise. Lee and Hill marshes, located near the mouth of the Pamunkey River, are two of the largest brackish marshes remaining in Virginia. Due to the isolated and inaccessible nature of many brackish marshes within the Chesapeake Bay, little information exists on their associated bird communities. The objectives of this study were to provide information on the species presence, distribution, and abundance of birds within Lee and Hill marshes during the breeding and winter season. An additional objective was to quantify the relationship between birds and the dominant vegetation types within these marshes. Thirty-two survey points were established within Lee and Hill Marshes and associated with one of three habitat types (Peltandra mix, Spartina cynosuroides, and Phragmites sp.). Birds were surveyed 3 times at each point during the breeding season of 2001, and 3 times during the late winter of 2002. Results from surveys were used to calculate species richness and density estimates for habitat types. A total of 3,510 detections of 38 species were made during both survey seasons within all habitat types. During the summer surveys 1,711 observations were made of 19 species. Winter surveys resulted in 1,799 detections of 26 species. Some differences were noted in species richness values and densities between habitat types. This information will be useful in monitoring and projecting changes in the bird populations of these marshes in the event of changes to the vegetation community due to sea level rise or other factors

The influence of thorny elaeagnus on automobile-induced bird mortality

Thorny Elaeagnus (Elaeagnus pungens) has been used throughout the southeastern United States as a highway median plant for more than 30 years. Native to Asia, elaeagnus has a number of characteristics that make it ideal for roadside planting. The plant is a heat and drought resistant, evergreen shrub that is fast growing. Because elaeagnus forms a dense, tall hedgerow, it provides an effective divider between opposing lanes of traffic. In the spring of 1999, representatives of the U.S. Fish and Wildlife Service collected 459 dead birds along discreet sections of highway near Richmond, Virginia. Roadway sections were adjacent to median plantings of thorny elaeagnus containing dense fruit crops. The objective of this field study was to investigate the possible relationship between median plantings and bird mortality. A simple one-way study design was used with median condition as the single factor. Three median conditions were examined including (1) no median planting, (2) elaeagnus without fruit, and (3) elaeagnus with fruit. Replicate roadway segments containing desired median conditions were surveyed 3 times/week for live and dead birds from mid-March to mid-May. The presence of ripe elaeagnus fruit had a significant influence on both the use of medians by birds and bird mortality. Of 1,270 live birds observed along the roadways, 1,200 were detected along plantings that contained dense fruit crops. These same roadway sections accounted for 78 of 80 dead birds collected. Bird density and mortality within medians that supported shrubs without fruit were not appreciably higher than control medians that contained only grass. Additionally, the seasonal timing of median use and mortality was found to correspond to the peak availability of ripe fruit. Finally, the composition of live and dead birds was dominated by fruit-eating species. The results of the study suggest that birds are attracted to elaeagnus fruit within median plantings and that mortality is a consequence of this attraction. The juxtaposition of dense fruit crops with high-traffic areas seems to result in elevated bird mortality. Birds are being struck and killed by oncoming traffic as they fly across roadways to reach fruit crops

The response of bird mortality to experimental removal of thorny elaeagnus within roadway medians

Research within the mid-Atlantic region have shown that the majority of neotropical migrants utilizing the outer coastal plain as a migration route are young of the year, and that many are not replenishing fat reserves during times of stop-over. Research has also shown that foraging rates are higher in deciduous habitats than in pine habitats. The general composition of the forests of the mid-Atlantic coastal plain shift from pine dominated on the outer coastal plain to hardwood dominated along the fall line of the inner coastal plain. Studies were initiated to determine if these hardwood dominated habitats are better stop-over habitats than the pine dominated forests of the coastal fringe, and to determine differences in age ratios, condition, foraging rates, and energy gains of selected species of neotropical migrants using these habitats. Study sites were established within the outer and inner coastal plain to assess the availability of prey items, perform foraging observations, and capture birds for evaluation of age and condition. Habitats on the inner coastal plain seem to be superior to the pine habitats of the outer coastal plain. While sites on the outer coastal plain produced more arthropods over all, sites on the inner coastal plain had greater numbers of arthropods associated with foliage, where migrants were observed foraging most often. Greater percentages of after hatch year birds were captured on the inner coastal plain, and although new birds captured on the outer coastal plain initially carried more fat and had higher masses, recapture data show that during stop-over birds tended to gain mass on the inner coastal plain and lose mass on the outer coastal plain. Black-throated blue Warblers on the inner coastal plain were the only birds analyzed that were ingesting sufficient numbers of prey items to meet their daily metabolic needs and produce fat. The results suggest that the hardwood dominated forest of the inner coastal plain contain superior stop-over habitats for neotropical migrants than the pine dominated forests of the outer coastal plain

Status and Distribution of Colonial Waterbirds in Coastal Virginia: 2013 Breeding Season

Colonial waterbirds are highly visible components of coastal avifauna that share the unusual characteristic of nesting in dense assemblages. One consequence of having large portions of populations nesting in few locations is that even restricted disturbance may have profound consequences on a population level. Development of conservation strategies for these sensitive species requires current status and distribution information. In the fall of 1992, a consortium of agencies and individuals agreed that a comprehensive monitoring program for the Virginia colonial waterbird community was needed and that assessments should be made on decadal intervals for trend analyses. Surveys were conducted during the breeding seasons of 1993 and 2003. The 2013 survey reported here is the third in the time series. All of these surveys have systematically covered all 24 species of colonial waterbirds throughout the Coastal Plain province of Virginia. Nearly 800 surveys were conducted of 496 waterbird colonies during the breeding season of 2013. Colonies supported an estimated 60,604 breeding pairs of 24 species. Gulls were the most abundant group with more than 28,000 breeding pairs. Waders and terns accounted for 14,117 and 10,993 pairs respectively. Laughing gulls were the most abundant species representing nearly 40% of the total waterbird community. The barrier island/lagoon system of the Eastern Shore was the most important region for the majority of colonial species encountered. In 2013, this region supported 23 of the 24 species evaluated. The Eastern Shore accounted for 54.7% and 27.2% of all breeding pairs and colonies respectively. For 15 of the 24 species, the region supported more than 50% of the known coastal population. The colonial waterbird community in coastal Virginia declined by 36.2% in the years between 1993 and 2013. Population estimates for 19 (79%) of 24 species assessed declined between 1993 and 2013. Declines varied considerably between species with 10 species declining more than 40% and 5 species declining more than 60%. Cattle Egrets showed the highest loss rate (-96.2%), declining from an estimated 1,459 to only 56 pairs. Eight species increased between 1993 and 2008. Dramatic expansions were documented for White Ibis, Great Black-backed Gull, Double-crested Cormorant, and Brown Pelican. Over the past 20 years, three major forces appear to be shaping the colonial waterbird community in Virginia. These include 1) regional shifts in population centers that are driving population increases in Virginia, 2) habitat degradation related to sea-level rise, and 3) recovery of the bald eagle population. With the exception of Great Egrets, all species that have increased over the past 20 years have experienced ongoing range expansions and are riding a population wave that is progressing through Virginia. This includes Great Black-backed Gull, Double-crested Cormorant, Brown Pelican, and White Ibis. Most of the decline in medium-sized waders is being driven by habitat loss related to erosion of islands. This erosion results from sea-level rise, is ongoing and represents a significant threat to these populations. Several ground-nesting seabirds are likely more directly impacted by increased restriction in viable habitat and demographic impacts related to frequent flooding. The most notable example is the Laughing Gull that has experienced a catastrophic decline in just 10 years. Finally, the dramatic recovery of the Bald Eagle within the Chesapeake Bay has resulted in the species breeding within more than 25% of large wader colonies and may be responsible for the fragmentation of historic colonies and the beginnings of a population decline. This factor may ultimately impact other populations in the future

Assessment of potential impacts to avian species from a proposed 750 foot guyed tower at NASA’s Goddard Space Flight Center’s Wallops Flight Facility on Wallops Island, Virginia

• NASA has proposed A 750 foot guyed instrumentation tower to be constructed on Wallops Island, VA at one of two locations. • Wallops Island is embedded within a critical location along the Atlantic Flyway that supports millions of avian species annually, many of which are of conservation concern. Since this tower has the potential to act as a collision hazard for birds, NASA has requested a synthesis of existing information on the species exposure and relative vulnerability to the proposed construction. • The proposed tower site and its alternative are relatively identical with respect to location from shoreline or other natural habitats use by birds and are only separated by 2,300 feet. There is no indication from known information that one site or the other poses any greater or lesser risk to collision by birds. • While the construction of an instrumentation tower on Wallops Island may result in bird mortality collisions, a central question from a population perspective, is not how many individuals would be killed annually but if the focal population would be able to sustain the mortality incurred and still reach conservation and management objectives. • Information required to make a full assessment on an expected mortality rate from the proposed tower does not exist. Information required for this type of assessment would include full understanding of the distribution of migrant corridors, breeding populations, winter populations and the flight altitudes of many species. In many cases this is only possible through post-construction monitoring. Because this monitoring data does not exist, the best assessment, based on the information available, was undertaken to provide relative levels of risk based on characteristics of broad population overlap with the tower site and species flight and behavioral characteristics