Ornithology Commons^™

Use Of Nest Web Cameras And Citizen Science To Quantify Osprey Prey Delivery Rate And Nest Success, Michael H. Academia, Harmony J. Dalgleish

Arts & Sciences Articles

Ospreys (Pandion haliaetus) are obligate piscivores and their nesting success depends on sufficient amounts of fish delivered to the nests during the breeding season. Nests are considered successful when pairs raise a minimum of one young to fledging or near-fledging age. Through web cameras and online broadcasts of Osprey nests, citizen scientists quantified daily number of fish deliveries, nest survival, and nest success. We received and analyzed curated data (one to seven seasons, 2014–2020) from citizen scientist groups representing 19 Osprey web cameras from four countries in North America and Europe. We compared the average and the coefficient …

Investigation Of Red-Cockaded Woodpeckers Within The Great Dismal Swamp National Wildlife Refuge: 2020 Report, B. D. Watts, C. Hines, L. Duval, B. J. Paxton

CCB Technical Reports

No abstract provided.

A Sonic Net Reduces Damage To Sunflower By Blackbirds (Icteridae): Implications For Broad-Scale Agriculture And Crop Establishment, Amanda K. Werrell, Page E. Klug, Romuald N. Lipcius, John P. Swaddle

VIMS Articles

Blackbirds, such as red-winged blackbirds (Agelaius phoeniceus), are notorious agricultural pests and damage crops at multiple stages of growth. Our aim was to test a novel deterrent, the use of sound designed to mask communication among birds (termed a “Sonic Net”), to deter blackbirds (Icteridae) from target areas of maturing sunflower crops. The Sonic Net masks communication of a target species by delivering “pink noise” that overlaps with the frequencies that the species uses for acoustic communication. If birds cannot hear predators or conspecific warning calls their perceived predation risk increases, and they relocate to an area with lower predation …

Linking Monitoring And Data Analysis To Predictions And Decisions For The Range-Wide Eastern Black Rail Status Assessment, Conor P. Mcgowan, Nicole F. Angeli, Whitney A. Beisler, Et Al., F. M. Smith, B. D. Watts

Arts & Sciences Articles

The US Fish and Wildlife Service (USFWS) has initiated a re-envisioned approach for providing decision makers with the best available science and synthesis of that information, called the Species Status Assessment (SSA), for endangered species decision making. The SSA report is a descriptive document that provides decision makers with an assessment of the current and pre - dicted future status of a species. These analyses support all manner of decisions under the US Endangered Species Act, such as listing, reclassification, and recovery planning. Novel scientific analysis and predictive modeling in SSAs could be an important part of rooting conservation decisions …

Virginia Peregrine Falcon Monitoring And Management Program: Year 2020 Report, B. D. Watts, M. U. Watts

CCB Technical Reports

The peregrine falcon (Falco peregrinus) was believed to be extirpated as a breeding species in Virginia by the early 1960s. An aggressive restoration program was initiated in 1978 that included the release of 115 captive-reared birds on the Coastal Plain (1978-1985) and 127 birds in the mountains (1985-1993). This program resulted in the first breeding of the modern era in 1982. Since this time, the population has proceeded through a rapid establishment phase followed by a consolidation phase. However, more than 95% of all breeding activity over the past 30 years has occurred on the Coastal Plain with very limited …

Investigation Of Red-Cockaded Woodpeckers In Virginia: Year 2019 Report, B. D. Watts, C. Hines, L. Duval, B. J. Paxton

CCB Technical Reports

The Virginia population of red-cockaded woodpeckers is the northernmost throughout the species range and has been in eminent danger of extinction for more than 30 years. The Piney Grove Preserve represents a nucleus for recovery in the state and the focus of a multi-organizational partnership designed to increase the population to a sustainable level. The partnership has executed a program of aggressive habitat management, cavity-tree management and woodpecker population monitoring and management that has resulted in a quadrupling of the breeding population since the early 2000s. During the 2019 breeding season, Piney Grove Preserve supported 15 potential breeding groups (including …

Long-Term Monitoring Of A Successful Recovery Program Of Peregrine Falcons In Virginia, B. D. Watts, Mitchell A. Byrd, E. K. Mojica, S. Padgett, S. R. Harding, C. A. Koppie

Arts & Sciences Articles

The Peregrine Falcon (Falco peregrinus anatum) was believed to be extirpated as a breeding species in Virginia by the early 1960s. An aggressive restoration program was initiated in 1978 that involved the release of captive-reared birds totaling 115 on the Coastal Plain (1978–1985) and 127 in the Mountain physiographic region (1985–1993). The first occupied territory was established and the first breeding attempt was documented in 1979 and 1982, respectively. We have monitored the size, distribution, reproductive rate, and substrate use of the resulting breeding population (1979–2016). The population proceeded through an establishment phase (1979–1993) driven by releases with an average …

Assessment Of Black Rail Status In Georgia, Interim Report: Summer 2018, B. D. Watts, B. J. Paxton, F. M. Smith

CCB Technical Reports

No abstract provided.

Exposure Of Bald Eagle Nestlings To Contaminants On National Park Service Lands Within The Chesapeake Bay, Interim Report: Fall 2017, B. D. Watts, B. J. Paxton, M. L. Pitts

CCB Technical Reports

No abstract provided.

Mapping Bald Eagle Activity Shadows Around Communal Roosts, B. D. Watts, Courtney Turrin

Arts & Sciences Articles

We assessed diurnal activity patterns associated with communal roosts (n = 26) by tracking nonbreeding bald eagles (Haliaeetus leucocephalus; n = 58) within the upper Chesapeake Bay, USA, 2008-2013. We used daytime locations (n = 54,165) to map activity shadows (using home range analytics, 90% kernel) around communal roosts, to evaluate the spatial structure and to delineate diurnal activity centers. We overlaid a range (100-3,200 m) of buffers around the perimeter of each roost to estimate the benefits of management scenarios in extending protection to daytime activities. Activity shadows around roosts varied from 1.5 km(2) to 116 km(2) ((x) over …

Blood Mercury Levels Of Zebra Finches Are Heritable: Implications For The Evolution Of Mercury Resistance, Kenton A. Buck, Claire W. Varian-Ramos, Daniel A. Cristol, John P. Swaddle

Arts & Sciences Articles

Mercury is a ubiquitous metal contaminant that negatively impacts reproduction of wildlife and has many other sub-lethal effects. Songbirds are sensitive bioindicators of mercury toxicity and may suffer population declines as a result of mercury pollution. Current predictions of mercury accumulation and biomagnification often overlook possible genetic variation in mercury uptake and elimination within species and the potential for evolution in affected populations. We conducted a study of dietary mercury exposure in a model songbird species, maintaining a breeding population of zebra finches (Taeniopygia guttata) on standardized diets ranging from 0.0–2.4 μg/g methylmercury. We applied a quantitative genetics …

Utilization Probability Map For Migrating Bald Eagles In Northeastern North America: A Tool For Siting Wind Energy Facilities And Other Flight Hazards, Elizabeth K. Mojica, B. D. Watts, Courtney L. Turrin

Arts & Sciences Articles

Collisions with anthropogenic structures are a significant and well documented source of mortality for avian species worldwide. The bald eagle (Haliaeetus leucocephalus) is known to be vulnerable to collision with wind turbines and federal wind energy guidelines include an eagle risk assessment for new projects. To address the need for risk assessment, in this study, we 1) identified areas of northeastern North America utilized by migrating bald eagles, and 2) compared these with high wind-potential areas to identify potential risk of bald eagle collision with wind turbines. We captured and marked 17 resident and migrant bald eagles in the northern …

A Sonic Net Excludes Birds From An Airfield: Implications For Reducing Bird Strike And Crop Losses, John P. Swaddle, Dana L. Moseley, Mark H. Hinders, Elizabeth P. Smith

Arts & Sciences Articles

Collisions between birds and aircraft cause billions of dollars of damages annually to civil, commercial, and military aviation. Yet technology to reduce bird strike is not generally effective, especially over longer time periods. Previous information from our lab indicated that filling an area with acoustic noise, which masks important communication channels for birds, can displace European Starlings (Sturnus vulgaris) from food sources. Here we deployed a spatially controlled noise (termed a “sonic net”), designed to overlap with the frequency range of bird vocalizations, at an airfield. By conducting point counts, we monitored the presence of birds for four …

Seasonal Variation In Space Use By Nonbreeding Bald Eagles Within The Upper Chesapeake Bay, B. D. Watts, Elizabeth K. Mojica, B. J. Paxton

Arts & Sciences Articles

Access to food resources is essential to self-maintenance and reproduction and, for species of conservation concern, foraging areas are considered critical habitat. Human disturbance is an important factor restricting access to prey resources for Bald Eagles (Haliaeetus leucocephalus) and guidelines in the Chesapeake Bay have been developed to mitigate its impact. However, our ability to implement such guidelines has been limited by a lack of information on important foraging areas. We used Brownian bridge movement modeling to develop a population-wide utilization probability surface for Bald Eagles along shorelines within the upper Chesapeake Bay. We used locations (n …

Landfill Use By Bald Eagles In The Chesapeake Bay Region, Courtney Turrin, B. D. Watts, Elizabeth K. Mojica

Arts & Sciences Articles

We examined patterns in the use of landfills (rubbish dumps) in the Chesapeake Bay by Bald Eagles (Haliaeetus leucocephalus). Sites of solid waste landfills (n  =  72) were located using state databases. Satellite tracking data from 64 eagles were used to track eagle movements hourly during daylight and once at midnight to determine roosting locations (2007–2012). Landfill use varied significantly with age class, with hatch-year birds using landfills six times more often than adults and twice as often as third- and fourth-year birds. Hatch-year birds spent significantly more time at landfills than expected based on landfill area …

Nest Guarding In Chesapeake Bay Bald Eagles, Courtney Turrin, B. D. Watts

Arts & Sciences Articles

As Bald Eagle (Haliaeetus leucocephalus) populations approach carrying capacity in the Chesapeake Bay, competition for breeding territories appears to be intensifying. Frequent territorial interactions may force breeders to adjust nest-guarding behavior. We examined nest-guarding behaviors at active Bald Eagle nests in the lower Chesapeake Bay during the nesting season (2012 and 2013). Guarding coverage was 13.7 ± 4.2% of total observation time during the pre-laying period, 6.8 ± 2.2% of observation time in the incubation period, and 26.3 ± 3.2% of observation time in the nestling period. Females were present in the nest area for 80.0 ± 2.7% …

Intraspecific Intrusion At Bald Eagle Nests, Courtney Turrin, B. D. Watts

Arts & Sciences Articles

Competition for nesting territory has been shown to act as a density-dependent feedback mechanism influencing population growth rate. However, little is known about the nature of territorial interactions between established breeders and floaters. We examined territorial intrusion rates and associated behaviours at active Bald Eagle Haliaeetus leucocephalus nests in the lower Chesapeake Bay in 2012 and 2013. The average intrusion rate experienced at study nests during the reproductive period was 0.28 ± 0.32 intrusions/h. Variance in intrusion rate was high and there was no apparent predictive pattern to these events. Juvenile intrusions occurred closer to the nest than adult intrusions, …

Mercury Reduces Avian Reproductive Success And Imposes Selection: An Experimental Study With Adult- Or Lifetime-Exposure In Zebra Finch, Claire W. Varian-Ramos, John P. Swaddle, Daniel A. Cristol

Arts & Sciences Articles

Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. …

Recovery Of Breeding Bald Eagles On Aberdeen Proving Ground, B. D. Watts

Arts & Sciences Articles

We conducted annual aerial surveys (1991-2011) for breeding Bald Eagles (Haliaeetus leucocephalus) within Aberdeen Proving Ground (APG), a 350-km2 military installation located along the northwestern shoreline of the upper Chesapeake Bay in Maryland. The population increased exponentially from 1 pair in 1977 to 58 pairs in 2011 with an average doubling time of 5.8 years. This rate was higher than that documented for the broader Chesapeake Bay and is comparable to the highest reported throughout the species range. Annual population increase was highly variable and exhibited no indication of any systematic decline. A total of 646 chicks were produced from …

Projected Hg Dietary Exposure Of 3 Bird Species Nesting On A Contaminated Floodplain (South River, Virginia, Usa), Jc Wang, Mc Newman

VIMS Articles

Dietary Hg exposure was modeled for Carolina wren (Thryothorus ludovicianus), Eastern song sparrow (Melospiza melodia), and Eastern screech owl (Otus asio) nesting on the contaminated South River floodplain (Virginia, USA). Parameterization of Monte-Carlo models required formal expert elicitation to define bird body weight and feeding ecology characteristics because specific information was either unavailable in the published literature or too difficult to collect reliably by field survey. Mercury concentrations and weights for candidate food items were obtained directly by field survey. Simulations predicted the probability that an adult bird during breeding season would ingest specific amounts of Hg during daily foraging …

Anthropogenic Noise Is Associated With Reductions In The Productivity Of Breeding Eastern Bluebirds (Sialia Sialis), Caitlin R. Kight, Margaret S. Saha, John P. Swaddle

Arts & Sciences Articles

Although previous studies have related variations in environmental noise levels with alterations in communication behaviors of birds, little work has investigated the potential long-term implications of living or breeding in noisy habitats. However, noise has the potential to reduce fitness, both directly (because it is a physiological stressor) and indirectly (by masking important vocalizations and/or leading to behavioral changes). Here, we quantified acoustic conditions in active breeding territories of male Eastern Bluebirds (Sialia sialis). Simultaneously, we measured four fitness indicators: cuckoldry rates, brood growth rate and condition, and number of fledglings produced (i.e., productivity). Increases in environmental noise …

Constraints On Acoustic Signaling Among Birds Breeding In Secondary Cavities: The Effects Of Weather, Cavity Material, And Noise On Sound Propagation, John P. Swaddle, Caitlin R. Kight, Saji Perera, Eduardo Davila-Reyes, Shena Sikora

Arts & Sciences Articles

Increasing evidence suggests that anthropogenic noise from urbanization affects animal acoustic communication. We investigated whether the begging calls of nestling Eastern Bluebirds (Sialia sialis) varied along a disturbance gradient of ambient noise. Contrary to our prediction and the results of a previous study of nestling Tree Swallows (Tachycineta bicolor), we found that nestling Eastern Bluebirds did not increase the amplitude or structural characteristics—including frequency, rate, and duration—of their vocalizations in response to ambient noise. However, we found that prevalent temperature and humidity conditions attenuated begging calls. Specifically, in warmer, more humid weather, vocalizations of nestling Eastern …

Acoustic Space Is Affected By Anthropogenic Habitat Features: Implications For Avian Vocal Communication, Caitlin R. Kight, Mark H. Hinders, John P. Swaddle

Arts & Sciences Articles

Human-altered landscapes often include structural features, such as higher levels of impervious surface cover (ISC) and less vegetation, that are likely to affect the transmission of avian vocalizations. We investigated the relationships between human habitat modifications and signal transmission by measuring four acoustic parameters—persistence, reverberation, and signal-to-noise ratio (SNR) of broadcast tones, as well as absolute ambient noise level—in each of 39 avian breeding territories across an anthropogenic disturbance gradient. Using a geographic information system, we quantified the amounts of different habitat features (e.g., ISC, grass, trees) at each site; a principal component analysis was used to identify which of …

Reproductive Success Of Eastern Bluebirds (Siala Sialis) On Suburban Golf Courses, Kerri L. Cornell, Caitlin R. Kight, Ryan B. Burdge, Alex R. Gunderson, Joanna K. Hubbard, Allyson K. Jackson, Joshua E. Leclerc, Marie L. Pitts, John P. Swaddle, Daniel A. Cristol

Arts & Sciences Articles

Understanding the role of green space in urban—suburban landscapes is becoming critical for bird conservation because of rampant habitat loss and conversion. Although not natural habitat, golf courses could play a role in bird conservation if they support breeding populations of some native species, yet scientists remain skeptical. In 2003–2009, we measured reproduction of Eastern Bluebirds (Siala sialis) in Virginia on golf courses and surrounding reference habitats, of the type that would have been present had golf courses not been developed on these sites (e.g., recreational parks, cemeteries, agriculture land, and college campus). We monitored >650 nest boxes …

Distribution, Habitat Characteristics, Prey Abundance And Diet Of Surf Scoters (Melanitta Perspicillata) And Long-Tailed Ducks (Clangula Hyemalis) In Polyhaline Wintering Habitats In The Mid-Atlantic Region: A Comparison Of Shallow Coastal Lagoons And Chesapeake Bay Environs, Paige G. Ross, Mark W. Luckenbach

Reports

To the best of our knowledge there are no published data on sea duck winter habitat use in the higher salinity portion of the lower Chesapeake Bay or in adjacent coastal bays along the Atlantic margin of the Delmarva (Delaware, Maryland, Virginia) peninsula. Within these regions both SUSC and LTDU have been observed in shallow water environments (Ross, pers. obs.), yet little is known about their habitat use or feeding habits in these areas. Importantly, these two adjacent areas, which are separated by as little as 20 km, differ in several key environmental components.

In this study we documented the …

Whimbrel Tracked With Satellite Transmitter On Migratory Flight Across North America, B. D. Watts, B. R. Truitt, F. M. Smith, E. K. Mojica, Et Al.

Arts & Sciences Articles

"Two disjunct breeding populations of Whimbrel Numenius phaeopus have been described in the western hemisphere (American Ornithologists’ Union 1983). The western population breeds in portions of Alaska and across the Yukon and Northwest Territories of Canada while the eastern population breeds west and south of Hudson Bay (Skeel & Mallory 1996). Most of what we believe we know about the migratory pathways of these populations has been pieced together from circumstantial evidence gleaned from decades of field observations (Skeel & Mallory 1996, Taverner 1942). The populations have been thought to have separate migratory routes with little mixing where the western …

A Check List Of The Biota Of Lower Chesapeake Bay : With Inclusions From The Upper Bay And The Virginian Sea, Marvin L. Wass

Reports

The biota of Chesapeake Bay seems generally less known than that of New England and much of our West Coast. The present work attempts to mollify this discrepancy. The compilation has been revised and expanded to include plants and vertebrates. Inclusion of creatures not strictly aquatic but which may occasionally found their areas flooded by tidal waters has necessitated subjective declsions of limitation.

Includes:

• Lower Plants
• Wetland and Dune Plants
• Phylum Protozoa
• Free-living Invertebrates (except Protozoa)
• Fishes of Chesapeake Bay and the Adjacent Coastal Plain
• Herptiles of the Maryland and Virginia
• Coastal Plain Birds Dependent on Open Water or Wetlands …

The Aerodynamics Of Flapping Birdflight, Carol Coughlin, Virginia Institute Of Marine Science

Reports

No abstract provided.

A Mathematical Analysis Of The Dynamic Soaring Flight Of The Albatross With Ecological Interpretations, Carol Coughlin

Reports

The capability of flight plays a central role in the lives of most birds. Indeed, the existing morphological and ecological characteristics of many species are almost entirely dictated by the aerodynamic requirements of the highly developed flight modes they have acquired through evolutional specialization. In the case of such species, a clear understanding of the aerodynamic mechanisms underlying the particular flight modes can often provide a lucid insight into the basic physical relationships which govern a bird's characteristic activities and behavior.

This aerodynamic approach to the study of avian ecology is particularly useful in the case of soaring birds, where …