Ornithology Commons^™

The Effects Of Chemical Secretions By Millipedes On Anting Behaviour In Birds And Other Animals, Theo Fraser

2023 REYES Proceedings

Birds perform a behavior known as anting in which they actively rub ants in their feathers or allow ants to crawl over their bodies. Several hypotheses have been proposed to explain this behavior, but no one hypothesis can account for all cases of anting that have been observed. Anting behavior has been recorded in species other than birds including primates, and substances other than ants such as millipedes may be used. This paper explores the use of millipedes in anting by birds, capuchin monkeys and lemurs. The three hypotheses supported by these studies include 1) anting serves as food preparation …

Can The Food Preparation Hypothesis Account For Anting Behavior In Birds?, Ella Brady

2023 REYES Proceedings

This report discusses the food preparation hypothesis, one of several proposed hypotheses to explain anting behavior in birds. A brief review of the theory’s history and development, as well as an assessment of evidence for and against such a function of anting, is provided. Although there are indeed experimental data supporting food preparation as the purpose of anting behavior, there is also conflicting evidence which complicates the theory. Ultimately, it is suggested that food preparation is a secondary function of anting – a pleasant but latent “side effect” achieved alongside the behavior’s primary purpose, which is still unknown.

Hypotheses Related To Anting By Birds, Helena Flores

2023 REYES Proceedings

“Anting” is a widespread behavior among bird species and mammals. Due to the various characteristics of this behavior, numerous hypotheses have been proposed to explain it. This behavior can be classified as “active”, in which birds take a bill full of ants and rub them into their feathers, or “passive” when birds let ants wander through their plumage. The hypotheses state that anting may be performed as an (1) antiparasitic behavior, for (2) feather grooming, as a way of (3) food preparation or to (4) decrease skin irritation during molt, even as a (5) sensory stimulation tool. This review compiles …

Population Dynamics And Dispersal Coalitions In The Cooperatively Breeding Acorn Woodpecker, Natasha Hagemeyer

Biological Sciences Theses & Dissertations

Dispersal is a critical life-stage with consequences not only for the individual, but for population dynamics and thus the fate of the whole species. The creation of dispersal coalitions can lead to complex outcomes and affect how changes in abundance occur on the landscape. I examined population dynamics and dispersal coalitions in a population of cooperatively breeding acorn woodpeckers in central California, USA. Using a 34-year dataset on occupancy and abundance, I determined that increases in abundance were determined by dispersal to new locations. This resulted in increased occupancy, rather than increases in group size and larger coalitions. I then …

Artificial Perches As A Technique For Enhancing Tropical Forest Restoration: A Case Study From The Dominican Republic, Spencer Schubert, Ally S. Lahey, Ashley R. Weisman, Eric L. Walters

College of Sciences Posters

Recovering secondary forests on degraded agricultural lands represents a promising opportunity to offset global carbon emissions as well as increasing local biodiversity and ecosystem services. In the insular tropical forests of the Caribbean, frugivorous birds are the primary seed dispersers for most native woody plants and have a large influence on regeneration dynamics during forest succession. In 2017, we initiated an experimental forest restoration program incorporating artificial perches on private farms within the Rio Yaque del Norte watershed in La Vega province, Dominican Republic. Five restoration plots (0.15–0.25 ha) were constructed in pastures near deforested streams. In each plot, 6-12 …

The Effects Of Hackberry Psyllids On Refueling Migratory Songbirds And Autumnal Seed Rain, Chance H. Hines

Biological Sciences Theses & Dissertations

Hackberry psyllids (Pachypsylla sp) are a galling insect native to North America’s hackberry trees (Celtis sp). Hackberry leaf-galling psyllids are ephemerally abundant during autumn, a period of time when migratory songbirds are traveling from their breeding areas in temperate North America south to their winter ranges. These migrations are energetically taxing and many songbirds fuel their journey with resources like insects and fruits. I captured birds with mist nets, observed foraging behaviors, and captured avian-dispersed fleshy fruit seeds (hereafter, seed rain) rain during the autumn of 2016 and 2017 to determine how hackberry psyllids, an ephemerally …

Wandering Woodpeckers: Foray Behavior In A Social Bird, Sahas Barve, Natasha D. G. Hagemeyer, Russell E. Winter, Samuel D. Chamberlain, Walter D. Koenig, David W. Winkler, Eric L. Walters

Biological Sciences Faculty Publications

In many cooperatively breeding taxa, nonbreeding subordinates, or helpers, use extra-territorial forays to discover dispersal opportunities. Such forays are considered energetically costly and foraying birds face aggression from conspecific members of the territories they visit. In contrast, breeders in cooperatively breeding taxa are expected to foray seldomly. We used novel tracking technologies to follow 62 acorn woodpeckers (Melanerpes formicivorus), a cooperatively breeding bird, to study extra-territorial foray behavior. Both helpers and breeders engaged in extra-territorial forays routinely and often several times per day. Helpers forayed earlier in the day and invested more time when foraying to high-quality territories. …

Do Avian Blood Parasites Influence Hypoxia Physiology In A High Elevation Environment?, Farah Ishtiaq, Sahas Barve

Biological Sciences Faculty Publications

BACKGROUND: Montane birds which engage in elevational movements have evolved to cope with fluctuations in environmental hypoxia, through changes in physiological parameters associated with blood oxygen-carrying capacity such as haemoglobin concentration (Hb) and haematocrit (Hct). In particular, elevational migrants which winter at low elevations, encounter varying intensities of avian haemosporidian parasites as they traverse heterogeneous environments. Whilst high intensity parasite infections lead to anaemia, one can expect that the ability to cope with haemosporidian infections should be a key trait for elevational migrants that must be balanced against reducing the oxygen-carrying capacity of blood in response to high elevation. In …

Predation On Artificial Turkey Nests At Radford Army Ammunition Plant In Western Virginia, Shane Brandes, Karen E. Powers, Len L. Diioia Jr.

Virginia Journal of Science

Because ground-nesting wild turkeys (Meleagris gallopavo) may sustain high incidences of nest predation in western Virginia, determining their predators is essential to understanding risk and managing the birds. Our study investigated potential predators of wild turkey nests at the Radford Army Ammunition Plant, New River Unit (RFAAP; Pulaski Co., in western Virginia). Here, we established 8 artificial nests during the breeding season for wild turkey (March-April, 2017), and documented predators via game cameras. Thirty-one species of mammals and birds visited the nests over the 31-day study. Nest predation was verified 56 times across 6 species, including coyotes ( …

Testing Alternative Hypotheses For The Cause Of Population Declines: The Case Of The Red-Headed Woodpecker, Walter D. Koenig, Eric L. Walters, Paul G. Rodewald

Biological Sciences Faculty Publications

The Red-headed Woodpecker (Melanerpes erythrocephalus) has experienced strong population declines during the past 3 decades. Using North American Breeding Bird Survey (BBS) and Audubon Christmas Bird Count (CBC) data, we investigated 4 hypotheses that may explain this decline, including: (1) interspecific competition with native Red-bellied Woodpeckers (Melanerpes carolinus) and nonnative European Starlings (Sturnus vulgaris); (2) predation by Cooper's Hawks (Accipiter cooperii) and Sharp-shinned Hawks (Accipiter striatus); (3) climate change; and (4) changes in forested area within their range. In analyses of both the breeding and overwintering periods, our results indicated …

Breeding Birds Of Virginia, Bryan D. Watts

Virginia Journal of Science

Virginia supports a diverse community of breeding birds that has been the focus of investigation for more than 400 years. The avifauna reflects the latitudinal position of the state and the fact that the border extends from the Atlantic Ocean to the Appalachian Mountains. A total of 224 species have been recorded breeding in Virginia, 214 of which are extant. Twenty species have colonized the state since 1900 including 14 since 1950. Of all extant species, 102 (48%) are considered common at least somewhere in the state and 64 (30%) are rare to very rare. Diversity varies by physiographic region …

Temporal Variability And Cooperative Breeding: Testing The Bet-Hedging Hypothesis In The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters

Biological Sciences Faculty Publications

Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenonmay be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) inpopulations living inhighly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker (Melanerpes formicivorus). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance …

The Effects Of Urbanization On Tick Parasitism Rates In Birds Of Southeastern Virginia, Erin Leigh Heller

Biological Sciences Theses & Dissertations

The coastal region of southeastern Virginia is one of the largest urban areas along one of North America’s migratory flyways. Because hundreds of avian species use this flyway, understanding factors affecting birds and their health is of paramount concern. Within this region, 14 species of ticks have been documented, all of which may serve as vectors of mammal (including human) pathogens. By sampling birds at sites of varying levels of urbanization within the coastal southeastern urban matrix, I studied the relationship between ticks and their avian hosts, and how this relationship varies seasonally. Mistnets were set-up at five permanent sites …

A Comparison Of Techniques Measuring Stress In Birds, Deborah A. O'Dell, Michael A. Carlo, Abigail Kimmitt, Ellen Bikowski, Katherine R. Morris, Andrew Dolby

Virginia Journal of Science

Free-living birds are subjected to both external and internal stresses which can affect their health, activity, and reproductive success. To study stress in free living birds, they must be captured in nets and handled by the researcher to take blood samples for commonly used measures of stress, an activity which itself can induce stress and confound results. This study compares the effects of handling time on three different measures of stress: levels of the stress hormone corticosterone (CORT), levels of Heat Shock Protein 60 (HSP 60) and the ratio of heterophils to lymphocytes (H/L ratio) in tufted titmouse (Baeolophus bicolor …

Cooperative Breeding And Long-Distance Dispersal: A Test Using Vagrant Records, Caroline L. Rusk, Eric L. Walters, Walter D. Koenig

Biological Sciences Faculty Publications

Cooperative breeding is generally associated with increased philopatry and sedentariness, presumably because short-distance dispersal facilitates the maintenance of kin groups. There are, however, few data on long-distance dispersal in cooperative breeders-the variable likely to be important for genetic diversification and speciation. We tested the hypothesis that cooperative breeders are less likely to engage in long-distance dispersal events by comparing records of vagrants outside their normal geographic range for matched pairs (cooperatively vs. non-cooperatively breeding) of North American species of birds. Results failed to support the hypothesis of reduced long-distance dispersal among cooperative breeders. Thus, our results counter the conclusion that …

Brooding, Provisioning, And Compensatory Care In The Cooperatively Breeding Acorn Woodpecker, Walter D. Koenig, Eric L. Walters

Biological Sciences Faculty Publications

We analyzed reproductive investment in parental care (brooding and the provisioning of nestlings) in the acorn woodpecker (Melanerpes formicivorus), a cooperatively breeding species in which both polygynandry and helping-at-the-nest are common. As predicted based on the strategies pursued by birds of different sex and status, breeders generally invested more in parental care than helpers, and breeder females invested more than breeder males. Contrary to expectations, however, the degree to which individuals reduced their effort with increasing group size (i.e., patterns of load lightening or compensatory care) did not match overall investment. Instead, as group size increased, there was …

Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold

Biological Sciences Faculty Publications

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful …

Effects Of Human Disturbances On The Behavior Of Wintering Ducks, Melissa L. Pease, Robert K. Rose, Mark J. Butler

Biological Sciences Faculty Publications

Human activity causes wintering waterfowl to expend energy to avoid humans at a time in their annual cycle when energy conservation is important to survival, migration, and breeding reserves. Understanding the effects of recreational activities on waterfowl is important to managing natural resource areas where migratory birds depend on wetland habitat for resting and feeding. We investigated responses of 7 species of dabbling ducks to 5 different experimental human activities, (a pedestrian, a bicyclist, a truck traveling at 2 different speeds, and an electric passenger tram). Responses of ducks depended on type of disturbance, species, and distance from disturbances. Most …

Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis

Biological Sciences Theses & Dissertations

Active anting behavior occurs when songbirds apply ants to their feathers. During anting displays, a bird draws its wings forward in front of the head and swings its tail around to the far right or left. Both wing and tail feathers are then rubbed with ants held in the bird's beak. The potential associations among ants, feather ectoparasites and birds make anting behavior an important community-level interaction. Although this behavior is cosmopolitan in distribution and occurs in a wide variety of passerine birds, it remains poorly understood. This dissertation tested hypotheses about anting behavior through controlled experiments with captive songbirds …

Effects Of Human Disturbances On The Behavior Of Dabbling Ducks, Melissa Lynn Pease

Biological Sciences Theses & Dissertations

Disturbance of wintering and migrating birds by human activities can cause birds to expend energy in avoidance of humans and reduces the time available for resting and feeding at a time in the annual cycle when fat deposition and energy conservation are important. Also, human disturbances can effectively cause habitat loss by displacing birds from feeding or resting habitat. Managers of natural resources are increasingly faced with decisions about the types and amounts of public use that should be allowed without lowering the value of the resource for wildlife. In order for managers to make decisions about how to minimize …

Determinants Of Variation In Avian Mobbing Behavior, Charles Ray Chandler Jr.

Biological Sciences Theses & Dissertations

Using three combinations of two experimental stimuli, I initiated mobbing behavior in various species of birds. The objectives of this research were to test the effects of stimuli on mobbing, the predictions of the hypothesis that mobbing functions to drive a predator away, and the effect of other species and individuals on the mobbing behavior of a bird. Mobbing experiments were conducted in a variety of habitats and locations from January 1983 through February 1984.

Only 6.5% of all trials with the mount-only stimulus were successful in attracting birds. Tape-only and mount-and-tape stimuli were equally effective in attracting birds, but …

Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose

Biological Sciences Faculty Publications

The Great Dismal Swamp located in the coastal plain on the Virginia- North Carolina border, has long been recognized as a vegetationally distinctive region with many unusual geological and biological features. Formerly at least twice the currently estimated size of 85,000 hectares (Carter 1979), the Great Dismal Swamp is still shrinking because of a dropping water table caused by more than 200 years of logging, ditching, and other human activities. In 1973, the Union Camp Corporation donated a 19,871-hectare tract located near Suffolk, Virginia. to The Nature Conservancy, which transferred the land to the U.S. Fish and Wildlife Service. This …

Duck Plague Virus An Investigation Of Cytopathic Effects, In-Vitro Host Range, And Inhibition By Phosphonoacetic Acid, Ronald Attanasio

Biological Sciences Theses & Dissertations

Duck plague is a hemorrhagic, necrotic disease found exclusively in the order Anseriformes, family Anatidae (ducks, geese, swans). The etiologic agent has been reported to be a herpes-like virus. The Holland strain of duck plague was found to induce cytopathic effects in cell culture (perinuclear vacuolation followed by lysis). A simple reproducible plaque assay for quantitating the virus was developed. Under conditions of the plaque assay, one-hit kinetics were observed. The host range of duck plague virus in cell culture was found to include the order Galliformes, family Phasianidae (pheasants, quails and partridges). Duck plague virus-induced cell culture cytopathic effects …