Chalk streams and grazing mute swans

The evidence shows that swan grazing can reduce plant abundance, prevent flowering, reduce water depth and reduce fishery value. However, these effects seem to be limited to a small number of sites on larger chalk streams. The results of attempted management have been disappointing, and we currently have no simple effective means of preventing grazing damage. However, our understanding of the effects of swans on the chalk stream ecosystem has been growing rapidly, which gives us hope for future solutions. In particular, combining strategies which improve river condition and move swans away from sensitive areas could offer a way of managing grazing effects

T-cell responses in oiled guillemots and swans in a rehabilitation setting

This article has been accepted for publication in the Archives of Environmental Contamination and Toxicology. The final version can be accessed from the link below.This article has been made available through the Brunel Open Access Publishing Fund.Aquatic birds are commonly affected by oil spills. Despite rehabilitation efforts, the majority of rehabilitated common guillemots (Uria aalge) do not survive, whereas mute swans (Cygnus olor) tend to have higher post-release survival. Polyaromatic hydrocarbons (PAHs) present in crude oil and diesel are immunotoxic in birds affecting cell-mediated responses to immunogens. Because it is a target of PAH toxicity, T-lymphocyte response to controlled mitogen administration (phytohemagglutinnin test) was investigated in a scoping study as a potentially useful minimally invasive in vivo test of cell-mediated immunity. The test was performed on 69 mute swans and 31 common guillemots stranded on the Norfolk and Lincolnshire coastline and inland waterways in England (UK)either due to injury or to contamination with crude or diesel oil. T-lymphocyte response was significantly decreased in swans with greater oil scores. T-lymphocyte responses were also decreased in guillemots, but this finding was not statistically significant

Factors Affecting the Harvest Vulnerability of Trumpeter Swans

Two species of swan are regularly found in Utah, tundra swans (Cygnus columbianus) and trumpeter swans (Cygnus buccinator). Tundra swans migrate through Utah. During the fall migration period they are hunted in the state under guidelines established by the United States Fish and Wildlife Service (USFWS). Trumpeter swans are occasional visitors to Utah during the same migration period. Because trumpeter swans are difficult to distinguish from tundra swans in flight, they 11 are at risk of being harvested during the swan hunt. In my thesis, I examine the factors that may influence trumpeter swan vulnerability to harvest. Specifically, I evaluated height and velocity of foraging flights for both species of swans and identified characteristics of Utah swan hunters. This information could assist the Utah Division of Wildlife Resources in developing an educational program to reduce trumpeter swan vulnerability. I applied flight dynamics theory to 86 trumpeter and 178 tundra swan measurements. Both speed and height of short-range foraging flights were used to predict trumpeter and tundra swan vulnerability. The theory predicted that trumpeter swans fly slower and lower than tundra swans, and thus may be more vulnerable to harvest. The predicted flight height of tundra swans was compared to observations of tundra swans made at the USFWS Bear River Migratory Bird Refuge. Average body area of the two species of swans was compared. Trumpeter swans had, on average, a 30% larger body area. Combining the lower predicted flight and larger body size, trumpeter swans may be up to 26% more vulnerable on a 3.8-km flight and 15% more vulnerable on a 10-km flight than tundra swans on the same flight path. In addition to current regulations, the Utah Division of Wildlife Resources is interested in implementing a swan hunter education course to further reduce the likelihood of a trumpeter swan being harvested during the swan hunt. I surveyed a representative sample of Utah swan hunters to determine if they would participate in the course and attitudes about current regulations, and to identify specific topics that should be emphasized in the course. My survey suggested that Utah swan hunters would be receptive to a swan hunter education course. Based on the responses, any swan hunter education course should emphasize identification of trumpeter and tundra swans, distance estimation, and regulations regarding the swan hunt

Conferences are like swans

Chris Corker was the lead on bringing the 2011 Higher Education Research Scholarship Group Conference to fruition, both in the months preceding the event and on the day. In this viewpoint, Chris shares his experiences of conference administration and delivery, and explores how conferences and swans have more in common that you would imagine

Book Review - The Black Swan (Random House, New York, 2007, 366 pages (hardback) ISBN 978-1-4000-6351-2)

‘Before the discovery of Australia’, the book commences, ‘people in the Old World were convinced that all swans were white, an unassailable belief as it seemed completely confirmed by empirical evidence’. The purpose of this book is to reinforce to those of us who are quantitative in our professions that sometimes a single point of data is all that is needed to disprove a long held theory – and remind us that a sample of any number of white swans does not prove the absence of black ones. ... James Dick

Current Status Of Trumpeter Swan Reintroduction At The Flathead Indian Reservation

The Confederated Salish and Kootenai Tribes, in partnership with other agencies and non-governmental organizations, commenced a project to reintroduce trumpeter swans (Cygnus buccinator) at the Flathead Indian Reservation in 1996. Between 2002 and 2010 191 swans were released on the Reservation. Released swans generally wintered locally in the lower Flathead River drainage and its tributaries, likely due to mild winter weather conditions, abundant open water and ample food resources. Wintering swans from the project were also observed in southwestern Montana, northeastern Colorado and eastern Idaho, but few of these known migrants survived. Collisions with overhead power lines accounted for the majority of documented mortalities. Cooperative efforts with the local electrical utility are underway to mark lines and the marking seems to have reduced the incidence of collision mortalities. The first wild-nesting trumpeter swans from the reintroduction project were observed in 2004 with continued successful nesting each subsequent year and a total production of 89 fledged cygnets. Future plans for the reintroduction project include additional releases of captivereared swans, continued monitoring of released and wild hatched swans, wetland habitat restoration projects, and marking of additional power lines

Black swan: Synthesis and Future Research Directions

This literature review attempts to synthesize existing research of black swan phenomenon. Using a systematic methodology, a total of 66 key articles are identified as relevant. A framework is developed for black swans, which studies theoretical aspects of black swans, black swans' effects and protection against black swans. The results show that there are only few black swan related studies and main focus should be creating a common theoretical ground work for black swan concept which should lead to more efficient prevention and protection studies, which is most vital study direction regarding black swans. The results also suggest that black swans work in complex and systematic manner and the effects can spread to other systems directly or indirectly. Study also highlights possible teleological aspects of black swan events. The study also notices that prior black swan related research which is not connected to current black swan research should be actively collected and added to current black swan research to eliminate potential unnecessary research. The thesis concludes by offering some theoretical and managerial implications.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Mute Swans

Mute swans (Cygnus olor) are an invasive species originally brought to the United States in the late 19th and early 20th centuries for ornamental ponds and lakes, zoos and aviculture collections. Original populations were located in northeastern states along the Hudson Valley but have since expanded to several Midwestern states and portions of the western U.S. and Canada. Mute swan damage includes competing with native waterfowl, destroying native plants, spreading disease, and colliding with aircraft. They are also considered a nuisance in some areas due to their abundant fecal droppings and aggressiveness towards people. Mute swans can impact ecosystems by foraging on native plants and competing with native species for food and habitat. Mute swans forage primarily on submerged aquatic vegetation, and each swan consumes 4 to 8 pounds of vegetation per day. While feeding, mute swans use their feet to expose plant shoots and roots for foraging, and to help dislodge food for cygnets (i.e., young swans). This damages aquatic substrates and vegetation surrounding preferred foods. Mute swans typically consume less than 50 percent of what they remove. Results from one study showed their diet overlaps considerably with many native waterfowl species that overwinter in the lower Great Lakes or temporarily use the area during migration. Mute swans are known for their highly territorial behavior during their breeding season, and may compete with native wildlife for space and associated resources. Of particular concern are potential impacts on threatened and endangered species. During the breeding season, mute swans sometimes displace other native waterfowl from preferred nesting locations, and may kill adult and juvenile ducks and geese. During one incident in Maryland, a large molting flock of mute swans caused a colony of least terns (Sterna antillarum) and black skimmers (Rynchops niger) to abandon a nesting colony by trampling nests, eggs, and chicks. The mute swans also displaced nesting common terns (Sterna hirundo). In 2011 in Michigan, a mute swan nest was found in the middle of a black tern (Chlidonias niger) colony that had previously supported approximately 54 black terns in 2009. Only a few black tern nests remained, approximately 30 to 40 feet away from the swan nest

Taming ‘Black Swans’: A Schmittian Perspective on State-led Crisis Management

Using a design-thinking approach to state-led crisis management, this thesis seeks to resolve the contemporary problem of Black Swans; that is, crises that are unprecedented, unexpected, unpredictable, and uncertain.Due to their nature and composition, Black Swans cause a significant increase in state fragility (Introduction). Despite this, Black Swans remain understudied within existing literature on crisis management (Chapter One). This thesis argues that Black Swans cause a significant increase in state fragility because the strategies governments and leaders currently use to recognise and contain them are sub-optimal (Chapter Two). A resolution is found by drawing resources from the legal-political theory that Carl Schmitt (1888-1985) developed between 1918 and 1933 (Chapter Three). In particular, Schmitt’s concepts of “the exception” and “sovereign dictatorship” are used to devise new strategies that enable governments and leaders to recognise and contain Black Swans optimally (Chapter Four & Chapter Five).This thesis articulates and defends a new way for constitutional states to manage Black Swans. It achieves this end by engaging in an innovative and revealing dialogue between crisis management studies and Schmittian studies (Conclusion). Unlike previous analyses, this thesis establishes that: (i) detailed strategies can be prescribed to manage Black Swans; and (ii) Carl Schmitt’s legal-political theory can be used to resolve problems at the forefront of contemporary crisis management