Mute Swans and Their Chesapeake Bay Habitats:Proceedings of a Symposium

The symposium “Mute Swans and their Chesapeake Bay Habitats,” held on June 7, 2001, provided a forum for biologists and managers to share research findings and management ideas concerning the exotic and invasive mute swan (Cygnus olor). This species has been increasing in population size and is considered by many to be a problem in regard to natural food resources in the Bay that are used by native waterfowl during the winter months. Other persons, however, feel that resource managers are attempting to create a problem to justify more killing of waterfowl by hunters. Some persons also believe that managers should focus on the larger issues causing the decline of native food resources, such as the unabated human population increase in the Bay watershed and in the immediate coastal areas of the Bay. The symposium, sponsored by the Wildfowl Trust of North America and the U.S. Geological Survey, provided the atmosphere for presentation of mute swan data and opinions in a collegial setting where discussion was welcomed and was often informative and enthusiastic. An interesting historic review of the swan in regard to the history of mankind was presented, followed by a discussion on the positive and negative effects of invasive species. Biologists from different parts of the continent discussed the population status of the species in several states in the east and in the Great Lakes area. Data on the food habits of this species were presented in regard to submerged aquatic vegetation, and an interesting discussion on the role that the food habits of Canada geese in regard to native vegetation was presented. Findings and recommendations of the Mute Swan Task Force were presented. Finally, a representative of the Friends of Animals gave a thought-provoking presentation in defense of the mute swan. The presentations, in general, provided the necessary information and recommendations to allow managers to proceed with management of this controversial species with new and valuable perspectives

An assessment of impacts of Mute Swans (Cygnus olor) on submerged aquatic vegetation (SAV) in Chesapeake Bay, Maryland

Mute Swans (Cygnus olor) contribute to the localized decline in Submerged Aquatic Vegetation (SAV) through foraging in the Chesapeake Bay, Maryland. I assessed intensity of feeding activity of 868 Mute Swans in non-breeding flocks and breeding pairs through focal sampling during 2003 and 2004. I also assessed SAV reduction due to Mute Swan herbivory by measuring difference in percent cover, shoot density, and canopy height among 2 year controls (n = 54), 2 year exclosures (n = 54), and 1 year exclosures (n = 54) at 18 sites on the eastern shore during the same time period. Analyses of the time-activity budgets showed that feeding was the most predominant activity of Mute Swans. Mute Swans in flocks spent more time feeding than those in pairs and swans in larger flocks spent more time feeding than those in smaller flocks. Analyses also showed that Mute Swan herbivory caused reduction in percent cover, shoot density, and canopy height of SAV. At the end of the study, mean percent cover, shoot density, and canopy height in the controls were lower by 79%, 76%, and 40% respectively as compared to those in 2-year exclosures. Percent cover, shoot density, and canopy height increased by 26%, 15%, and 22% respectively between early and late seasons of SAV growth in exclosures, but decreased by 36%, 41%, and 18% in the controls. Non-breeding flocks that mainly occupied shallow water caused considerable (i.e., 75% to 100%) SAV reduction. On the contrary, breeding pairs mainly occupied moderate depth sites and caused less (i.e., 32% to 75%) SAV reduction.;I developed set of statistical models and selected the best one using Akaike\u27s Information Criterion and spatial models using Geographical Information Systems to predict the Bay-wide SAV decline under the influence of Mute Swan herbivory. The spatial models indicated that 43% of the total SAV area had beds of widgeon grass (Ruppia maritima) or eelgrass ( Zostera marina) (or both) with higher (i.e., 40-100%) cover and such area potentially faces intense grazing pressure by Mute Swans. Statistical modeling suggested that although Mute Swan herbivory is not the most important factor influencing bay-wide SAV decline, it certainly contributes to SAV in the Bay. Therefore Mute Swan impacts should be incorporated into a larger framework of SAV protection in the Chesapeake Bay.;As flocks (especially larger ones) are more detrimental to SAV as compared to paired Mute Swans, I recommend that emphasis primarily be placed on removing adult Mute Swans in flocks, and secondarily on pairs. Considering the goal of the Atlantic Flyway Council to reduce Mute Swan Population in the Atlantic Flyway from about 14,000 birds in 2002 to 3,000 birds by 2013, I suggest that population of Mute Swans in the Chesapeake Bay, Maryland should be reduced from 3,600 individuals in 2002 to 342 individuals by 2013

Invasive Birds: Global Trends and Impacts

This 381-paged book covers the biology, ecology, impact and management of 34 common alien invasive species, with reviews on the history and context of avian introductions and invasions in five major regions (Oceania, Africa, Europe (including the Middle East, Asia and South America)), as well as management challenges and the potential of citizen science for monitoring alien birds. The book pitches at the introductory level and is ideal for readers to gain a quick and comprehensive view of the current status of global avian invasions. It has brought the records and research of avian invasion one step ahead of other alien invasive animal taxa. Many chapters contain distribution maps and data tables on the diet and morphology of the species, providing a good reference for the species and its management issues. Each chapter also contains a rich list of references that could help readers dive further into the topic

Subsistence Harvest Diversity in Alaskan Food Sharing Networks

Two striking characteristics of human beings are the diversity of resources that we use to sustain our lives and the extent to which we engage in coordinated, collective efforts to obtain and consume these resources. Together, these two characteristics are the foundation of human subsistence patterns. In many remote Alaskan villages, these features manifest through social networks of food sharing in which a small number of households harvest the bulk of the resources consumed by the local community. For subsistence researchers in Alaska, the productivity of these households is understood to be crucial to the food security of populations that depend on subsistence resources of the bulk of their nutrition. While the diversity of resources that these communities use is acknowledged, it has not been analytically investigated. This thesis applies the quantitative methods of social network analysis and multivariate statistics to a dataset containing information on food sharing connections, resource harvest levels and their species composition, and household demographic characteristics in 8 Alaskan villages on the Middle Kuskokwim River. The goal of this analysis is to better understand the diversity of species that are used in these villages and to test whether a household’s position within a food sharing network is related to the diversity of their harvest

A comprehensive faunal analysis of Bushfield West (FhNa-10), Nipawin, Saskatchewan

Bushfield West (FhNa-l0) is a late precontact habitation site situated on a lower terrace of the Saskatchewan River valley near the town of Nipawin, in east central Saskatchewan. The site was discovered in 1976 by archaeologists from the Saskatchewan Research Council during an extensive environmental study of the Saskatchewan River valley between Nipawin and Thompson Island. The study was commissioned by the Saskatchewan Power Corporation in preparation for the construction of a 252 megawatt hydroelectric dam on the Saskatchewan River adjacent to the town of Nipawin. Construction of the facility did not begin until 1981 and in compliance with the Saskatchewan Heritage Property Act, Bill No. 88, the Saskatchewan Power Corporation funded the mitigation of heritage resources located in the dam construction site area, the reservoir area, and a 200 m wide buffer zone. Mapping, initial assessment, and salvage excavation of Bushfield West began in 1981 since the site was in immediate danger due to gravel quarrying activities on the northern edge of the flat by the Saskatchewan Department of Highways. The research potential provided by the extensive, largely undisturbed cultural deposit quickly became evident and the site was recommended for large scale mitigation in the summers of 1982 to 1984. Mitigation of the Bushfield West entailed the excavation of 624m2, uncovering numerous pieces of debitage, stone tools, ceramic sherds, bone tools, and over 100 kg of bone, as well as cultural features such as hearths, ash dumps, and rock pits. The artifact assemblage, particularly the ceramics, small side-notched projectile points, adze blades, barbed bone harpoons, bone whistles, shell beads and pendants, is characteristic of the Pehonan complex of the Selkirk Composite. Radiocarbon dates suggest that the occupation of the river terrace occurred at approximately A.D. 1600. The focus of this thesis is the description and analysis of the faunal material recovered from the three largest excavation blocks at Bushfield West, representing 529.5 m2 of the site (this does not include the fine-screen microfauna). Both are requirements for the interpretation of subsistence strategies and resource exploitation procedures carried out by the people who occupied Bushfield West. Altogether 108,135 animal bones were examined and eventually separated into unidentifiable bone fragments (93,545 pieces weighing 42.5 kg) and identifiable specimens (14,590 bones weighing 128.0 kg). A wide variety of mammal, bird, and fish resources are represented in the identifiable faunal material: bison, moose, elk, bear, canids, lynx, marten, badger, striped skunk, snowshoe hare, white-tailed jackrabbit, beaver, muskrat, red squirrel, swans, geese, teal, mallard, grouse, crane, sturgeon, northern pike, suckers, silver redhorse, shorthead redhorse, and walleye. Several factors suggest that Bushfield West was occupied in the spring of the year: most of the bird species represented at the site are spring migrants to the Nipawin region; the presence of medullary bone in some of the grouse elements; the recovery of eggshell fragments; the majority of fish species represented at the site are spring spawners; the presence of foetal and/or newborn ungulate specimens and juvenile beaver elements; and the eruption schedules and wear patterns of the bison mandibles. These are all strong indicators that the site was occupied in April, May and possibly as late as early June. The gender profile of the bison represented at the site is established using Walde's step-wise discriminant function analysis for long bone portions and Morlan's bimodiality measurements of carpals and tarsals. Economic utilization indices are used to interpret bison processing decisions. Cut marks, bone fragmentation, articulation units, and burning and calcining of large ungulate, medium-sized mammal, small-sized mammal and bird bones are described in order to identify butchering and dismemberment patterns. The results of this detailed examination of the faunal material contributes valuable information concerning the day to day activities of the occupants of Bushfield West

English medieval bone flutes c.450 to c.1550 AD

This thesis focuses on the bone flutes of medieval Britain c.450 - 1550 AD, and seeks to establish and assess their physical nature, archaeological context and cultural setting. In its broadest sense the project aims to provide the first detailed analysis of flutes, expanding a previously limited body of data and addressing the social context of the flute in medieval society. The evidence is mainly derived from the archaeological record, with 118 flutes found to date, both complete and fragmentary. Many flutes take pride of place in museum displays, and as artefacts they capture the imagination of visitors. There is, however, little or no evidence of their existence in the written or pictorial record, thus necessitating an archaeological approach. This aspect contrasts with the better known lyres, such as that found at Sutton Hoo, which are much depicted in iconography, yet there are relatively few archaeological examples. Given the wealth of potential information that a detailed study of the flutes can yield, an assessment and appraisal is clearly called for. This thesis aims to achieve just that, by a comparative approach evaluating the objects from a range of perspectives. The flutes are presented in the form of a gazetteer in Part 2, that standardizes the information for each flute and which makes the available data suitable for comparative analysis. The gazetteer provides an invaluable tool for cross-referencing information. Included as an appendix to this gazetteer are the 'non-flutes', artefacts erroneously published previously as flutes

Biology and Control of Invasive Fishes

This book is a collection of 12 peer-reviewed articles on freshwater invasive fish and is the first on this topic. It focuses on real-world lessons learned from managing common carp, bigheaded carp, sea lamprey, northern pike, and lake trout in different parts of the world. Articles also discuss damage caused by invasive fish, environmental DNA as means to measure spawning carp, and CO2 as a fish deterrent. Detailed critical evaluations of the possibility of using koi herpes virus to control common carp, market-driven fishing (invasivorism), as well as changes in lock and dam operating protocols to control bigheaded carps are also presented. Several important commonalities are noted between successful management efforts, including the simultaneous use of multiple integrated strategies, a focus on suppressing reproduction, and a deep local knowledge in an introductory article that provides context for the discipline