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

The North American Swans: Their Biology and Conservation

Among birds, swans are relatively long-lived species and are also among the most strongly monogamous, having prolonged pair and family bonds that strongly influence their reproductive and general social behavior, which, in combination with their beauty and elegance, contribute to the overall high degree of worldwide human interest in them. This volume of more than 59,000 words describes the distributions, ecology, social behavior, and breeding biologies of the four species of swans that breed or have historically bred in North America, including the native trumpeter and tundra swans, the introduced mute swan, and the marginally occurring whooper swan. Also included are 5 distribution maps, 15 drawings, 27 photographs by the author, and a reference section of nearly 1,000 literature citations.https://digitalcommons.unl.edu/zeabook/1089/thumbnail.jp

North American Fauna 63

Summary of the trumpeter swan, including geographic distribution, habitats for breeding and wintering, life cycle, nesting, food, limiting factors, longevity, population dynamics, and human management

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

WHOLE ISSUE \u3ci\u3eNebraska Bird Review\u3c/i\u3e (September 1994) 62(3)

Table of Contents Summer Field Report, June - July, 1994 ……………….. 102 Observers for Summer Field Report ……………….. 115 Why Bird Numbers Are Dwindling............................... 116 Publications About Birds in Nebraska ……………….. 118 Bluebird Guide................................................ 118 Nebraska ornithologists\u27 Union Fall Field Days, September 9-11, 1994 ……………….. 118 Table of Species Observed During NOU Fall Field Days, 1994 ……………….. 119 Notes on Bird Sightings in Nebraska ……………….. 12

VALENTINE NATIONAL WILDLIFE REFUGE 2011

INTRODUCTION Valentine National Wildlife Refuge (NWR) was established on August 4, 1935 under the Migratory Bird Conservation Act by Executive Order 7142. The purpose of the refuge as stated in the executive order is “as a refuge and breeding ground for migratory birds and other wildlife.” Acquisition funding came from Duck Stamp sales and the Emergency Conservation Fund Of 1933. The 71,772-acre Valentine NWR is located in the Sandhills of north-central Nebraska. The Sandhills contain the largest remaining stands of mid and tall grass native prairie left in North America. The refuge is a unique and ecologically important component of the National Wildlife Refuge System. The refuge has about 49,000 acres of grassy, undulating sand dunes, 13,000 acres of sub-irrigated meadows, and 10,000 acres of shallow lakes and marshes. The refuge is home to 271 species of birds, 59 species of mammals, and 22 species of reptiles and amphibians. The refuge is important to nesting and migrating waterfowl and is also one of the few places where good numbers of sharp-tailed grouse and prairie chickens can be found in the same area. Several threatened or endangered birds stop at the refuge during migration. Two listed plants and one listed insect are also found here. Most of the native flora and fauna found here historically are still present today. The refuge is part of a complex administered from Fort Niobrara NWR. Valentine NWR is in Cherry County with a sub-headquarters located on Hackberry Lake, 17 miles south of the town of Valentine on US 83 then 13 miles west on State Spur 16B. Valentine National Wildlife Refuge staff also manages the Yellowthroat Wildlife Management Area in Brown County (see J.3) and four easements (see F.13)

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

WHOLE ISSUE \u3ci\u3eNebraska Bird Review\u3c/i\u3e (March 1974) 42(1)

Table of Contents 1973 Treasurer\u27s ........................................... 2 1973 Nebraska Nesting Survey ...................................... 3 1973 Christmas Count ...................................... 10 Canyon Wren in Nebraska ......................... 16 A Nebraska Swainson\u27s Thrush Nest .................................... 17 Another Black-throated Sparrow in Nebraska ................................. 18 Notes .......................................................... 1

WHOLE ISSUE \u3ci\u3eNebraska Bird Review\u3c/i\u3e (March 1974) 42(1)

Table of Contents 1973 Treasurer\u27s ........................................... 2 1973 Nebraska Nesting Survey ...................................... 3 1973 Christmas Count ...................................... 10 Canyon Wren in Nebraska ......................... 16 A Nebraska Swainson\u27s Thrush Nest .................................... 17 Another Black-throated Sparrow in Nebraska ................................. 18 Notes .......................................................... 1