Aquatic Birds In The Trophic Web Of Lakes: Proceedings Of A Symposium Held In Sackville, New Brunswick, Canada, In August 1991 (developments In Hydrobiology)

Birds are an integral part of most freshwater ecosystems (lakes, rivers, wetlands) but their role in the trophic dynamics of these water bodies has often been overlooked. As a conspicuous part of the biota of water bodies, aquatic birds are indicators of their trophic state both in terms of species composition (quality) as well as occupancy and breeding (quantity). Birds may also influence the trophic state of a water body by importing nutrients (.e.g. resident or migrating birds feeding on adjacent watersheds or the sea). Because of anthropogenic activities, predation or their mobility, birds may not utilize otherwise suitable aquatic habitat. These factors complicate the relationship between aquatic bird production and the trophic status of habitats. As a consequence, the role of aquatic birds in freshwater ecosystems has usually been ignored. This volume contains a wide range of papers selected from those presented at the symposium and reviewed. Front Matter....Pages i-viii Overwintering waterfowl on Swiss lakes: how are abundance and species richness influenced by trophic status and lake morphology?....Pages 1-14 Responses of breeding duck populations to changes in food supply....Pages 15-27 Birds in the trophic web of Lake Esrom, Denmark....Pages 29-38 The diet of Herring Gulls ( Larus argentatus ) during winter and early spring on the lower Great Lakes....Pages 39-55 Fish-eating bird abundance in oligotrophic lakes in Kejimkujik National Park, Nova Scotia, Canada....Pages 57-61 Abundance and feeding of wintering and migrating aquatic birds in two sampling areas of Lake Balaton in 1983–1985....Pages 63-69 Wading bird use of established and newly created reactor cooling reservoirs at the Savannah River Site, near Aiken, South Carolina, USA....Pages 71-82 Trophic web structure in a shallow eutrophic lake during a dominance shift from phytoplankton to submerged macrophytes....Pages 83-90 Cormorant ( Phalacrocorax carbo [L]) populations and patterns of abundance at breeding and feeding sites in Northern Ireland, with particular reference to Lough Neagh....Pages 91-100 Aquatic bird densities in two coastal lagoon systems in Chiapas State, Mexico, a preliminary assessment....Pages 101-106 Bird abundance and species richness on Florida lakes: influence of trophic status, lake morphology, and aquatic macrophytes....Pages 107-119 Nutrient additions by waterfowl to lakes and reservoirs: predicting their effects on productivity and water quality....Pages 121-132 The importance of avian-contributed nitrogen (N) and phosphorus (P) to Lake Grand-Lieu, France....Pages 133-147 Aquatic bird populations as possible indicators of seasonal nutrient flow at Ichkeul Lake, Tunisia....Pages 149-156 Feeding of ducks and their effects on water quality....Pages 157-161 Eutrophication and black swan ( Cygnus atratus Latham) populations: tests of two simple relationships....Pages 163-170 Use of boreal forested wetlands by Pacific loons ( Gavia pacifica Lawrence) and horned grebes ( Podiceps auritus L.): relations with limnological characteristics....Pages 171-183 Use of lakes by black duck broods in relation to biological, chemical, and physical features....Pages 185-199 Patterns of lake acidity and waterfowl communities....Pages 201-206 Duckling response to changes in the trophic web of acidified lakes....Pages 207-221 Biomechanics and foraging profitability: an approach to assessing trophic needs and impacts of diving ducks....Pages 223-233 Influence of macroinvertebrates and macrophytes on waterfowl utilization of wetlands in the Prairie Pothole Region of northwestern Wisconsin....Pages 235-246 Habitat distribution of the mallard in relation to vegetation structure, food, and population density....Pages 247-252 Food supply and the effects of recreational disturbance on the abundance and distribution of wintering Pochard on a gravel pit complex in southern Britain....Pages 253-261 Effects of weather and tides on feeding and flock positions of wintering redheads in the Chandeleur Sound, Louisiana....Pages 263-278 Use of saltwater and freshwater habitats by wintering redheads in southern Texas....Pages 279-287 Habitat selection and survival of Common Goldeneye ( Bucephala clangula ) broods — preliminary results....Pages 289-296 Breeding bird communities and environmental variable correlates of Scottish peatland wetlands....Pages 297-307 Waterfowl-wetland relationships in the Aspen Parkland of British Columbia: comparison of analytical methods....Pages 309-325 Assessment of Grey Heron predation on fish communities: the case of the largest European colony....Pages 327-344 Presence or absence of fish as a cue to macroinvertebrate abundance in boreal wetlands....Pages 345-351 Impact of Great Crested Grebes ( Podiceps cristatus L.) on fish ponds....Pages 353-366 Effects of Nile perch ( Lates niloticus ) introduction into Lake Victoria, East Africa, on the diet of Pied Kingfishers ( Ceryle rudis )....Pages 367-376 Possible competitive interactions between overwintering tufted duck ( Aythya fuligula (L.)) and fish populations of Lough Neagh, Northern Ireland: evidence from diet studies....Pages 377-386 Tufted Duck ( Aythya fuligula ) habitat use and brood survival increases after fish removal from gravel pit lakes....Pages 387-392 Loons in freshwater lakes....Pages 393-413 Activity budgets of a marked common loon ( Gavia immer ) nesting population....Pages 415-420 Habitat selection by loons in southcentral Alaska....Pages 421-430 Responses of breeding common loons to human activity in Upper Michigan....Pages 431-438 Susceptibility to freshwater acidification by two species of loon: Red-throated Loon ( Gavia stellata ) and Arctic Loon ( Gavia arctica ) in southwest Sweden....Pages 439-444 Potential risk to common loons ( Gavia immer ) from methylmercury exposure in acidified lakes....Pages 445-455 Responses to food web manipulation in a shallow waterfowl lake....Pages 457-466 Mute Swans in Great Britain: a review, current status and long-term trends....Pages 467-482 Nutrient additions to wetlands in the Interlake region of Manitoba, Canada: effects of periodic additions throughout the growing season....Pages 483-495 Nutrient additions to wetlands in the Interlake region of Manitoba, Canada: effects of a single pulse addition in spring....Pages 497-510 Changes in abundance of water birds species in southern Bohemia (Czech Republic) in the last 10 years....Pages 511-519 Sackville Waterfowl Park, Sackville, New Brunswick, Canada. Baseline characterization, towards long-term monitoring....Pages 521-524