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Full-Text Articles in Physical Sciences and Mathematics
13.2.10. Decoy Traps For Ducks, James K. Ringelman
13.2.10. Decoy Traps For Ducks, James K. Ringelman
Waterfowl Management Handbook
Waterfowl managers and researchers must often capture ducks to band, mark, or measure. During fall and winter, cannon nets, walk-in bait traps, or swim-in traps with funnel entrances are commonly used to capture ducks. However, all of these use bait, usually grain, to lure birds. During the breeding and post-breeding periods, when the diet of many dabbling duck species is dominated by aquatic invertebrates, birds often respond poorly to bait traps. Many diving ducks do not respond to bait traps at any time of the year. Decoy traps are an effective alternative to bait traps in spring and early summer …
13.2.12. Artificial Nest Structures For Canada Geese, I. J. Ball
13.2.12. Artificial Nest Structures For Canada Geese, I. J. Ball
Waterfowl Management Handbook
Under natural conditions, Canada geese are protected from predatory mammals by selecting nest sites on islands, muskrat lodges, cliffs, or snags, or nests made by ospreys or other motors. The limited availability of safe natural sites seems to hold many goose populations below limits set by other habitat factors. The use of artificial structures to provide safe nest sites for Canada geese in North America began more than 50 years ago; structures are now among the most widely used, and most successful, of goose management practices.
Structures are considered any artificial device, with the exception of earthen or rock islands, …
13.3.3. Aquatic Invertebrates Important For Waterfowl Production, Jan Eldridge
13.3.3. Aquatic Invertebrates Important For Waterfowl Production, Jan Eldridge
Waterfowl Management Handbook
Aquatic invertebrates play a critical role in the diet of female ducks during the breeding season. Most waterfowl hens shift from a winter diet of seeds and plant material to a spring diet of mainly invertebrates. The purpose of this chapter is to give managers a quick reference to the important invertebrate groups that prairie-nesting ducks consume.
Waterfowl species depend differentially on the various groups of invertebrates present in prairie wetlands, but a few generalizations are possible. Snails, crustaceans, and insects are important invertebrate groups for reproducing ducks (Table). Most species of laying hens rely on calcium from snail shells …
13.4.2. Economic And Legal Incentives For Waterfowl Management On Private Lands, Richard D. Schultz
13.4.2. Economic And Legal Incentives For Waterfowl Management On Private Lands, Richard D. Schultz
Waterfowl Management Handbook
Waterfowl management on public lands in the United States began about 1870 with the establishment of Lake Merritt, a State-owned refuge near Oakland, California. In 1924 the United States established the Upper Mississippi River Wild Life and Fish Refuge, a complex of waterfowl habitats extending from Wabasha, Minnesota, to Rock Island, Illinois. Over the next 50 years, more than 80 million acres of county, State, and Federal lands were acquired across the United States to provide waterfowl production, migration, and wintering habitats. Because of these early (and continuing) efforts, a significant portion of North America’s remaining valuable wetland complexes exists …
13.3.3. Aquatic Invertebrates Important For Waterfowl Production, Jan Eldridge
13.3.3. Aquatic Invertebrates Important For Waterfowl Production, Jan Eldridge
Waterfowl Management Handbook
Aquatic invertebrates play a critical role in the diet of female ducks during the breeding season. Most waterfowl hens shift from a winter diet of seeds and plant material to a spring diet of mainly invertebrates. The purpose of this chapter is to give managers a quick reference to the important invertebrate groups that prairie-nesting ducks consume.
Waterfowl species depend differentially on the various groups of invertebrates present in prairie wetlands, but a few generalizations are possible. Snails, crustaceans, and insects are important invertebrate groups for reproducing ducks (Table). Most species of laying hens rely on calcium from snail shells …
13.4.4. Habitat Management For Molting Waterfowl, James K. Ringelman
13.4.4. Habitat Management For Molting Waterfowl, James K. Ringelman
Waterfowl Management Handbook
The ecology, behavior, and life history strategies of waterfowl are inseparably linked to that unique avian attribute, feathers. Waterfowl rely on flight capabilities to migrate, to fully exploit the resources of wetland and upland communities, and to escape life-threatening events. The insulation provided by contour and down feathers allows waterfowl to use a wide range of habitats and protects them from temperature extremes. Plumage is important not only for species recognition during courtship, but also for cryptic coloration of females during incubation. However, feathers become worn and must be periodically replaced. The process of feather renewal, or molt, is a …
13.1.2 Life History Traits And Management Of The Gadwall, James K. Ringelman
13.1.2 Life History Traits And Management Of The Gadwall, James K. Ringelman
Waterfowl Management Handbook
The gadwall is widely distributed throughout the western two-thirds of North America. Although its primary breeding habitat is in the drought-prone and degraded waterfowl habitats of the northern Great Plains, its continental population has remained relatively stable while those of most other dabbling ducks have declined. Some unique life history traits may in part be responsible for the resilience of gadwall populations. These unique attributes, which are important for gadwall management, are the subject of this leaflet. Readers interested in general references on gadwall biology and natural history are referred to Bellrose (1980) or Palmer (1976).
13.3.5. Ecology Of Northern Prairie Wetlands, Jan Eldridge
13.3.5. Ecology Of Northern Prairie Wetlands, Jan Eldridge
Waterfowl Management Handbook
Glaciated wetlands of the prairie pothole region are among the most productive of ecosystems. In terms of primary productivity (vegetation) they rank with the tropical rain forests (Fig. 1). Wetland productivity is controlled by water levels that fluctuate over time. However, primary productivity is highly variable for a variety of reasons including the variance in annual precipitation, the nature of the glacial till, the salinity of the water, the relation of the basin to the groundwater, and the temperature extremes typical of a continental climate.
My purpose is to review the basic patterns that contribute to the productivity of prairie …
13.4.3. Managing Agricultural Foods For Waterfowl, James K. Ringelman
13.4.3. Managing Agricultural Foods For Waterfowl, James K. Ringelman
Waterfowl Management Handbook
Agriculture, more than any other human activity, has had a profound influence on North American waterfowl. Most agricultural effects have been detrimental, such as the conversion of grassland nesting cover to cropland, the widespread drainage of wetlands, and the use of pesticides that may poison waterfowl or their food. However, some by-products of agriculture have been beneficial, particularly grain or other foods left as residue after harvest. Many waterfowl are opportunistic feeders, and some species such as Canada geese (Branta canadensis), snow geese (Chen caerulescens), mallard (Anas platyrhynchos), northern pintails (A. acuta), …