Search USGS⌕ Search

SEARCH · Search USGS

Results for “Leaflet”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
USGS1989

Lead poisoning: The invisible disease

Lead poisoning is an intoxication resulting from absorption of hazardous levels of lead into body tissues. Lead pellets from shot shells, when ingested, are the most common source of lead poisoning in migratory birds. Other far less common sources include lead fishing sinkers, mine wastes, paint pigments, bullets, and other lead objects that are swallowed.

Fish and Wildlife Leaflet↗
USGS1989

Avian botulism: geographic expansion of a historic disease

Avian botulism is a paralytic, often fatal disease of birds resulting from ingestion of toxin produced by the bacterium Clostridium botulinum. Waterfowl die-offs from the botulism are usually caused by type C toxin; sporadic die-offs among fish-eating birds, such as common loons (Gavia immer) and gulls, have been caused by type E toxin.

Fish and Wildlife Leaflet↗
USGS1992

Ecology of playa lakes

Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region. More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region. The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

Fish and Wildlife Leaflet↗
USGS1988

Nutritional values of waterfowl foods

wetland habitats throughout their annual cycles. Survival, reproduction, and growth are dependent on the availability of foods that meet nutritional requirements for recurring biological events. These requirements occur among a wide variety of environmental conditions that also influence nutritional demands. Recent work on nesting waterfowl has identified the female’s general nutrient needs for egg laying and incubation. Far less is known about nutritional requirements for molt and other portions of the life cycle, particularly those during the nonbreeding season. Although information on specific requirements for amino acids and micronutrients of wild birds is meager, the available information on waterfowl requirements can be used to develop waterfowl management strategies. For example, nutrient content of foods, nutritional requirements of waterfowl, and the cues waterfowl use in locating and selecting foods are all kinds of information that managers need to encourage use of habitats by feeding waterfowl. Waterfowl nutritional needs during the annual cycle and the nutritional values of natural foods and crops will be discussed below.

Fish and Wildlife Leaflet↗
USGS1991

Chufa biology and management

Chufa (Cyperus esculentus) is an emergent perennial sedge that is common in seasonally flooded wetlands. Although chufa is common in many States, it is most abundant in the Southeast, including the Mississippi alluvial valley (Fig. 1). Belowground biomass of chufa, especially the tubers, serves as a valuable food source for waterfowl and cranes. Chufa tubers rank tenth among the most important waterfowl foods in the United States.

Fish and Wildlife Leaflet↗
USGS1992

Management of habitat for breeding and migrating shorebirds in the Midwest

Shorebirds have always relied on the extensive network of natural wetlands from Texas to North Dakota. This network has now been fractured by wetland drainage and agriculture to the point where suitable wetlands are absent in much of the Midwest. Habitat loss and the resulting risk of population decline highlight the importance of management of shorebirds on refuges, hunting clubs, and preserves for both breeding and migrating species.

Fish and Wildlife Leaflet↗
USGS1947

Disease control in hatchery fish

A direct method for controlling diseases among hatchery fish has long been sought as an alternative to the earlier technique of hand dipping. A simple, practical, effective method of direct pond treatment not only obviates all need for handling fish weakened by disease, but it would materially reduce the time and effort required by hatcherymen in keeping diseases under control. Furthermore, a direct pond treatment could be used for routine prophylaxis to eradicate diseases during their incipient stages--long before their presence becomes apparent. Several methods for applying direct pond treatments in coldwater-fish culture have been proposed. Kingsbury and Embody (1932) developed a technique for applying disinfectants directly to the inflowing water of a pond. Later, Fish (1939) advocated a method involving the recirculation of a disinfecting solution through a fish pond. For various reasons, neither of these methods proved to be an effective answer to the problem of controlling hatchery diseases and neither became widely adopted. The method described herein has been extensively tested, both in the laboratory and at the producing hatchery, over a period of several years. Once familiarity with the details of application have been mastered, th8 reduction in effort required to treat fish is amazing. For example, two men have treated 20 large ponds containing several million fish, in one morning with no significant increase in mortality of the fish, whereas a crew of eight men required a full day to treat a single similar pond by hand dipping the fish with a subsequent loss approximating 50 percent of the stock.

Fishery Leaflet↗
USGS1963

Sacramento River chinook disease

Epizootics among chinook salmon fingerlings at the Coleman National Fish Hatchery have occurred periodically since 1941. A virus or virus-like filterable agent has been demonstrated to be the causative agent of this disease.

Leaflet↗