U.S. Fish & Wildlife Service continues pintail and white-fronted goose telemetry studies in California
No abstract available at this time
California Waterfowl↗
Geology topics
M. R. Miller
Publications and source records attributed to M. R. Miller.
Workshop summary: Hunting vulnerability and mortality
Explore the source record for details and available documents.
Book chapter↗
Rice available to waterfowl after harvest in the Sacramento Valley is estimated
No abstract available at this time
Research Information Bulletin↗
Management implications of winter food habits of northern pintails in California
No abstract available at this time
Research Information Bulletin↗
Time budgets of northern pintails wintering in the Sacramento Valley, California
No abstract available.
California↗
Proper expression of metabolizable energy in avian energetics
We review metabolizable energy (ME) concepts and present evidence suggesting that the form of ME used for analyses of avian energetics can affect interpretation of results. Apparent ME (AME) is the most widely used measure of food energy available to birds. True ME(TME) differs from AME in recognizing fecal and urinary energy of nonfood origin as metabolized energy. Only AME values obtained from test birds fed at maintenance levels should be used for energy analyses. A practical assay for TME has shown that TME estimates are less sensitive than AME to variation in food intake. The TME assay may be particularly useful in studies of natural foods that are difficult to obtain in quantities large enough to supply test birds with maintenance requirements. Energy budgets calculated from existence metabolism should be expressed as kJ of AME and converted to food requirements with estimates of metabolizability given in kJ AME/g.
Condor↗
The display flight of The North American Ruddy Duck
Sexual behavior of the North American Ruddy Duck ( Oxyura jamaicensis ), as summarized by Johnsgard (1965: 323-327), includes a display variously referred to as the ringing rush (Johnsgard 1965: 325; 1967), ring rush (Johnsgard 1966), and/or display flight (Johnsgard 1966, 1967), which males perform as a short rush across the water surface, generally toward females. Differences of opinion exist concerning the description of the sound emitted during the display and the exact mechanics of sound production. Bailey (1919) described "a noise suggesting castanets" accompanying what probably was the display flight. Johnsgard described the noise as ringing (1965: 325) and rattling (1967). Buzzing has been used to characterize the sound produced during the display flight of the Australian Blue-billed Duck ( O. australis ), a display "which appears to correspond exactly" to the ring rush of O. jamaicensis (Johnsgard 1966). We prefer to describe the sound as popping. Wetmore (1920: 247), without naming the display, described "a great boiling in the water with wings and feet." Johnsgard attributed the noise to the wings alone (1965: 325) and, later "wings and/or feet striking the water" (1967), while Palmer (1975: 513) assigned the sound to the feet.
The Auk↗
Gut morphology of mallards in relation to diet quality
Digestive organ lengths, weights, and volumes in each of three groups of mallards ( Anas platyrhynchos ) were determined at the end of a 21-day period, during which one group was starter (control diet), another group was fed whole corn (low fiber content), and the third fed alfalfa pellets (high fiber content) to demonstrate the adaptive efficiency of the waterfowl diets of varying quality. Food consumption by the alfalfa-fed ducks was significantly gr 0.01) than the other two groups. All digestive organs of the alfalfa-fed ducks were significan (P < 0.01) than those of the corn- and turkey starter-fed ducks at the end of the study. It is that mallards can adapt rapidly to fibrous, relatively indigestible foods. This ability may hav value when higher quality foods are unavailable or when food habits change rapidly duritions.
Journal of Wildlife Management↗