Geology topics

Research about Sacramento, California

Source-linked reports with geographic coverage including Sacramento, California.

21 records · Page 2Linked to original sources

USGS1992

Case report: Epithelial intracytoplasmic herpes viral inclusions associated with an outbreak of duck virus enteritis

Several muscovy ducks from a free-roaming flock of 65 muscovy and mallard ducks died over a 3-week period. Three muscovy ducks were necropsied. Gross and microscopic changes were compatible with duck virus enteritis, and the virus was isolated. In addition to intranuclear viral inclusion bodies in several tissues, intracytoplasmic inclusion bodies were present in esophageal and cloacal epithelium, By electron microscopy, the membrane-bound intracytoplasmic inclusions were found to contain enveloped herpesvirus, and nuclei contained herpes viral nucleocapsids.

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USGS1986

Molt chronology of northern pintails in California

Intensity and chronology of molt in 10 feather groups (head, neck, breast, belly, back, rump, side, scapular, tertial, and tail) were measured using percentages of developing feathers (pinfeathers) converted to molt scores (0-100) in samples plucked monthly from northern pintails ( Anas acuta ) collected by shooting from August through March 1980-82 in the Sacramento Valley, California. Data to supplement sample size of immatures were obtained from October 1982 through January 1983. Molt scores of the prealternate molt peaked (30-40% pinfeathers) in immature and adult females and adult males in October when nearly all feather groups were molting. The prealternate molt in immature males did not peak until November. Adult males nearly completed this molt by December; no new feather growth occurred after January. Immature males were still growing new neck, side, rump, scapular, and tertial feathers in December. Molt scores of the prebasic molt among adult and immature females peaked (30-40% new growth) in February in both years. The prealternate molt of breast and belly feathers (both sexes) peaked earlier (Sep) than molt of most other feathers (Oct). Increased molt scores in peak months were a function of a disproportionate increase of molt activity within each feather group and the number of feather groups with molt. Molt scores of the prebasic molt in adult females were less during December and January of the dry (1980-81) than the wet (1981-82) winter. Restriction or delay of molt may conserve energy or other nutrients during poor habitat conditions.

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USGS1986

Northern pintail body condition during wet and dry winters in the Sacramento Valley, California

Body weights and carcass composition of male and female adult northern pintails ( Anas acuta ) were investigated in the Sacramento Valley, California, from August to March 1979-82. Pintails were lightweight, lean, and had reduced breast, leg, and heart muscles during August-September. Ducks steadily gained weight after arrival; and body, carcass (body wt minus feathers and gastrointestinal content), fat protein, and muscle weights peaked in October-November. Fat-free dry weight remained high but variable the rest of the winter, whereas body and carcass weight and fat content declined to lows in December or January, then increased again in February or March. Gizzard weights declined from early fall to March. Males were always heavier than females, but females were fatter (percentage) than males during mid-winter. Mid-winter body weight, carcass fat, and protein content were significantly (P < 0.01) lower in the dry winter of 1980-81 than in 2 wet winters (1979-80 and 1981-82). Changes in pintail body weight and composition during winter are probably adaptations to mild climate, predictable food supplies, and requirements for pair formation and molt.

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