Publications

The masked bobwhite (Colinus virginianus ridgwayi) once inhabited restricted areas in southern Arizona and middle Sonora, Mexico. It probably never was a widespread and abundant bird. Ornithologists discovered this race in 1884, presumably during its final decline in Arizona due to overgrazing and a series of droughts. . It was gone from Arizona by 1900. Apparently the bird was not seriously threa

This report, the first of a series of reports on a comprehensive analysis of population data on the? millIard at? the continental level, provides background information including a review of the history of waterfowl management and a resume of previous studies of the mallard. The breeding range of the mallard was subdivided into 16 major and 44 minor reference areas. Each area is discussed in terms

No abstract available.

No abstract available.

Female kestrels acquired in Florida in winter as full-grown birds began laying eggs a month later than did those acquired as nestlings from northeastern United States. Egg laying dates of the two groups did not overlap in 1966 through 1968. The later nesting Florida-wintering females may have nested in captivity at a latitude farther south of their normal breeding range than did those from the Nor

Two of 14 male American kestrels died after 14 and 16 months on a diet containing 2.8 p.p.m., wet weight, p, p'-DDE. The brains of the two birds contained DDE residues of 213 and 301 p.p.m. compared with 14.9 p.p.m. (range, 4.47-26.6 p.p.m.) (wet weights) for 11 of the adult males which were sacrificed after 12 to 16 months on dosage. Autopsies of the two birds compared with autopsies of the sacri

Thirty-nine bald eagles found sick or dead in 13 States during 1969 and 1970 were analyzed for pesticide residues. Residues of DDE, dieldrin, polychlorinated biphenyls (PCB's), and mercury were detected in all bald eagle carcasses; DDD residues were detected in 38; DDT, heptachlor epoxide, and dichlorobenzophenone (DCBP) were detected less frequently. Six eagles contained possible lethal levels of

No abstract available.

The sediments cored on Leg 7 are predominantly deep sea biogenic oozes and chalks; only rarely were significant quantities of pelagic clays and volcanic detritus encountered. The biogenic sections include both siliceous and calcareous deposits. At three sites the drilling terminated in basalt, one of which (Site 62) is interpreted as being intrusive on the basis of intense alteration of the overly

Acute oral LD50 values were determined for 16 common pesticides on mallard ducks (Anas platyrhynchos), ring-necked pheasants (Phasianus colchicus), chukar partridges (Alectoris graeca), coturnix quail (Coturnix coturnix japonica), common pigeons (Columba livia), and house sparrows (Passer domesticus). Analyses of the data revealed that (1) the average sensitivity of any one species to the 16 pesti

More than 50 percent of the total abstracted geologic literature is in Russian, followed by English at about 30 percent, and French, German, and Japanese from about 8 to 2 percent. Communist Chinese publications ceased as a result of the Cultural Revolution and have not resumed. Less than 2 percent of American earth scientists read and use Russian literature in the original to any significant exte

Leg 8 sites are dominated by siliceous-calcareous biogenic oozes having depositional rates of 0.1 to 1.5 cm/1000 years. Conservative constituents of pore fluids showed, as have cores from other pelagic areas of the Pacific, insignificant or marginally significant changes with depth and location. However, in Sites 70 and 71, calcium, magnesium and strontium showed major shifts in concentration with