Geology topics
M. R. Miller
Publications and source records attributed to M. R. Miller.
Development of Reliable population indices for Band-tailed pigeons
No abstract available at this time
Population energetics of northern pintails in the Sacramento Valley, California
No abstract available.
Analysis of Band-tailed Pigeon Population Estimates - 1998 Progress Report
No abstract available at this time
Productivity of mourning doves in California, 1992-95, compared to previous years and spring weather conditions
No abstract available at this time
Preliminary estimate of rice present in strip-harvested fields in the Sacramento Valley, California
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When is a teal not just a teal?
No abstract available at this time
Mourning dove nest success varied in the Sacramento Valley, California
No abstract available at this time
Hunting success in the Central Valley, California, during 1995-96 compared with previous years
No abstract available at this time
Valley Habitats: A technical guidance series for private land managers in California's Central Valley
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Northern Pintail ( Anas acuta )
The Northern Pintail is a medium-sized dabbling duck of slender, elegant lines and conservative plumage coloration. It is circumpolar in distribution and abundant in North America, with core nesting habitat in Alaska and the Prairie Pothole Region of southern Canada and the northern Great Plains. Breeders favor shallow wetlands interspersed throughout prairie grasslands or arctic tundra. An early fall migrant, the species arrives on wintering areas beginning in August, after wing molt, often forming large roosting and feeding flocks on open, shallow wetlands and flooded agricultural fields. The birds consume grains, marsh plant seeds, and aquatic invertebrates throughout the fall and winter. Northern Pintails are among the earliest nesting ducks in North America, beginning shortly after ice-out in many northern areas. Individuals form new pair bonds each winter but are highly promiscuous during the nesting season, with mated and unmated males often involved in vigorous, acrobatic Pursuit Flights. Annual nest success and productivity vary with water conditions, predation, and weather. Females build nests on the ground, often long distances from water. Only the female incubates; her mate leaves shortly after incubation begins. Ducklings hatch together in one day, follow the female to water after a day in the nest, and fledge by July or August. Adults and ducklings consume mainly aquatic invertebrates during the breeding season. Predators and farming operations destroy many thousands of Northern Pintail nests annually; farming has also greatly reduced the amount of quality nesting cover available. Winter habitats are threatened by water shortages, agricultural development, contamination, and urbanization. Periods of extended drought in prairie nesting regions have caused dramatic population declines, usually followed by periods of recovery. Over the long term, however, the continental population of Northern Pintails has declined significantly from 6 million birds in the early 1970s to less than 3 million in the late 1980s and early 1990s. However, new conservation measures, such as habitat restoration and enhancement of agricultural lands, as well as prudent harvest restrictions, suggest that Northern Pintails should have a secure future in North America.
Wildlife Resources of the Central Valley, California: The Northern Pintail
No abstract available.
Survival, habitat use, and movements of female northern pintails radio-marked in the Suisun Marsh, California
No abstract available at this time
Survival and other observations of adult female northern pintails molting in California
Survival rates of nine adult female Northern Pintails (Anas acuta) that became flightless after being radio-marked in the Sacramento Valley, California in August 1987-1989 were estimated. Seven of the radio-marked pintails molted in the Sacramento Valley, a nontraditional molting region, and two flew 280 km north to the Klamath Basin to molt. Molting marshes were dominated by emergent vegetation in both locations. Two ducks, while flightless in the Sacramento Valley, were killed by predators. Molting pintails remained sedentary (did not fly) for an average of 36 d, and the daily survival rate during this period was 0.9934. The resulting sedentary-period survival rate was 0.79. Primary feather 9 on two captive ducks grew an average of 4.2 mm per day. Mean body mass of molting ducks that died was lower than that for molting ducks that survived (P < 0.10). The number of pintails molting on Sacramento Valley refuges is probably <200.