Publications
This list of publications includes peer-review journal articles, official USGS publications series, reports and more authored by scientists in the Ecosystems Mission Area. A database of all USGS publications, with advanced search features, can be accessed at the USGS Publications Warehouse.
Filter Total Items: 41764
Feeding ecology of pintail hens during reproduction
Food supply has been acknowledged as one of eight major external factors regulating the sexual cycles of birds (Marshall 1961). Several hypotheses have been advanced to explain the role of food supply as an ultimate factor regulating breeding (Marshall 1951; Lack 1954, 1968; Wynne-Edwards 1962; and others). Another potential influence of food is its being a proximate stimulus to breeding. When cer
Authors
G.L. Krapu
Foods of breeding pintails in North Dakota
Food habits of breeding pintails (Anas acuta) were studied relative to sex, land use, and reproductive condition during the spring and summer of 1969, 1970, and 1971 in eastern North Dakota. Hens and drakes, respectively, consumed 79.2 percent and 30.0 percent animal matter on nontilled wetlands and consumed 16.6 percent and 1.1 percent animal matter on tilled wetlands. Aquatic dipterans (primaril
Authors
G.L. Krapu
Great horned owls and duck nest baskets
Abstract has not been submitted
Authors
H. A. Doty, E. K. Fritzell
Improved nasal-saddle marker for mallards
Abstract has not been submitted
Authors
H. A. Doty, R. J. Greenwood
Homing to nest baskets by wild female mallards
A high rate of homing to nest baskets by adult female mallards (Anas platyrhynchos) was observed in prairie potholes of North Dakota. One hundred and thirteen female mallards were caught on nest baskets, banded, and marked with nasal saddles. Forty-six percent homed at least once to nest baskets in the marshes where they were previously captured. Two-thirds of the returnees were observed in the sa
Authors
H. A. Doty, F.B. Lee
Reproductive aspects, growth, and development of Greenland mallards
No abstract available.
Authors
R. J. Greenwood
Ice on waterfowl markers
Wild and captive giant Canada geese (Branta canadensis maxima) and captive mallards (Anas platyrhynchos) accumulated ice on neck collars and/or nasal saddles during winter storm periods in 1971 and 1972. Weather conditions associated with icing were documented, and characteristics of icing are discussed. Severe marker icing occurred during subfreezing weather when the windchill reached approximate
Authors
R. J. Greenwood, W.C. Bair
A biological survey of Kraft Slough
Abstract has not been submitted
Authors
G.L. Krapu, H. F. Duebbert
Nesting cover: a critical need for prairie ducks
Abstract has not been submitted
Authors
H. F. Duebbert
Prolonged incubation behavior by a marbled godwit
On 9 May 1972 I flushed a Marbled Godwit (Limosa fedoa) from a nest containing four eggs in a large field of mulched wheat stubble in northwestern Stutsman County, North Dakota. I revisited the nest on 31 May and on 7, 9, 12, 15, 16, 20, and 21 June, and found an incubating adult on the nest during all visits except 21 June. Another adult was seen near the nest site only on 9 May. On 12 June the e
Authors
K.F. Higgins