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Rod C. Drewien

Publications and source records attributed to Rod C. Drewien.

7 recordsLinked to original sources
USGS2001

Whooping cranes breeding at White Lake, Louisiana, 1939: observations by John J. Lynch, U.S. Bureau of Biological Survey

On 15 May 1939, John J. Lynch of the U.S. Bureau of Biological Survey located 13 whooping cranes (Grus americana), including 2 prefledged young, during an aerial survey near White Lake in southwestern Louisiana. His observation was the last historic record of whooping cranes breeding in the wild in the United States, and it confirmed the presence of a nonmigratory breeding population along the Gulf Coast. While reviewing old U.S. Fish and Wildlife Service files at the National Archives in 1999, we located Lynch's original 1939 field note, 2 letters, 5 photographs, and a draft manuscript describing the discovery; 4 other related letters also were found. Because of their biological and historical interest, we have reproduced the documents in this paper. A thorough assessment of the White Lake marshes as a potential site for returning nonmigratory whooping cranes to southwestern Louisiana should be conducted.

Book chapter↗
USGS2001

Models for the adaptive harvest management of Rocky Mountain sandhill cranes: problems and potential

The migratory Rocky Mountain Population (RMP) of the greater sandhill crane (Grus canadensis tabida) breeds primarily in river valleys, marshes, and meadows of western Montana and Wyoming, southeastern Idaho, northern Utah, and northwestern Colorado. The RMP winters primarily in the Middle Rio Grande Valley of New Mexico, with smaller concentrations in the southwestern parts of that state, southeastern Arizona, and the northern highlands of Mexico. The San Luis Valley of Colorado is used as a stopover in both the spring and fall migrations. The RMP has been hunted on a permit basis since 1981, and currently these cranes are harvested in Arizona, Idaho, Montana, New Mexico, Utah and Wyoming, and in Mexico. There are several sources of historic information on the dynamics of this population. Age ratios have been estimated from field observations in the San Luis Valley during fall migration since 1972. Cranes were banded, mostly on summer areas, from 1969-89, and re-sighted throughout the annual cycle. Aerial surveys and coordinated ground counts have been conducted either during spring migration in the San Luis Valley or in fall prior to migration since 1984 and 1987, respectively. A harvest survey has been conducted since 1981. Current monitoring programs include the fall assessment of age ratios, the fall pre-migration coordinated count, and the harvest survey. We discuss current attempts to use these information sources to build recruitment, survival, and harvest models for use in adaptive harvest management.

Book chapter↗
USGS1969

Ecological relationships of breeding blue-winged teal to prairie potholes

Ecology of breeding blue-winged teal (Anas discors) was studied on the Waubay Study Area in Day County, South Dakota, in 1965 and 1966. Breeding pair use of the wetland habitat and importance of Type 1 ponds in the wetland complex were evaluated. Changes in breeding pair densities and wetland habitat conditions on the study area were compared for the 16-year period, 1950-66.Blue-winged teal pair densities of 30.7 and 33.0 per square mile in 1965 and 1966, respectively, were above the 16-year average from 1950 to 1966 and near the maximum for this period. Blue-winged teal comprised 46.7 per cent of the waterfowl breeding population in 1965 and 51.7 per cent in 1966. Number of water areas per square mile through mid-spring 1965 was comparable to the average for the 16-year period, whereas during late spring 1965 and throughout the 1966 spring breeding seasons the number of water areas increased to near optimum conditions.Annual breeding-pair densities from 1950 to 1966 appeared to be largely influenced by water conditions, and pair-density fluctuations resulted from changes in number of wet ponds from late April through mid-May. Variations in water conditions after this period did not appear to have as great an effect on numbers of breeding teal.Use of wetland habitat by pairs changed throughout the spring breeding seasons. During the post-arrival period, teal congregated on larger wetlands. With onset of egg-laying, pairs dispersed into ponds throughout the wetland complex to establish breeding home ranges. Other factors that influenced changes in habitat use included: 1) pond type and size, 2) breeding cycle phenology, 3) availability of wet ponds, and 4) land use. Number of blue-winged teal pairs per unit area of water was highest in 1965 and 1966 on Type 1B ponds, followed in decreasing order by Types 3, 1A, and 4 and 5. Greater use of Type 1B ponds was probably related to larger ratio of edge or shore line to unit area of water. Interspersion of many small wetlands throughout the breeding habitat provided for maximum pair dispersal during egg-laying and early incubation stages of the reproductive cycle.

Report Series↗
USGS1967

Back-pack unit for capturing waterfowl and upland game by night-lighting

A night-lighting unit, designed as a light weight back-pack, proved successful for capturing waterfowl pairs, pheasants ( Phasianus colchicus ), and cottontail rabbits ( Sylvilagus floridanus ) during the spring and summer when most breeding populations are widely dispersed. Eighty ducks of seven species were captured in 48 hours (1.7 ducks per hour) of night-lighting in marsh habitat. Similarly, 30 pheasants were trapped in 25 hours (1.2 birds per hour) and 63 cottontail rabbits were either observed at close range (6-12 ft) or captured during night-lighting operations in upland habitat. Catch per hour of effort increased for all species as their night habitat requirements and reaction to night-lights became known. The mobile unit proved well suited for intensive use on small areas where other methods of capture were unfeasible and where representative coverage of various habitat types was desired. Besides its utility for capturing animals, the unit provided a method for studying nocturnal movements, behavior, and habitat use of marked animals.

South Dakota↗