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Albert T. Klett

Publications and source records attributed to Albert T. Klett.

8 recordsLinked to original sources
USGS1992

Waterfowl production on the Woodworth Station in south-central North Dakota, 1965-1981

During 17 years of study at the Woodworth, North Dakota study area, the percent of 548 wetland basin with water during 1-15 May ranged from 8 to 87 and averaged 56; waterfowl pair densities varied from 19 to 56/km2 and averaged 40/km2. Pond occupancy by duck pairs averaged 37% during mid-May counts and 48% for late May and early June counts. A positive linear relation occurred between the estimated number of duck pairs and the percent of basins with water during 1-15 May.There were 3,339 duck nests found in grassland habitats from 1966 through 1981. Approximately 66% (85% Mayfield) of these were depredated or abandoned. Mammals caused 88% of nest failures. Half or more of the eventually successful clutches were unhatched by 10 July in 9 of 16 years. Haying would have disturbed or destroyed an average of 43%, 33%, 22%, 15%, and 9% of the duck nests if initiated on 10 July, 15 July, 20 July, 25 July, and 1 August, respectively.The total average size of completed clutch for all species was 29% smaller at the end of the nesting season than at the beginning, underscoring the importance of protecting early clutches.Production averaged 30 broods per 100 pairs of ducks and ranged from 15 to 61 broods per 100 pairs. Brood densities ranged from 10 to 63/km2 and averaged 12/km2. Mean brood size averaged 6.4 for all species. July broods averaged 7.2 ducklings and August broods 5.7 ducklings. Duckling loss averaged 2.6 per brood and 85% (2.2 ducklings) of this loss was estimated to occur during the first 14 days after hatch.Wetlands of all sizes and classes were important at some time to one species of duck or another. With the exception of some diving ducks, all species used a complex of sizes and classes of wetlands for space, food, and shelter necessary for nesting and brooding. Pair counts during 20 May-7 June were most indicative of the breeding population. A combination of two brood counts resulted in the best estimate of annual production. An average of only 50% of the total duck broods per year was counted during the 1-15 July surveys, which approximated the average time of the Service's July aerial surveys. During this study the area produced an average of 1 duck per 4 ha of upland and had a nest density of approximately 1 nest per 14 ha. Nest success rates averaged 35.1% (16.3% Mayfield). Predation was significantly reduced by good vegetative cover at nest sites. Seeded grasslands (dense nesting cover) yielded better production than native prairie or croplands. Seeded grasslands also produced 3 times more ducklings per unit area than adjacent native prairie and more than 14 times as many as adjacent, annually tilled croplands.Ducks generally showed higher nest densities and better nesting success when using growing grain crops than when nesting in standing or mulched stubble fields. Among native mixed-grass prairie and seeded grassland, production was enhanced by leaving fields idle or by treating them with periodic burning. Duck production was generally lowered by grazing field of native prairie but duck production on grazing lands was higher than in annually tilled croplands.

Resource Publication↗
USGS1988

Duck nest success in the prairie pothole region

We estimated nest success of mallard ( Anas platyrhynchos ), gadwall ( A. strepera ), blue-winged teal ( A. discors ), northern shoveler ( A. clypeata ), and northern pintail ( A. acuta ) for 5 regions in North Dakota, South Dakota, and Minnesota, for 1-3 periods between 1966 and 1984, and for 8 habitat classes. We obtained composite estimates of nest success for regions and periods by weighting each habitat proportional to the number of nest initiations. The distribution of nest initiations was derived from estimates of breeding populations, preferences of species for nesting habitats, and availability of habitats. Nest success rates ranged from < 5 to 36% among regions, periods, and species. Rates were lowest in western Minnesota (MNW) and eastern North Dakota (NDE), intermediate in central North Dakota (NDC) and eastern South Dakota (SDE), and highest in central South Dakota (SDC). In regions with comparable data, no consistent trend in nest success was apparent from early to late periods. Gadwalls and blue-winged teal nested more successfully than mallards and pintails; the relative success of shovelers varied regionally. Ducks nesting in idle grassland were the most successful and those nesting in cropland were least successful. Mammalian predation was the major cause of nesting failure (54-85%) in all habitats, but farming operations resulted in 37 and 27% of the nesting failures in cropland and hayland, respectively. Most of the populations studied were not self-sustaining.

Minnesota, North Dakota, South Dakota↗
USGS1982

Variability in nest survival rates and implications to nesting studies

We used four reasonably large samples (83-213) of Mallard ( Anas platyrhynchos ) and Blue-winged Teal ( A. discors ) nests on an interstate highway right-of-way in southcentral North Dakota to evaluate potential biases in hatch-rate estimates. Twelve consecutive, weekly searches for nests were conducted with a cable-chain drag in 1976 and 1977. Nests were revisited at weekly intervals. Four methods were used to estimate hatch rates for the four data sets: the Traditional Method, the Mayfield Method, and two modifications of the Mayfield Method that are sometimes appropriate when daily mortality rates of nests are not constant. Hatch rates and the average age of nests at discovery declined as the interval between searches decreased, suggesting that mortality rates were not constant in our samples. An analysis of variance indicated that daily mortality rates varied with the age of nests in all four samples. Mortality was generally highest during the early laying period, moderately high during the late laying period, and lowest during incubation. We speculate that this relationship of mortality to nest age might be due to the presence of hens at nests or to differences in the vulnerability of nest sites to predation. A modification of the Mayfield Method that accounts for age-related variation in nest mortality was most appropriate for our samples. We suggest methods for conducting nesting studies and estimating nest success for species possessing similar nesting habits.

The Auk↗
USGS1973

Land use and prairie grouse population relationships in North Dakota

The relationship between prairie grouse and land use was studied during the period 1964-71. Prairie chickens ( Tympanuchus cupido ) declined from 48 males in 1964 to none in 1971. Sharp-tailed grouse ( Pedioecetes phasianellus ) declined from 166 males in 1964 to 57 in 1971. These declines were related to the decline in vigor and eventual loss of Soil Bank habitat on the study area. Two new courtship grounds, established near fields recently retired under the Cropland Adjustment Program, were used by 44 percent of the male sharp-tailed grouse population in 1971. Hay lands on the study area did not support prairie grouse. Pasture lands were of no apparent value to prairie chickens and of limited value to sharp-tailed grouse. Management for prairie grouse should be directed toward developing and maintaining vigorous grass-forb communities on retired croplands and native prairie.

North Dakota↗
USGS1971

Application of remote sensing techniques for appraising changes in wildlife habitat

An attempt was made to investigate the potential of airborne, multispectral, line scanner data acquisition and computer-implemented automatic recognition techniques for providing useful information about waterfowl breeding habitat in North Dakota. The spectral characteristics of the components of a landscape containing waterfowl habitat can be detected with airborne scanners. By analyzing these spectral characteristics it is possible to identify and map the landscape components through analog and digital processing methods. At the present stage of development multispectral remote sensing techniques are not ready for operational application to surveys of migratory bird habitat and other such resources. Further developments are needed to: (1) increase accuracy; (2) decrease retrieval and processing time; and (3) reduce costs.

North Dakota↗