PROGRESS ON MANAGING CATTAIL MARSHES WITH RODEO® HERBICIDE TO DISPERSE ROOSTING BLACKBIRDS

In August and September 1989 and 1990, we aerially sprayed 8 cattail (Typha spp.) marshes with Rodeo® herbicide to begin evaluating its use for fragmenting dense cattail stands used by roosting blackbirds (Icterinae). Treated marshes were effectively eliminated as roost sites for blackbirds. After 2 years, cattail densities in 4 marshes treated with Rodeo® at 5.8 - 7.0 L/ha were 87% lower than pretreatment densities (P = 0.0001). In 1990, we treated 4 marshes with Rodeo® at 4.7 L/ha. One year later, 6% of the cattails survived in the sprayed areas. Of 7 groups of indicator birds, only marsh wren (Cistothorus palustris) and rail (sora, Porzana Carolina and Virginia rail, Rallus limicola) populations were adversely affected by cattail fragmentation. These preliminary results led to an increased research effort to develop marsh management techniques aimed at eliminating blackbird roosts

1994 economic outlook: hopes become beliefs

Forecasting ; Economic conditions - United States

Food Preferences of Common Grackles, Red-Winged Blackbirds, and Yellow-Headed Blackbirds Presented with Cracked Corn, Sunflower Meats, and Brown Rice

Blackbirds migrating through North Dakota in late summer damage sunflower crops shortly after the yellow ray petals begin to wither and fall (Besser 1985). DeHaven (1982) reported bird damage losses of $7.4 million on 2.2 million acres in 1980. Various behavioral, chemical, and mechanical strategies have been employed over the past decade to reduce the damage. Although some of these methods have effectively dispersed or reduced blackbird populations, many have proven to be ineffective over time, economically infeasible, or culturally unacceptable (Guarino 1984)

The new Midwest in recession and recovery

Recessions ; Federal Reserve District, 7th ; Manufactures

1992 outlook: a question of confidence

Business forecasting

Ariel - Volume 2 Number 3

Editors Delvyn C. Case, Jr. Paul M. Fernhoff News Editors Richard Bonanno Daniel B. Gould Robin A. Edwards Lay-Out Editor Carol Dolinskas Sports Editor James J. Nocon Contributing Editors Michael J. Blecker Lin Sey Edwards Jack Guralnik W. Cherry Light Features Editor Steven A. Ager Donald A. Bergman Stephen P. Flynn Business Manager Nick Greg

HAS AN INTEGRATED PEST MANAGEMENT APPROACH REDUCED BLACKBIRD DAMAGE TO SUNFLOWER?

Since the mid- 1970s many new and modified damage abatement methods have been used to reduce blackbird damage to ripening sunflower in the northern Great Plains. To assess the overall impact of these techniques, we analyzed the dynamic relationship between breeding blackbird densities and sunflower damage. Breeding density estimates were made at both the regional and county levels, whereas, sunflower damage estimates were made at the county level only. Periodic regional estimates of breeding densities between 1967 and 1998 for red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and yellow-headed blackbirds (Xanthocephalus xanthocephalus) showed no differences among years. To increase our ability to detect changes in breeding density, we started intensive county-level surveys in 1996. These surveys, in four counties in North Dakota and South Dakota, showed that blackbird densities were greater in 1998 and 1999 than during the previous two years. We surveyed sunflower damage in two of these counties from 1994 to 1998 and found no difference in damage (F= 1.8%) among years. In 1997 and 1998, with the two other counties added to the survey, we found that damage was similar between years, averaging 2.2%. Dollar loss per hectare was trending lower in three of the study counties that had a historical database for comparison. This supports the idea that \u27local\u27 breeding densities are not correlated with damage levels. We will continue to use annual estimates of breeding densities and sunflower damage to assess the effects of an evolving Integrated Pest Management program

Ar+-Implanted Si-Waveguide Photodiodes for Mid-Infrared Detection

Complementary metal-oxide-semiconductor (CMOS)-compatible Ar+-implanted Si-waveguide p-i-n photodetectors operating in the mid-infrared (2.2 to 2.3 µm wavelengths) are demonstrated at room temperature. Responsivities exceeding 21 mA/W are measured at a 5 V reverse bias with an estimated internal quantum efficiency of 3.1%–3.7%. The dark current is found to vary from a few nanoamps down to less than 11 pA after post-implantation annealing at 350 °C. Linearity is demonstrated over four orders of magnitude, confirming a single-photon absorption process. The devices demonstrate a higher thermal processing budget than similar Si+-implanted devices and achieve higher responsivity after annealing up to 350 °C