TESTS OF BIRD DAMAGE CONTROL MEASURES IN SUDAN, 1975

The Red-billed Quelea (Quelga quelaa), because of its widespread destruction of grain crops throughout its range in Africa, is one of the most studied and written about granivorous bird species. Less publicized are more local bird pests in Africa which may be equally Important. The Village Weaver, (Ploceus cucullatus), for example, is a pest in many countries, while some other Ploecids with limited destructive habits create local problems. Significant crop losses also occur where there are large populations of Golden Sparrows (Passer luteus), House Sparrows (Passer domesticus), Red Bishops (Euplectes oryx), Doves (Streptopelia spp.), Glossy Starlings (Lamprotornis chalybaeus), Parakeets (Psittacula spp.), and some waterfowl (Mackworth-Praed and Grant, 1952; Pans Manual No. 3, 1974; Park, 1974). Crop losses from local bird pests were reported in early February 1975 to the Sudan Plant Protection Bird Control Unit of the Ministry of Agriculture. A mechanized farm scheme in Khartoum North had large concentrations of Red Bishops roosting in maize and feeding on an early-maturing wheat variety (Mexicana). Small flocks of Golden Sparrows and House Sparrows also were present. Bird damage was clearly visible, especially at the corners and along the edges of the ripening wheatfields. Ground spraying with Queletox (60% a.1. Fenthion) on roosts of the Golden and House Sparrows was conducted along hedge rows of acacia (Acacia mellifera) located at the north end of the farm. Although the spray killed large numbers of roosting birds, damage con- tinued as the wheat matured. Pilot field trials were thus organized to test the effectiveness of other crop protection techniques. Because birds fed throughout many blocks of wheat which matured at different periods, it was felt that several different experiments could be conducted without Interfering with each other. The control techniques Included an acoustical repellent, a chemical repellent, a chemical frightening agent, and a trap. The experiments, conducted from February 7 through February 23, 1975, were not designed as an integrated control operation.

1969 ASSESSMENT OF BLACKBIRD DEPREDATIONS ON FIELD CORN IN OHIO AND MICHIGAN

In 1966, when the annual damage survey was initiated, Dr. C. R. Weaver, Statistician at the Ohio Agriculture Research and Development Center, Wooster, Ohio, drew up a sampling plan, balancing costs against desired precision. The plan included three combinations of fields to be sampled and stations per field for high damage areas, three combinations for moderate damage areas, and two combinations for light damage areas. Alternatives for the high damage area included (1) 497 fields with two stations per field (± .48), (2) 775 fields with two stations per field (± .26), and (3) 235 fields with ten stations per field (— .68). For the moderate damage areas, the alternatives were (1) 441 fields with three stations per field (± .26), (2) 155 fields with three stations per field (± .50), and (3) 235 fields with ten stations per field (± .32). The light dam¬age area alternatives were (1) 297 fields with three stations per field (- .26), and (2) 81 fields with three stations per field (± .50). The original survey in 1966 sampled eight counties in three regions. In 1967, 14 counties in the same three regions were sampled. Two new counties were added to one region and two new regions with two counties each (treated as one region for sampling purposes) were added to the 1968 survey. The 1968 survey was of sufficient size to be representative of the corn damage picture in Ohio and Southeast Michigan. The 1969 survey was identical to the 1968 survey.