Direct Visual and Radar Methods for the Detection, Quantification, and Prediction of Bird Migration

摘要

The use of radar to detect, quantify, and monitor the movements of birds aloft is treated in detail. Direct visual means of studying migration are also included because these techniques aid in identifying the birds responsible for the echoes displayed on the radar screens, and they are indispensible to quantifying the radar displays of migrating birds. A new image intensifier-ceilometer technique for viewing migrating birds at night is described. The technique can be automated and permits remote monitoring by means of closed circuit television. Forecasting dense migrations of birds in spring and fall has great utility to the aviation community, and this topic is covered in some detail. The combined methods of direct visual observation and radar surveillance in conjunction with knowledge of the weather conditions that are conducive to dense movements of birds offer great promise for reducing the hazards that migrating birds pose to aircraft. The methods are also essential for basic investigations of the seasonal movements of millions of birds through the atmosphere.