Show Migrating l g Birds According to the bureau of biological bio bo- logical survey few migrating birds fly higher than feet and only occasionally do they reach feet Most birds like to fly beneath the clouds and the majority majority majority ma ma- of the species migrate at a height below 1000 feet In bad weather they may fly much lower as evidenced by the number that strike against lighthouses and high buildings Birds have of course been seen at much higher altitudes altitudes alti alti- tudes but these records were es established established established es- es in mountainous countries where the birds fly a comparatively comparative comparative- ly short distance above the land The bureau explains that migrating migrating migrating ing birds fly at low rather than thaT high altitudes by the fact that the lessened buoyancy of air at great heights makes flying difficult |