BREEDING BIOLOGY OF HOUSE MARTINS DELICHON URBICA IN RELATION TO AERIAL INSECT ABUNDANCE

Summary The breeding biology of House Martins nesting in artificial boxes was examined in relation to aerial insect abundance and weather. The insect food supply was continuously monitored with a suction‐trap at 40 ft above ground level. Aerial insect abundance started to rise from the winter level in April and reached a high stable state in June. Insects remained abundant until September; the subsequent decline continued at least until the end...