Capturing aerial insects available as food for chimney swifts in western Pennsylvania using a tethered balloon

Abstract

Abstract This study presents the relative abundance of aerial insects available for chimney swifts (Chaetura pelagica) to eat in Indiana, Pennsylvania in April, May, and June of 2006. Aerial insects were captured on acrylic “sticky traps” attached to the tether rope of a 3.048-m-diameter helium balloon at heights of 27 to 55 m above the ground. The methodology is evaluated, and we conclude that the described method can be carried out successfully and does provide useful data, but also has practical difficulties. The total sample size was 716 individual organisms (685 insects and 31 spiders) captured over 115.84 collecting hours. This study provides baseline information and recommendations for future studies within the context of conservation, especially concerning changes in relative abundance of aerial insect orders used for food by insectivores, such as chimney swifts. Historical and current aerial insect sampling methods are discussed.