S3-1.4 Friday, Jan. 4 Exploring Bird, Bat and Insect Behavior Using a Vertical Profiler Radar KELLY, T. A.; Detect, Inc BashBam@aol.com
For many years researchers have attempted to quantify airborne movements of birds and bats using Doppler and X-band (marine) radar, and have often sought to eliminate insects from radar data because they create confounding “noise.” If the distribution of insectivorous bats is correlated with aerial insect distributions, then simultaneous radar detection and identification of both bats and insects would greatly improve our understanding of how insects influence the foraging and migratory behavior of bats. Tracking radar has been used to determine wing-beat frequencies of single birds and insects in flight, based on the modulation of radar reflectivity. Similarly, vertical profiler radar can detect wing beat frequencies of multiple airborne targets (birds, bats, and insects) as they pass through the fixed radar beam. Using a vertical profiler radar and modern pattern-matching algorithms, multiple airborne targets can be detected based on unique wing-beat characteristics of different airborne fauna. We are using a vertical profiler radar to evaluate relationships between the altitudinal distribution of insects and the altitude of bats while they are foraging and during migration. Because it is unlikely that all insect species provide equally optimal opportunities for bats while foraging and during migration, we are assessing a subset of insect species/groups to determine if the altitudinal distribution of bats is correlated with this subset of insects. If there is a correlation of altitudinal distributions of bats and insects, then we can use the dataset from insects to evaluate how vertical weather conditions may influence the vertical distribution of foraging behavior and migration of bats. Preliminary data will be presented that shows the vertical distribution of insects and bats in the aerosphere to illustrate how a vertical profiler radar can contribute toward understanding temporal and spatial patterns of both bat and insect activity aloft.