Echolocation calls can be frequency modulated (FM, varying in pitch during the call) or constant frequency (CF). FM offers precise range discrimination to localize the prey, at the cost of reduced operational range. CF allows both the prey's velocity and its movements to be detected by means of the Doppler effect. FM may be best for close, cluttered environments, while CF may be better in open environments or for hunting while perched.
Echolocation calls can be frequency modulated (FM, varying in pitch during th.e call) or con,stant frequency (CF). FM offers precise range discriminatio!n to localize the prey, at? the cost of reduced operational range. CF allo.ws both the prey's velocity and its movements to be detected by means of the Doppler effect. FM may be best for close, cluttered environments, while CF may be better in open environments or for hunting while perched.