Echolocation
Echolocating animals
Wavelength depends on media
Dolphins produce broad-band clicks
Attenuation is due to spherical spreading &
attenuation depends on frequency in air
Bat echolocation
Bat diversity
Not all bats are aerial insectivores
Nose leaf and ear diversity
Ear and nose leaf focus sound
Echolocation call design
Hearing is tuned to echolocation frequency
FM calls during prey capture
CF calls during prey capture
Information decoded from echos
Echolocation strategies
FM bats shorten call duration to prevent pulse-echo overlap with target approach
Pulse duration declines with frequency for FM bats
How do bats estimate time delay?
Cross-correlation function can be used to measure echo delay time in FM bats
Autocorrelation and bandwidth
Call bandwidth and target ranging
Why produce constant frequency calls?
CF bats detect wing flutter as echo glints
CF bats exhibit doppler-shift compensation
Individual Pteronotus bats use unique CF frequencies
Combination-sensitive neurons encode range and velocity in CF bats
Call design and foraging strategy
Email: gw10@umail.umd.edu
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