Multi-echo processing by a bottlenose dolphin operating in "packet" transmission mode at long range.
Bottlenose dolphins performing echolocation tasks at long ranges may utilize a transmission mode where bursts, or "packets," of echolocation clicks are emitted rather than single clicks. The clicks within each packet are separated by time intervals well below the two-way travel time, while the packets themselves are emitted at intervals greater than the two-way travel time. Packet use has been shown to increase with range; however, the exact function of packets and the advantages gained by their utilization remain unknown. In this study, the capability for dolphins to utilize multi-echo processing within packets of echoes was investigated by manipulating the number of available echoes within each packet as a dolphin performed a long-range echolocation task. The results showed an improvement in detectability with an increase in the number of echoes in each packet and suggest that packet use is an adaptation to allow multi-echo processing at long ranges without introducing range ambiguity.
U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Code 71510, 53560 Hull Street, San Diego, California 92152.
James J
JJ
Finneran
National Marine Mammal Foundation, 2240 Shelter Island Drive, No. 200, San Diego, California 92106.
Maddie
M
Schroth-Miller
National Marine Mammal Foundation, 2240 Shelter Island Drive, No. 200, San Diego, California 92106.
Nancy
N
Borror
National Marine Mammal Foundation, 2240 Shelter Island Drive, No. 200, San Diego, California 92106.
Megan
M
Tormey
G2 Software Systems, 4250 Pacific Highway, Suite 125, San Diego, California 92110.
Arial
A
Brewer
G2 Software Systems, 4250 Pacific Highway, Suite 125, San Diego, California 92110.
Amy
A
Black
G2 Software Systems, 4250 Pacific Highway, Suite 125, San Diego, California 92110.
Kimberly
K
Bakhtiari
G2 Software Systems, 4250 Pacific Highway, Suite 125, San Diego, California 92110.
Gavin
G
Goya
D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000502:physiology* / Q000523:psychology; D004455:Echolocation / Q000502:physiology*; D005260:Female; D012815:Signal Processing, Computer-Assisted; D016037:Single-Blind Method; D013016:Sound; D014828:Vocalization, Animal