open access

https://hdl.handle.net/2115/78809

The effects of visual impediment on the approaching behavior of harbor porpoise, Phocoena phocoena

英語

visual guidance

2019-07-03

日本哺乳類学会（The Mammal Society of Japan.）

Mammal study

44(3)

205-213

Studies on odontocetes (e.g., porpoises) have revealed that these animals may adaptively use vision. The present study examined the contributions of vision to the approaching behavior of the harbor porpoise (Phocoena phocoena). When a porpoise approached a target, the time-to-contact perceived by the animal and its trajectory with a visual impediment condition were compared with those in the control (no impediment) condition. The results suggested that approaching behavior to a stationary target was guided by the animal's evaluation of time-to-contact (tau), maintaining the time derivative of tau ((tau) Over dot) at a constant value. A porpoise with visual deprivation exhibited grater (tau) Over dot) value and a longer evaluation time before contact than a porpoise that was not blindfolded in the task of reaching for the target. Furthermore, the porpoise with a visual impediment changed its swimming trajectory toward a target less than the control, which appeared to adaptively adjust its approaching trajectory. These findings imply that the use of vision aided echolocation and enables precise control and alteration of the trajectory during the approach. The present study has implications for adaptive use of vision during approaching behavior in the harbor porpoise.

学術雑誌論文

Version of Record

1343-4152

AA11185060