In­ves­ti­gated how owls hear, lo­cate their prey

Ottawa Citizen - - Navigator -

Masakazu Kon­ishi, who has died aged 87, was a sci­en­tist whose in­ves­ti­ga­tions into how birds de­velop their songs and sense of hear­ing made him pre-em­i­nent in the field of neu­roethol­ogy — the study of the re­la­tion­ship be­tween an­i­mals’ ner­vous sys­tems and their ob­serv­able be­hav­iour.

Kon­ishi was among the first to de­ploy tech­nol­ogy that could map the neu­ral path­ways in the avian brain.

In 1975 when he be­came a pro­fes­sor at the Cal­i­for­nia In­sti­tute of Tech­nol­ogy, Kon­ishi ar­rived with 21 owls and a deter­mi­na­tion to build upon the work of the U.S. bi­ol­o­gist Roger Payne, on how barn owls use their sense of hear­ing to lo­cate prey.

A sound­proof acous­tic cham­ber was built, equipped with a re­mote-con­trolled loud­speaker that moved around the owl’s head. Work­ing with Eric Knud­sen, Kon­ishi dis­cov­ered that cer­tain au­di­tory neu­rons in owls’ brains re­sponded only when a sound was com­ing from a par­tic­u­lar lo­ca­tion.

This finding al­lowed the two to plot an “au­di­tory space map” in the brain that al­lows owls to de­ter­mine an ob­ject’s lo­ca­tion with speed and pre­ci­sion, and thus to hunt even in com­plete dark­ness.

It proved to be a key step to­ward un­der­stand­ing how the brain of any an­i­mal species learns to read its en­vi­ron­ment, al­low­ing the in­stan­ta­neous recog­ni­tion of (for ex­am­ple) faces.

In 2005 Kon­ishi and Knud­sen re­ceived the Neu­ro­science Prize of the Peter Gru­ber Foun­da­tion.

Masakazu Kon­ishi was born in Ky­oto, Ja­pan on Feb. 17, 1933. He learned English through classes at the Amer­i­can Cul­tural Cen­ter in Sap­poro, and through mak­ing friends with U.S. army of­fi­cers and diplo­mats.

For his PhD he stud­ied bird­song by ma­nip­u­lat­ing record­ings of birds and play­ing them back to see how his test sub­jects re­acted. He fo­cused on how al­ter­ing au­di­tory feed­back — by deaf­en­ing birds with white noise or sur­gi­cally re­mov­ing the cochleas in their ears — af­fected their re­sponses.

His ex­per­i­ments showed that deafened song­birds pro­duce ab­nor­mal songs, and that the ef­fect is most pro­found when deaf­ness is in­duced at a young age.

He re­ceived nu­mer­ous awards, in­clud­ing the 1990 Internatio­nal Prize for Bi­ol­ogy.

Kon­ishi — who West­ern­ized his first name to Mark — be­came Caltech’s Bing pro­fes­sor of be­havioural bi­ol­ogy in 1980, hold­ing the po­si­tion un­til his re­tire­ment in 2013.

In later life he en­joyed train­ing bor­der col­lies to herd sheep.

Masakazu Kon­ishi

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