What kind of artificial light does the nocturnal amphibian Hynobius tokyoensis need to be exposed to in order for it to be adversely affected?

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04761
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Kisarazu National College of Technology
• Principal Investigator: Yutani Kentaro 木更津工業高等専門学校, 環境都市工学科, 准教授 (00344953)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: トウキョウサンショウウオ / 光害 / 夜間行動

Outline of Final Research Achievements

The purpose of this study was to clarify the effects of color and illuminance of LED lighting on the nocturnal activity of a rare nocturnal species, the Tokyo salamander (Hynobius tokyoensis). We used white, blue, green, yellow, and red LEDs in the experiment, and compared the nocturnal activity of this species at 1 and 10 lux with that of when the lights were off. The results of the experiment indicated that the activity of this species was suppressed at higher illuminance, regardless of the light color. The results of this study suggest that the magnitude of the suppression of the nocturnal activity of this species at the same illuminance is white ≒ red > green ≒ blue > yellow.

Free Research Field

応用生態工学

Academic Significance and Societal Importance of the Research Achievements

本研究の結果から，黄色LEDを用いた照明は本種への影響を最小化することが可能になると考えられる．また，本種の自然生息地では，ゲンジボタルの生息も確認されているものの，黄色光であればゲンジボタルの成虫および幼虫に対して影響を小さくでき，同時に2種類の生物に対して配慮が可能である．しかし，全ての野生生物に対してLED単色光の影響が明らかとなっているわけではなく，特定の生物への影響が小さくなっても，他の生物への影響が大きくなる可能性も否定できず，注意が必要であると考える．