スミソニアン国立動物園さんのインスタグラム写真 - (スミソニアン国立動物園Instagram)「Night flight! Tracking data reveal when and why songbirds begin their massive migrations — during the darkest stages of twilight and, just like mini-meteorologists, songbirds track atmospheric pressure to ensure safe and efficient flights. Two studies published today in Movement Ecology reveal new information about when migratory songbirds begin their long-distance journeys. *** 📸 Smithsonian Intern Patty Rodriques helps position a radio tag on the back of a male Kirtland’s Warbler. 📸 A 0.35-gram coded radio tag was used to track Kirtland’s Warblers and other species in this study. 📸 Nathan Cooper, Smithsonian research ecologist and first author of the two studies, holds a radio-tagged Kirtland’s Warbler just before releasing it in The Bahamas. 📸 Cooper releases a radio-tagged Kirtland’s Warbler in The Bahamas. 📸 A male Kirtland’s Warbler perches on a young jack pine tree in Michigan.」5月2日 1時50分