Warning: Undefined array key "visitor_referer_type" in /var/www/vhosts/wordinf.com/core/app/libraries/Core.php on line 98 David Attenborough - Its heart that in flight...
Its heart that in flight contracted a thousand times a minute, slows until its beat is virtually undetectable. Its body temperature falls dramatically, and its breathing seems to cease altogether. [...] It's hibernating; but for a hummingbird, winter comes 365 times a year.