hummingbirds
... that flying hummingbirds use oxygen at a rate which is relatively ten times greater than elite athletes?
... that flying <b id="mwBF4"><a href="./Hummingbird" id="mwBF8" rel="mw:WikiLink" title="Hummingbird">hummingbirds</a></b> <i id="mwBGA">(example pictured)</i> use oxygen at a rate which is relatively ten times greater than elite athletes?