The ruby-throated one of these can migrate 500 miles while burning off only slightly more than one gram of fat
[DOC] [TLE] hummingbird migration - ruby-throated - Nectar Art Prints [PAR] Hummingbirds could not fly against winds  a headwind of only 20 miles per hour 
... A ruby-throated hummingbird that started out weighing 1/10th of one ounce ... 
600 miles and more than 20 mph will push them backward.2 They can be blown 
... that when they gain 2 grams of fat, they have enough fuel to cross 600 miles of
... [DOC] [TLE] About RTHU  Donna DeSousa [PAR] Ruby-throated Hummingbirds (Archilochus colubris) ...