RUBY-THROATED HUMMINGBIRD 333 



another — an inch away, six feet away — pausing exactly in front of 

 each one, probing it with its beak, starting and stopping with a jerk, 

 almost, turning at any angle with a sudden twist; or it may shoot 

 off and away, bounding along at full speed. A remarkable power, 

 unbirdlike, more like an overgrown bee. 



Spring. — In spring the ruby-throated hummingbird leaves its trop- 

 ical or semitropical winter quarters and presses northward, keeping 

 pace as the season advances with the opening of its favorite flowers. 

 The bird's preference for some of these is so marked that it seems 

 oftentimes to regulate its migration so as to arrive on the very day 

 of their blossoming. For example, Austin Paul Smith (1915), writ- 

 ing of the Boston Mountains, Ark., says: "The arrival of the 'ruby- 

 throat' and the blossoming of the dwarf buckeye {Aesculus parvi- 

 flora) were found to be coincident. For it is upon the flowers of 

 this shrub that the ruby-throat finds most of its subsistence for the 

 first two weeks after arrival." 



At the start of the northward journey many of the tiny birds fly 

 over a wide stretch of the Gulf of Mexico on their way to the south- 

 ernmost States. They cross these dangerous waters with little con- 

 cern, apparently, for W. E. D. Scott (1890) speaks of seeing them 

 "at considerable distance from land" while he was fishing off the 

 Dry Tortugas. "One morning" he says, "I counted six pass by the 

 boat. * * * At such times their flight was direct and very rapid, 

 and all were going in a northerly direction. They flew about twen- 

 ty-five feet above the water and did not appear in any way fatigued, 

 nor show any desire to alight on the boat, as small birds crossing the 

 water so frequently do." 



Even in the Southern States hummingbirds run the danger of late, 

 killing frosts. "Didymus" (1891) tells thus of the calamity that 

 overcame them in Florida. "It was a warm winter and the early 

 opening of spring brought out the flowers and started myriads of 

 these little creatures on their journey toward the north. Then came 

 that blighting frost — which they could stand, but the 'death of the 

 flowers' was too much for them and they were picked up dead and 

 dying everywhere. They came in unusual numbers and seemed to be 

 nearly all males. After the frost but few were seen. * * *" 



On the other hand, Charles B. Floyd (193Y) describes an occasion 

 in which some hummingbirds withstood prolonged low temperature 

 and even snow : 



The following observations with Hummingbirds * ♦ * made in the 

 Laurentian Mountains of Canada during the last two weeks of May, 1936, are 

 of interest. * * * 



On May 20th the temperature in the early morning was 22 degrees Fahren- 

 heit above zero after a snowfall during the night of six inches. This snow did 

 not completely melt until late in the afternoon. The temperature the following 



