Question of the week:
Q. When should I stop feeding hummingbirds in the fall? I have heard that if I feed too late in the year the hummingbirds will delay their southward migration. Is this true?
A. Judging from aviators' observations, pelicans, geese and ducks sometimes travel as high as 8,000 to 9,000 feet, several species of shorebirds reach 12,000 feet; and storks occasionally fly at 20,000 feet. Great elevated land masses, of course, often force birds passing over to fly at heights far above normal. On the Mount Everest Expedition of 1921, Dr. Wollaston recorded a lammergeier (bearded vulture) at 24,000 or 25, 000 feet, and identified curlews and godwits passing over at 20,000 feet.
Other explorers in the Himalayas have been astonished to hear the calls of large flocks of nocturnal migrants flying over the frigid temperatures at 18,000 to 20,000 feet. In the Field (December 18, 1920, p. 876) it is stated that an observer while making photographic observations of the sun at Dehra Dun in India obtained a picture of geese flying at an estimated altitude of 29,000 feet.