LYCOS RETRIEVER 
The Hummingbirds: Energy
built 270 days ago
As the fall weather cools, semiconscious hummingbirds may be found on branches, window sills or in garages. If they are picked up the warmth of the hand is usually enough to revive them, and they buzz off in perfect health. These birds are exhibiting a behavior akin to hibernation. On cold nights, their body temperature will drop as much as 20 degrees. This is probably an adaptation to conserve energy because of the hummingbirds' high metabolic rate.
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Most hummingbirds set up a territory and defend it against other hummingbirds. In a captive situation hummingbirds can become very territorial because they cannot disperse and go somewhere else. Birds that have been in an aviary for a period of time will hold well defined territories and at times try to increase the territory size. Since the captive birds are not expending energy migrating or towards some of the other activities wild birds would be involved in they have a lot of energy to defend territories. This can be detrimental to newly introduced birds. Hummingbirds should be allowed to set up territories in captivity but well established birds should not be allowed to increase their territories at other birds expense.
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Feeding hummingbirds is a very enjoyable way to observe the smallest of all birds. Tiny as they are, their energy requirements are huge. but to do so, they must consume roughly 50% of their body weight in nectar every day!
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To maintain their energy levels, hummingbirds eat every 15 to 20 minutes and may visit around 1,000 flowers per day. When they are unable to feed due to the weather, they go into a condition in which their metabolic rate comes down to only one-fifteenth of normal sleep.
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