Most people know that hummingbirds drink flower nectar. But studies have shown that hummingbirds also are masters of catching the tiniest insects, and that at least 50% of their diet is actually insects. Many insects are active even at extremely low temperatures. Many gardens also now have plants that bloom during fall and winter months, providing a source of nectar AND insects.
One way hummers survive extreme conditions is called torpor. Torpor is a kind of deep sleep, whereby an individual hummingbird lowers its metabolism by 95%, and thus body temperature (normally around 104°F/40°C), to just above the point of death by hypothermia!
Hummingbirds are among the smallest of all warm-blooded animals and lack the insulating downy feathers typical of many other bird species. Due to this and their small body size, hummingbirds rapidly lose body heat to their surroundings. Even sleeping hummingbirds have large energy demands that they must meet simply to survive. Going into nightly torpor conserves a lot of energy, allowing the bird to survive very cold and hot nights. Awakening from torpor takes 20 minutes or more, and happens automatically about an hour before dawn.
Folks have reported finding “dead” hummers hanging upside down, in the morning; but these usually turn out to be individuals in deep sleep (torpid), that have somehow loosened their foot grip just enough to slip on the perch, but not fall. They eventually wake up and begin the daily routines. Other species known to go into torpor include swifts and swallows.
Researchers use various kinds of traps, built like a bird cage, and usually operated by a pull-string. A feeder is hung in this cage, and when the hummingbird flies in, the string is pulled which closes the door behind the bird. A very fine mesh net, called a “mist net”, is also sometimes used. The birds do not see these, and so fly into them and become entangled in the soft folds of these nets.
Birds are fitted with a light-weight aluminum band imprinted with a unique number. Each band is 5.6 mm in length, and weighs about 0.005 grams. Thus, it takes 200 bands to weigh a gram, or, 5,500 to weigh an ounce. These bands are sent to banders in flat sheets. The bander must cut, file and polish smooth each band before placing it on a bird.
No. The bander places a partially opened hummingbird band into special banding pliers and slides it over the leg of the bird. The band is then crimped shut and checked to assure that it fits well. A properly fitted band does not harm the bird. There are records of banded individuals returning to feeders for 5 years or more.
General site with lots of good info on natural history, feeding; also hosts migration mapping page (part of Journey North)
- Hummingbird Mapping Projects
- The Hummer/Bird Study Group
Biggest promoters of hummer banding; this group "wrote the book" on ruby-throats
- Operation Rubythroat
Lots of educational material, especially for grades K-12