The RoVing Naturalist
By Dennis Prichard
Almost every RV I see has a hummingbird feeder around it somewhere. These feisty creatures are a load of fun to watch, but their statistics are even more fascinating.
You know that their wings beat fast, but how fast? About 70 times each SECOND! That’s faster than our eyes can focus on. This is the only bird that can hover, go backwards, fly upside down, all in the blink of an eye (or faster!). The feathers on the wings can be turned in just the right way to make that seemingly impossible maneuver at the exact time it needs to. Many flowers on which they feed hang so as to allow only those pollinators that can reach the nectar, and the pollen, to complete the reproduction of the plant, and a hovering hummer fits the bill (pun intended).
There are 338 species in the world, all in the Western Hemisphere. Naturally, more species are found in the tropics because of the variety and abundance of nectar-producing flowers there. The United States boast only about 25 species, and most of them are in the West. If you see one east of the Mississippi River, it’s a good bet that it’s a Ruby-throated hummer. It’s the most common one there. But the desert Southwest and Rocky Mountains host a plethora of kinds, the Rufous being widespread and abundant. Canada and even Alaska hold plenty of hummers in season, and some birds over-winter on the chilly Pacific coast.
From sea level to over 17,000 feet in the South American Andes, these little guys get around. In migration they can fly nonstop over the Gulf of Mexico. This requires them to put on fat to fuel them across this expanse. They weigh twice the normal weight before starting their journey, and are emaciated when they finally land. Metabolism rates are the highest of any vertebrate. That keeps the wings flapping, and the heart rates have been measured at 80 beats per second, or about 1260 a minute! And to help with this oxygen intake, they breathe about 250 times each minute.
Special organ functions are adapted to make this all possible. Kidneys are especially modified to take in all the liquids and process them into energy. Muscles need to burn this energy faster than ours without cramping up.
So how does a hummingbird keep from starving in the middle of the night? It’s called torpor, or a deep sleep akin to hibernation. Metabolism slows to 1/15th of normal daytime activity. Breathing slows, heart rate drops too, and the body temperature plummets from 40 degrees Centigrade to 18 degrees. For a warm-blooded animal, this would be lethal. Not to the amazing hummingbird.
Their activities at the feeder seem almost violent. If they find a good food source like your feeder, they will defend it vigorously. And don’t waste time with food coloring in your nectar mix. It doesn’t help attract hummers. Just dilute one part sugar to four parts water. They will find it in no time. If you are stationary, leave the feeders up until the last hummers have migrated in the fall. They need the energy!
This is not their primary source of protein though. They eat tiny bugs such as gnats and mosquitoes, sometimes picking them out of spider’s webs for an easy meal. Fast food! They use the spider silk for their nest material too, as it stretches with the growth of the babies. Usually festooned with lichens or other local leaves, the nest is hard to see with this natural camouflage.
For the most variety and numbers of hummers, travel to the tropics where more than 180 different species can be seen in places like Colombia. With names like Booted racket-tail, Magnificent and Emerald, one can see why hummingbirds are brilliant!
Dennis Prichard is a retired park ranger. He’s worked and studied wildlife at many National Parks and Wildlife Refuges including Carlsbad Caverns, Mammoth Caves, the Everglades, Sequoyah NWR in Oklahoma, Sevilleta NWR in New Mexico, and Isle Royale National Park, to name a few. He travels in a fifth wheel with his wife and dog, a Labrador named Cricket.