Dr. Neil Gray recently dazzled members of The Parry Sound Nature Club with his up-close-and-personal photographs of the 47 species of hummingbird he recently saw in Colombia. “That number sounds impressive,” he said, “until you learn that Colombia is actually home to 192 species of this tiny bird.”
The world’s 340 species of hummingbirds live only in the Americas, from Alaska to Argentina. They range in size from the 2-1/4 inch Bee Hummingbird to the 8-inch Giant Hummingbird, found 14,000 feet above sea level in the high Andes. Their happy places—where 40% of the world’s hummingbirds live—are in the Andes, thanks to these mountains’ rich bounty of ecological niches.
Prehistoric hummingbirds that lived thousands of years ago were more like insects than like birds, in size and in their insect-only diet. But flowers and hummingbirds have co-evolved.
Today hummingbirds consume 75% nectar—to fuel their speedy metabolism—and 25% insects— to build up the fat reserves necessary for their long migrations north and south. (Our ruby-throated hummer grows to twice its size in August and September.)
The shape and aroma of today’s flowers has evolved to fit hummingbirds’ long narrow bills and attract specific hummingbird species. And hummingbirds evolved into birds that can hover over plants and fly in any direction, including upside down. The length and shape of their bills fits perfectly down into specific local flowers. They can use their top and bottom bills separately to trap or stab insects. Some sing or whistle, at frequencies inaudible to humans, to confuse and slow down insects, so hummingbirds can find them and pick them up faster.
Hummingbirds that live at high altitudes are bigger, stronger birds to navigate strong winds. They have hemoglobin more able to capture oxygen than hummingbirds at lower altitudes.
To fuel their constant motion, hummingbird hearts pump 1200 beats per minute. They ingest about five times their body weight in nectar daily; each sip of nectar takes 25 milliseconds. And then, within minutes, they convert the nectar into sugar and eliminate the excess water through their kidneys.
They do stop moving at night. Their body temperature drops from 40°C to 18°, their heart rate sinks to less than 200 beats per second, and their kidneys stop working.
Every hummingbird feeds from a variety of different flowers, to capitalize on different blooming times at different times of the year. The male may feed from different flowers than the female, to further spread out chances of survival.
Hummingbirds can’t smell. But they can see better than any other bird. They follow the same route of vividly coloured flowers every day, using a built-in GPS system that recognizes the location of every bloom.
They are particularly attracted to the colour red, which insects cannot see. This means that red birdfeeders are the best way to encourage these little birds to add your feeders to their daily routes.
Keep your feeder clean and filled with one part white sugar—never brown!—dissolved in four parts water. The iron in brown sugar is toxic to hummers in excess; they get all the iron they need from insects.
Thanks to Dr. Neil Gray, who shared his findings at the Parry Sound Nature Club’s February 15 meeting. Go to the Parry Sound Nature Club Facebook page to see his presentation and learn about the club’s next event, Meet the Mosses, on Wednesday, March 15 at 7 p.m.
コメント