The desert plant Chuparosa grows in both our front and back yards, bringing in a resident population of Costa’s hummingbirds. Costa’s is the only true Sonoran Desert hummer, well adapted to the arid environment. Hummingbirds lap nectar from tubular shaped flowers using long beaks and tongues. They also eat soft bodied insects, gleaning their small prey from foliage or seizing them in midflight.
A hummingbird beats its wings 80 times per second, flying forward, backward, up, down and sideways. The active heart rate of this tiny being is 1260 beats per minute. This racing metabolism requires the bird to feed nearly constantly to survive.
The key to the gorgeous iridescent colors of a hummingbird is found in the cellular structure of the feathers. The light absorbing and pancake shaped “melanosomes” within the cells of feathers are filled with tiny air bubbles that create a multitude of surfaces. When sunlight glints off these surfaces we see the shimmering colors.
Males wear the dazzling pigments to attract females of course, and these flashy guys also put on astounding flight displays in breeding season. The Costa’s male loops 75 to 120 feet up into the sky, and rockets down at 60 mph, adding a whistling call to the descent, all to impress the watching female. After he has secured her attention and after the pair have mated, he moves on. The female builds her nest, incubates the eggs and raises the young on her own.
Costa’s hummingbirds nest early in the desert to take advantage of winter blooming plants such as the Chuparosa. In February the female begins collecting spider webs and binding together her walnut shell sized nest. She weaves small stems, leaves, bits of bark, and feathers into a cozy receptacle for her two bean sized eggs. The spider webs ensure the nest is stretchy enough to accommodate two rapidly growing nestlings.
Although the most arid adapted of all hummingbirds, the Costa’s that visit our yard drink frequently from the trickling water of our fountain.