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Alive & KickingSpring, Patience and Two Strong Aerialists |
Hummingbird flight is miraculous. I once saw a male display his flying skills to impress his intended. He flew vertical to about 100 feet, then dived full speed toward the ground, pulling out just above ground level and zooming skyward again at about 45 degrees.
Looking about, I spotted the female, perched and watching his display, which was repeated several times. I could not determine her verdict.
Only hummingbirds rapidly stroke a figure-eight pattern with their wings. This enables them to hover, stationary in the air. They fly at about 30-35 mph with 50 strokes of their wings per second. Daily consuming their weight in nectar, these tiny birds have the fastest metabolism of all animals, posting a heartbeat of around 525 beats per second. Their protein requirements are met by consuming small insects, which they catch in flight—perhaps the first “fast food”!
Certainly, they must be strong flyers to migrate the thousands of miles between the northern latitudes to Central and South America for their winter vacations.
Spring is brightly upon us. “My” hummingbirds have returned, males to spar for air space and females to go domestic on their garden-pea-size eggs. Their nest contains an inner cavity measuring just one-half inch deep by three-quarters of an inch in diameter, decorated with a frill of lichens around the outside. It is often bound together by spider webs. The hatchlings vacate the nest in about 21 days.
In spring, the swallows return in great numbers, weaving a tapestry through the air in celebration of coming home. They snatch insects on the wing with agility, eff ortlessly avoiding midair collisions. Swallows are among some of the most natural aerialists, making it all look so effortless.
Pictured in Greg Granger’s fine photograph is a Tree Swallow, whose upper side is greenish blue, fading to almost black at the tail. The dark coloration blends with earth tones when seen from above; from below, they are white against the sky and clouds, aff ording protection from aerial predators.
They are called Tree Swallows because they prefer nesting in holes in trees, but have adapted nicely to nesting in Purple Martin apartments or simply in bird houses when old trees with holes are scarce.
These birds return earlier in the spring, depending on weather conditions. They capture early insects or, if insects are not available, survive on waxy berries.
Tree Swallows prefer wet marshes, lakes, open areas where insects are plentiful and do very well in our area. Their summer range includes the northern four-fi ft hs of the U.S., Canada and Alaska.
The birds line their nesting space with dry grass and provide a central depression lined with feathers for their four to six white eggs. Once their clutch is complete, the female begins to incubate the eggs. The sizes of the eggs are three-quarters of an inch long and about half an inch in diameter. Hatching occurs in about 14 days. The hatchlings are fed about every five minutes during daylight hours. The second clutch of eggs is laid in early August.
Is it any wonder Tree Swallows in fall are seen in great rows on electrical wires, sometimes in the hundreds? Migrating flocks are oft en in the thousands. The Swallows winter in Mexico and Central America.
Excellent pictures, Greg! You are a man with an eye for beauty, fortifi ed by enormous patience.
Guest columnist John Cooke taught high school biology for 30 years and is pleased to share his insights with our readers.