The southward migration of ruby-throated hummingbirds continues to move through our area. While the bulk of these tiny avian treasures has already passed through, many will continue to make their way into and through the area in decreasing numbers from now through the end of October.
The vast majority of hummingbirds you see at your flowers and feeders are not local birds.
Adult male hummingbirds that breed in our area started leaving their territories in mid-July. The first baby hummingbirds that were born in our area started leaving their nests in early June.
If you didn't see hummingbirds at your flowers and feeders during June, it means these avian jewels do not breed in your immediate area. By mid-August, the only locally born hummers at our flowers and feeders are just a handful from late nesting attempts.
The birds you're seeing now may have already traveled from as far as Pennsylvania, New York or even Ontario, Canada, and mid-western Canada.
Most of the hummers you see at your feeders and flowers are one-day wonders. They're replaced the next day by others following the same route to customary wintering grounds in more tropical climes.
A few may sojourn for a couple of days, taking advantage of abundant resources to increase their body mass. All of these tiny birds will increase their weight significantly as they travel southward, and some will even double their mass by the time they reach the Gulf Coast.
The additional mass is accumulated in the form of fat located just below the skin. If you look closely at the birds visiting your feeders, some are noticeably plumper than others, and when perched may even appear to be "hump-backed."
For most of our tiny hummer friends, these fat deposits are ultimately fuel for an amazing nonstop flight across 550 miles of open water, the Gulf of Mexico.
Depending on the winds and weather conditions, this flight may take 16 to 24 hours, the tiny winglets moving nearly every inch of the way.
Hummingbirds do not glide well and must use powered flight to transport themselves.
For many years, scientists were perplexed by the question of how these miniature marvels could make such an epic journey, until they discovered the birds' ability to increase their mass by accumulating fat stores.
Fats have double the calories (energy) of carbohydrates or protein. Unlike humans, birds can readily convert their fat deposits to energy, and thus the mystery of the ruby-throated hummingbird's amazing long-distance flight ability was solved.
Pic worked when I clicked it.
