Posted on 05/31/2016 12:38:20 PM PDT by nickcarraway
Sometimes it’s surprising to discover how little we know about common plants or animals. Consider the ruby-throated hummingbird. If you live in the eastern half of Canada or the United States and have spotted a hummingbird hovering around a feeder in the backyard in summer, this is the bird you saw. But while scientists have documented many of the feeding and mating behaviors of the birds and that the birds migrate south to Central America and Cuba, there are still plenty of mysteries, such as whether the birds go the long way through Mexico when they migrate or whether they take a shortcut across the Gulf of Mexico.
It turns out that the tiny birds, some of which are small enough to fit in your hand, could easily take the shortcut, even though they’d get no break on the journey. Based on analyses of wing shape, body size and fat reserves, some of these tiny birds could fly more than 2,000 kilometers in the right winds. That’s more than enough to get them the 1,000 kilometers across the Gulf, researchers report March 9 in The Auk.
Theodore Zenzal Jr. and Frank Moore of the University of Southern Mississippi in Hattiesburg studied ruby-throated hummingbirds at the Bon Secour National Wildlife Refuge in Alabama, one of the birds’ stopovers on their journey south. From 2010 to 2014, they captured birds in the refuge during late summer and early fall. Birds were weighed, measured, banded and released.
Zenzal and Moore found that older birds tended to arrive at the refuge earlier and stayed for shorter times than younger birds. They also had more fat that could fuel a long voyage, and older males had the most. Based on these fuel loads, the birds could fly for another 2,260 kilometers on average without stopping for food, the team calculates.
That was just the average, though. Some very skinny birds arrived at the refuge, and had enough fat for just a short trip of less than 20 kilometers. This may explain why some hummingbirds stuck around in the refuge for a couple of weeks — they may have needed to bulk up before taking off again. Other birds had plenty of fat, though, enough to go more than 4,000 kilometers.
Hummingbirds’ small size may actually be an advantage when it comes to long-distance flight, the researchers note. These birds are really good at taking in a lot of fuel, and being small means that they can carry a larger percentage of their body weight as fat than can larger birds.
But just because the hummingbirds may be capable of taking the shortcut across the water doesn’t mean they actually do. Weather patterns aren’t favorable for such a flight until late fall, Zenzal and Moore say. So it may make more sense, especially for juveniles, to take the long way around since there are opportunities for pit stops should they be needed.
Last evening while we sat on the patio a hummer rammed into the window at full speed...knocked itself out...and landed in the sleeve of my polo shirt. His beak poked into the fabric. My wife gently lifted him out. After about 10 seconds of laying completely still in her open hand, he shuddered and quickly buzzed off.
There have been many anecdotal stories where birds not only returned to the same yard, but to the same bush or tree to nest, year after year; ...
*************************************
I’ve lived in my house for 30 years. Back yard has a raised tie wall bed across the width of the yard and it’s full of Carolina Jasmine mixed with wild grapevine that cascades down the 5 ft. wall.
For at least the past 25 years, each Spring there are two to four mating Cardinals that build their nests and raise the young ones in the thick foliage. .....I also have a pair of Doves each year that nest and raise young in my holly shrubs. ....The male Cardinals are a bright crimson color who is fiercely protective of the drab hens and the nests. They will first fly to a new spot in the yard and then call to the hens or fledglings that it’s safe to follow.
I believe those that show up each year are the ones that were hatched and raised here the previous year.
Yes. Just like humans, the generations learn from their forebears.
But to figure out whether it’s long-term memory, or the habit of simply knowing the locale, it matters whether the bird migrates. Cardinals don’t migrate; they are around all year, even if you don’t see them. But they’ve learned that your yard is a great nesting place, and are obviously returning to it for that important function - even if they are only a few blocks away during the rest of the year.
Of course, learning involves memory - but it’s more remarkable in migrating birds who come back to the same place after much travel and almost a year away. For instance, in my area, Catbirds migrate; but I’m convinced that they and their descendants have come back year after year, to nest in the same bush.
Most of what we know about bird behavior is still anecdotal, even though a lot of scientific studies have been done in the last few decades. A really great ‘encyclopedia’ of bird life and behavior is the series done by Arthur Cleveland Bent, which used to be published by Dover. I read these from the Library for years, and then was fortunate to inherit the entire series from a friend. You can still find the individual volumes on Amazon, or in used bookstores. You can buy them one-by-one, for the birds that interest you:
http://www.amazon.com/Arthur-Cleveland-Bent/e/B001H6WOLE
-JT
Quite true. Seeing a hummingbird always lifts my spirits.
Great saving catch! Haha!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.