By National Geographic
Bird Migration
A few days ago, when I left the house I heard the sound only a hummingbird can make. They flap their wings at such a high rate, that I recognize it immediately. Scientists found that the wing flapping can be between 16 times per second for the larger hummingbirds, and more than 80 times per second for the smaller variety. Their top flying speed is between 34 and 49 mph and all that with their two inches in length and a weight of less than 0.07 oz.
When I heard the flapping sound, I turned around immediately and prepared their food. In the article on “hummingbirds” on our landing page, you find that our recipe is one cup of sugar to one cup of water. Before they leave in September we are a bit more generous with the sugar to “fatten” them up. After bringing the mixture to a boil, we let it cool down and then fill the two glass feeders we have. Within the hour, two males took their first drink. We assume that we have again at least two couples.
When I heard the flapping sound, I turned around immediately and prepared their food. In the article on “hummingbirds” on our landing page, you find that our recipe is one cup of sugar to one cup of water. Before they leave in September we are a bit more generous with the sugar to “fatten” them up. After bringing the mixture to a boil, we let it cool down and then fill the two glass feeders we have. Within the hour, two males took their first drink. We assume that we have again at least two couples.
How is it that these tiny birds, travel twice a year thousands of miles between their winter homes in the south and breeding grounds in the north. It seems nobody has come up with a commonly accepted answer.
You see immediately, how many miles birds travel to be with us during the summer:
You see immediately, how many miles birds travel to be with us during the summer:
By the Purple Martin Conservation Association
When I was talking to a friend who grew up 100 miles north from us, we both agreed that in the beginning of spring, it always is ten degrees warmer inland than on the coast. At that time of the year the ocean is cooling down the adjacent land as it does in the summertime. I was wondering whether this fact could explain, that one of our friends who lives near the eastern coast has tried to attract hummingbirds for years, but in vain. In the crucial time when our hummingbirds arrive, it is much warmer inland than on the coast.
How do birds succeed in traveling such a distance. Do they use the sun and the stars? Or do they follow rivers, mountains and other landmarks? It has been believed for some time now that otoliths (small oval calcareous bodies in the inner ear of vertebrates) and found in the lagenal otolith of fish and birds, may well play a role in migratory navigation, using the Earth’s magnetic fields. (Otoliths inside your inner ear- if disturbed, will lead to vertigo and loss of balance.)
Other studies have shown that geographic landmarks seem to aid in nocturnal bird migration as well. One study partially done in eastern NY State
(https://www.sciencedirect.com/science/article/pii/S0003347282802364),
found that migrating birds that were affected by wind drift, seemed to use the Hudson River to reorient their flight paths.
Other studies have shown that geographic landmarks seem to aid in nocturnal bird migration as well. One study partially done in eastern NY State
(https://www.sciencedirect.com/science/article/pii/S0003347282802364),
found that migrating birds that were affected by wind drift, seemed to use the Hudson River to reorient their flight paths.
By National Geographic Recent scientific findings suggest that an unusual protein in the bird’s eye may allow them to see the Earth’s magnetic lines, kind of like their own interstate highway. Studies from researchers at Lund University in Sweden and Carl von Ossietzky University Oldenburg in Germany, focused on the European robin (migratory) and the zebra finch (resident). They found that due to a cryptochrome protein (Cyr4) in the bird’s eyes, they probably have an enhanced sensitivity to blue light wavelengths and this may act as a kind of visual filter, giving the bird an orientation for the Earth’s magnetic field. In essence, it may give the bird a compass heading. Although this protein is present in most animals and the cryptochrome family is usually involved in regulating circadian rhythms, the studies found that it most likely is involved in the birds navigational behaviors.
By Borealbirds Most people, however, think that birds just act on instinct when they start their big trip. Our friend the ruby-throated hummingbird, probably was born here at our property last year, (or at least in the eastern part of the U.S.), and he aimed for our feeder in front of the bay window right away when I heard and then saw him. He knew where his food source was! He flew more than 3,000 miles from his winter quarters in Mexico! So how he did it is the question.
Thanks to technical advances in weather radars and their dense deployment throughout the U.S., researchers are now unlocking many of the mysteries of how, when and in what numbers, birds are moving around the globe on their epic annual journeys. This has been particularly fruitful for analyzing nocturnal migrations and how large geographic obstacles like the Great Lakes in the north, affect their paths. (One finding was that although flocks would attempt crossings of the widest stretches of water at night, the breaking of dawn would show a rise in altitude of the flock- dubbed the ‘dawn ascent’, and a redirection of their paths to follow the shore lines, implying landmark assisted navigation).
Thanks to technical advances in weather radars and their dense deployment throughout the U.S., researchers are now unlocking many of the mysteries of how, when and in what numbers, birds are moving around the globe on their epic annual journeys. This has been particularly fruitful for analyzing nocturnal migrations and how large geographic obstacles like the Great Lakes in the north, affect their paths. (One finding was that although flocks would attempt crossings of the widest stretches of water at night, the breaking of dawn would show a rise in altitude of the flock- dubbed the ‘dawn ascent’, and a redirection of their paths to follow the shore lines, implying landmark assisted navigation).
Blackcap warbler Peter Wohlleben writes in his book “The Secret Wisdom of Nature”, that a study was done by Kalev Sepp and his colleague Aivar Leito. They discovered over the years, that birds switched between three different routes. This rules out learning the route from older birds. Sepp concluded that birds have to get together and somehow ‘discuss’ where they have the best chance of finding good breeding sites and food.
Wohlleben also talks about the German blackcap warbler that has its winter quarters in Spain. In the 1960s, they found, however, another migration route that led to the United Kingdom. The reason is that the British are great bird lovers and feed the birds in their country so well that they no longer fly south. And the German blackcap warbler migrates to England now, which is considerably shorter than flying to Spain. They even have begun to change in appearance: their beaks are now longer and narrower and their wings have become rounder and shorter. Now it is easier to pick seeds and fat from feeders, and the wings are no longer suited for long-distance flights.
One might argue that this is an example of evolutionary natural selection at play. Or is it not, because human involvement seems to be the underlying cause? If these morphological changes lead to an identifiable new species over time, do we credit Darwin or human breeding? What do you think?
Wohlleben also talks about the German blackcap warbler that has its winter quarters in Spain. In the 1960s, they found, however, another migration route that led to the United Kingdom. The reason is that the British are great bird lovers and feed the birds in their country so well that they no longer fly south. And the German blackcap warbler migrates to England now, which is considerably shorter than flying to Spain. They even have begun to change in appearance: their beaks are now longer and narrower and their wings have become rounder and shorter. Now it is easier to pick seeds and fat from feeders, and the wings are no longer suited for long-distance flights.
One might argue that this is an example of evolutionary natural selection at play. Or is it not, because human involvement seems to be the underlying cause? If these morphological changes lead to an identifiable new species over time, do we credit Darwin or human breeding? What do you think?
This notion, that birds are somehow communicating why and how other birds should change to a migratory path that they had not themselves experienced, would scream heresy to many scientists! But there may be more substance to it than we can yet readily believe!
The concept implies a level of sophistication in conveying complex motives and behaviors to other- as yet naive individuals, that most people could not conceive birds of being capable of achieving.
Recent studies of bird behavior have shown that not only can some species of birds remember individual human faces, but also pass that knowledge of certain individual humans to avoid, to naive (Inexperienced) offspring. This would be considered a ‘culturally transmitted behavior’.
The concept implies a level of sophistication in conveying complex motives and behaviors to other- as yet naive individuals, that most people could not conceive birds of being capable of achieving.
Recent studies of bird behavior have shown that not only can some species of birds remember individual human faces, but also pass that knowledge of certain individual humans to avoid, to naive (Inexperienced) offspring. This would be considered a ‘culturally transmitted behavior’.
There is also increasing evidence that birds have unique alarm calls which indicate the different threat levels of an approaching cat, as opposed to that of a racoon. As our audio technologies and hunting trail cameras become ubiquitous, we are experiencing a tsunami of new data (sound, photos, videos, temperature and time stamped with moon phases) which were impossible to see until very recently. This is leading to conclusions that bird communications are far more complex and nuanced than we ever believed until now.
I suspect that as Artificial Intelligence (AI) is applied to these mountains of data, with the corresponding behaviors and audio frequencies directly compared, we will be be astonished at just how sophisticated animal communication really is. We are just- as yet, too ignorant to grasp its depth.
I suspect that as Artificial Intelligence (AI) is applied to these mountains of data, with the corresponding behaviors and audio frequencies directly compared, we will be be astonished at just how sophisticated animal communication really is. We are just- as yet, too ignorant to grasp its depth.
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