I had this question in my mind because of - well, humans, what else!
I was wondering if one could shift fromthe sweltering heat of Chennai or dangerous Delhi or crowded Mumbai to just about any other favourable climate or favourable condition.
Can they seamlessly establish a new life in a new place? What do they have to do before they migrate? When India was partitioned how did the partition affect people? Many were forced to migrate. They lost all their land. To man, land is everything, isn't it? To be thrown out of one's land.. is unfortunate. To lose it to a calamity like Uttarkhand or Tsunami is even more unfortunate. How do these people, who lose everything (imagine all your certificates and life savings down the drain) reconstruct their lives? I cannot even imagine such things. It's a huge ordeal.
It is for such fears and unfathomable reasons that I fear migrating to the US of A. I know that we can make a lot of money and travel the world and take our parents there (which both our parents love to) but there is a downside to it. I hate to be called Alien. In my country I wouldn't have to bear the Alien tag. Nobody accuses me of stealing their jobs.. I can wear our ethnic dress without being stared at. I can eat a little more organic and natural food here, which is a horrible thing in US. All vegetables are devoid of taste. Their desserts are too sugary. The country too big for my comfort. Overall I slip into deep depression there, despite it having so many comforts. So, H1B has bothered me. Occasionally I succumb to temptations and invitations from friends but that dies off in days. Chaotic as it is, with the spiralling price of commodities, I feel content in my own land.
Coming back to the idea of migration, that reminded me of the great animal migration. I had heard of animal migration in South Africa and of some birds which migrate thousands of miles in search of better weather.
So, I went ahead and fed myself some info by reading:
http://www.livescience.com/10235-animals-migrate.html
So why do they do it? Migration is driven by a simple fact: Resources on Earth fluctuate. Warm summer months may be followed by inhospitable cold. Plants – or other meals – may be abundant, but only for a short time. The best place to give birth or hatch young may not be a good place to find food.
And why not find a shorter, simpler journey or stop altogether? "The simple answer is that the benefits of long-distance migration outweigh its cost and the benefits of shorter distances,".
While migrations can be complex and varied, the motivations behind them are simple. Food, breeding and climate are recurring themes.
Natural selection shapes these journeys, and it has programmed this traveling nature into many animals, putting a destination in their genes. But the innate sense that points these migratory animals in the right direction has remained something of a mystery.
For instance, direction and distance must be encoded in a songbird's genes, because young birds make their first flight alone, according to Susanne Åkesson of Lund University in Sweden. The birds also have a genetically based internal clock that allows them to synchronize their behavior – whether preparing for migration or becoming sexually active – with the seasons.
The genetic structure of these abilities is not well understood, Åkesson said.
Scientists do know, however, that migrants can use the sun, the stars, reflected light, the Earth's magnetic field and their sense of smell to find their way.
Regardless of its genetic components, migration is not mandatory. In the early 1900s, the pronghorn antelope population, for example, stopped migrating as their numbers dwindled. After roughly 50 years, the pronghorn population in Wyoming returned a certain level and the migration resumed, according to Jon Beckmann, an associate conservation ecologist with the Wildlife Conservation Society.
Closely related populations of a European bird, the black cap warbler, display a full range of migratory behavior, from traveling long distances to staying put, Åkesson said.
"If you don't have any need to change environments, you might not just activate this program encoding the activity to move from a certain area," she said. "But maybe the capability is present in most birds."
Migrants have evolved to respond to cues, such as changes in day length, that tell them it's time to move. Waiting too long brings a number of risks, including losing the opportunity to stock up on food before departure or losing the competitive edge that comes with early arrival at your next habitat.
In addition to being pre-emptive, the travelers are focused. They don't meander, and they aren't distracted by food or mates along the way. The migrant generation of monarch butterflies is unable to reproduce until after it has reached its southern destination. And migrating aphids are initially drawn to the blue light of the sky, then, as their journey progresses, to the yellow light reflected by their preferred food, young leaves.
Single-mindedness makes sense, Dingle said. "If you get distracted, you are not going to get where you need to go."
How do they do it?
In addition to guiding migrants to a tried-and-true destination, natural selection has taught many migrants how to take advantage of winds or currents that will aid or even carry them to their destinations.
"You evolve to take advantage of abilities that already exist," Dingle said. "Birds already can fly, to take the simplest case, so instead of just restricting flights to short distances, you evolve a mechanism to take flights to long distances."
Research on migrating birds showed that, the more rounded their wings were and the more weight they carried per wing area, the greater their heart rates and energy expenditures were. The birds could make their flights more energy-efficient by avoiding high winds and turbulence.
Meanwhile, migratory butterflies appear to have developed larger and more elongated wings.
Migrating animals also have to prepare. The bar-tailed godwits stuff themselves, more than doubling their weight before they begin their autumn flight, according to Anders Hedenström from Lund University. They also increase the mass of their flight muscle slightly, but over the course of the flight, it is partially consumed, and they lose weight elsewhere by shrinking their intestines and liver. During a long, snackless flight, these organs make for unnecessary payload, Hedenström said. Similar physiological changes have been observed in other migrating birds.
Their journeys aren't easy; migrants fast, swim upstream, fly nonstop, and face hungry predators and barriers built by humans. The journeys may be fatal to some; however, mortality data is difficult to obtain, according to Dingle.
"My own suspicion is that it's a lot less than people think. They just seem able to do it well," he said.
I was wondering if one could shift fromthe sweltering heat of Chennai or dangerous Delhi or crowded Mumbai to just about any other favourable climate or favourable condition.
Can they seamlessly establish a new life in a new place? What do they have to do before they migrate? When India was partitioned how did the partition affect people? Many were forced to migrate. They lost all their land. To man, land is everything, isn't it? To be thrown out of one's land.. is unfortunate. To lose it to a calamity like Uttarkhand or Tsunami is even more unfortunate. How do these people, who lose everything (imagine all your certificates and life savings down the drain) reconstruct their lives? I cannot even imagine such things. It's a huge ordeal.
It is for such fears and unfathomable reasons that I fear migrating to the US of A. I know that we can make a lot of money and travel the world and take our parents there (which both our parents love to) but there is a downside to it. I hate to be called Alien. In my country I wouldn't have to bear the Alien tag. Nobody accuses me of stealing their jobs.. I can wear our ethnic dress without being stared at. I can eat a little more organic and natural food here, which is a horrible thing in US. All vegetables are devoid of taste. Their desserts are too sugary. The country too big for my comfort. Overall I slip into deep depression there, despite it having so many comforts. So, H1B has bothered me. Occasionally I succumb to temptations and invitations from friends but that dies off in days. Chaotic as it is, with the spiralling price of commodities, I feel content in my own land.
Coming back to the idea of migration, that reminded me of the great animal migration. I had heard of animal migration in South Africa and of some birds which migrate thousands of miles in search of better weather.
So, I went ahead and fed myself some info by reading:
http://www.livescience.com/10235-animals-migrate.html
Birds do it. Fish do it. Mammals, insects and reptiles do it. Migrate, that is.
Migration is nearly universal within the animal kingdom; in fact,
even sponge and jellyfish larvae make use of that defining animal trait,
mobility, to adapt to imperfect habitats. Animals across the globe fly,
swim, walk or drift in their effort to find food, a more hospitable climate or places to breed. These primal drives lead to arduous and often treacherous treks, some spanning thousands of miles.
So why do they do it? Migration is driven by a simple fact: Resources on Earth fluctuate. Warm summer months may be followed by inhospitable cold. Plants – or other meals – may be abundant, but only for a short time. The best place to give birth or hatch young may not be a good place to find food.
And why not find a shorter, simpler journey or stop altogether? "The simple answer is that the benefits of long-distance migration outweigh its cost and the benefits of shorter distances,".
While migrations can be complex and varied, the motivations behind them are simple. Food, breeding and climate are recurring themes.
Natural selection shapes these journeys, and it has programmed this traveling nature into many animals, putting a destination in their genes. But the innate sense that points these migratory animals in the right direction has remained something of a mystery.
For instance, direction and distance must be encoded in a songbird's genes, because young birds make their first flight alone, according to Susanne Åkesson of Lund University in Sweden. The birds also have a genetically based internal clock that allows them to synchronize their behavior – whether preparing for migration or becoming sexually active – with the seasons.
The genetic structure of these abilities is not well understood, Åkesson said.
Scientists do know, however, that migrants can use the sun, the stars, reflected light, the Earth's magnetic field and their sense of smell to find their way.
Regardless of its genetic components, migration is not mandatory. In the early 1900s, the pronghorn antelope population, for example, stopped migrating as their numbers dwindled. After roughly 50 years, the pronghorn population in Wyoming returned a certain level and the migration resumed, according to Jon Beckmann, an associate conservation ecologist with the Wildlife Conservation Society.
Closely related populations of a European bird, the black cap warbler, display a full range of migratory behavior, from traveling long distances to staying put, Åkesson said.
"If you don't have any need to change environments, you might not just activate this program encoding the activity to move from a certain area," she said. "But maybe the capability is present in most birds."
Migrants have evolved to respond to cues, such as changes in day length, that tell them it's time to move. Waiting too long brings a number of risks, including losing the opportunity to stock up on food before departure or losing the competitive edge that comes with early arrival at your next habitat.
In addition to being pre-emptive, the travelers are focused. They don't meander, and they aren't distracted by food or mates along the way. The migrant generation of monarch butterflies is unable to reproduce until after it has reached its southern destination. And migrating aphids are initially drawn to the blue light of the sky, then, as their journey progresses, to the yellow light reflected by their preferred food, young leaves.
Single-mindedness makes sense, Dingle said. "If you get distracted, you are not going to get where you need to go."
How do they do it?
In addition to guiding migrants to a tried-and-true destination, natural selection has taught many migrants how to take advantage of winds or currents that will aid or even carry them to their destinations.
"You evolve to take advantage of abilities that already exist," Dingle said. "Birds already can fly, to take the simplest case, so instead of just restricting flights to short distances, you evolve a mechanism to take flights to long distances."
Research on migrating birds showed that, the more rounded their wings were and the more weight they carried per wing area, the greater their heart rates and energy expenditures were. The birds could make their flights more energy-efficient by avoiding high winds and turbulence.
Meanwhile, migratory butterflies appear to have developed larger and more elongated wings.
Migrating animals also have to prepare. The bar-tailed godwits stuff themselves, more than doubling their weight before they begin their autumn flight, according to Anders Hedenström from Lund University. They also increase the mass of their flight muscle slightly, but over the course of the flight, it is partially consumed, and they lose weight elsewhere by shrinking their intestines and liver. During a long, snackless flight, these organs make for unnecessary payload, Hedenström said. Similar physiological changes have been observed in other migrating birds.
Their journeys aren't easy; migrants fast, swim upstream, fly nonstop, and face hungry predators and barriers built by humans. The journeys may be fatal to some; however, mortality data is difficult to obtain, according to Dingle.
"My own suspicion is that it's a lot less than people think. They just seem able to do it well," he said.
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