Bird Migration is the seasonal movement of birds, often from the north to the south, in search of resources, between breeding and wintering grounds.
It is a natural response made when there are changes in food availability, weather or habitat conditions, and so on. It is one of the most captivating features birds possess.
Migrations can be as long as North Wheateaters who go around the globe, or as short as Clark Nutcracker’s seasonal shift, where they go up and down a mountain slope.
To us human beings with all our developments and such, it might seem like a hassle and an extreme adaptation to changing conditions.
But as we will see going forward, it is a process as natural and straightforward to birds as breathing is to humans.
It is their best defense against seasonal changes in conditions, and science shows how this travel is embedded in their genes.
Today, we will take a deep and thorough look at one of the most fascinating miracles of nature.
We will look at what migration is, how it works, how the birds know the shift in seasons, and most importantly, how they navigate their way so far away from home. Let’s get started!
First Off, Why Do Birds Migrate?
Put in simple terms, birds migrate when there is a shortage of resources and they migrate to areas with higher resources or where resources are increasing.
Apart from food, resources also mean safe shelter, that is away from predators. The seasonal shifts also play a major role when they decide to make the move.
Though the temperature itself is not a strong enough force to drive away birds, scarcity of food certainly is.
Research shows that hummingbirds are able to withstand freezing temperatures well below their body temperature if they have enough food reserves to get through the harsh period.
Thus, birds that inhabit the Northern hemisphere tend to move northward still during the springtime because of the increase in the insect population.
As the days become shorter in autumn, the birds return to warmer areas where the food supply varies little with the seasons.
How Do Birds Know It’s Time For Migration?
Avian migration is a true miracle. Birds fly hundreds of thousands of kilometers in search of places where there are the best ecological and environmental factors present to live and raise their young.
As soon as conditions turn unfavorable, they make the long and arduous journey again.
So we must ask, what triggers the journey? How do they know it’s time to move again? And how do they orient themselves so wonderfully?
The main physiological trigger for migration is when the length of the day changes, which is related to hormonal changes in the birds.
During a pre-migration period, the birds may become restless and have a period of increased activity levels.
They also prepare their metabolism for the journey as the body starts increasing its depositing of fat.
These physiological changes have astonishingly been found in even caged birds, who have no environmental cues either, which is further proof of the fact that the timing and triggers are embedded in their systems through years of evolution.
Birds navigate their journey using a variety of senses. They have been observed using different methods of navigation like using the sun as a compass, detecting magnetic fields, detecting olfactory differences, and using visual hints.
Yet the endogenous programming and environmental cues are not enough to explain the strict navigation birds are capable of.
Birds are also incredibly smart creatures and have the cognitive ability to make mental maps and remember landmarks along their journey.
When observed over a period of several years, it was observed that the birds followed the same path every single year, with little to no deviation in their path.
The navigation techniques and journey pathways also differ from species to species.
Some migrating species like cranes have been observed to have preferred pathways annually.
They traverse the same path not only for familiarity’s sake but also because these paths have many stops where the birds can restock on their interior resources in between the long journey.
Some smaller birds, studies show, use different routes in spring and fall, according to the seasonal conditions and how that affects the food reserves of the regions.
What Is Bird Migration Called?
Bird Migration, also called Avian Migration is the process by which different birds make long and arduous journeys across hundreds of thousands of kilometers in search of resources, including food and safe shelter to live and raise their young ones in.
The routes followed by the birds are generally referred to as ‘flyways’
Where Do Birds Migrate To From The UK?
Most birds that migrate from the United Kingdom do so in autumn and travel the astonishing 8000 kilometers all the way to Africa!
They pass over an impressive collection of land embedded with mountains, valleys, and deserts to escape the cold and wet weather of the UK.
What Are The Reasons For Bird Migration?
The primary reason birds migrate is for resources. They move from areas with low or decreasing resources to those with high or increasing resources.
Resources here is a general term that encompasses mainly food, as well as shelter for the birds to live in and raise their children in.
The temperature is also a factor, but it is not as crucial. With an adequate amount of food, birds have been observed to withstand freezing temperatures.
Migration is an incredible process, and only gets more so every time you study more things about it.
It is one of the true wonders of the animal kingdom and we hope you learned something new about the process today!
So the next time the weather is cold and you see a hoard of birds traveling in their signature formation, know that you’re witnessing one of the fascinating miracles of nature!
Thank you for reading!
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