Suppose if you are forced to leave your home place because of some reason and never come back. It happens in the case of migratory birds when they have to leave their home place to migrate to some other favourable place and for that, they have to adopt a long journey in which there is no guarantee whether they will be able to return back or not but if they do not migrate, in that case as well, their survival is not possible, thus they used to have migrated in any case. In this article, we will be talking about migratory birds and all about their migration. This article will help you to understand one of the major topics of environment and will increase your subject knowledge as well.
Avian Migration is one of the most common migrations or movement patterns that are seen in the birds that happen from North to South or East to West or vice versa. It also happens during seasonal change or movement between breeding and non-breeding locations. Migration is not easy and costs a lot. Birds have to cover long distances in order to reach their destinations and during these journeys, they need a lot of energy, food, water, sufficient rest, etc and not all the migration journeys become successful and some of the birds die as well in these journeys.
What are Migratory Birds?
Those birds who migrate from one location to another location in order to breed, feed, and raise their offspring, are known as migratory birds. They usually migrate from unfavourable locations to some favorable places which are having suitable conditions along with sufficient food and water resources and are also safe as well. The majority of the birds migrate during the breeding season and others migrate for food resources and because of change in seasons.
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Features of Migratory Birds
These birds are known to have good morphology as well as physiology because of which they can cover long distances by flying fast and observing various other things.
They have the ability to navigate things with good accuracy. They use the sun, the stars, the Earth's magnetism, etc.
They know when to migrate and when to return. For their specific reasons, they do not hesitate to migrate to far present locations.
They can fly as far as 16000 miles and some of the birds fly at a speed of 30mph to reach their destination. With this speed, they can reach in 533 hours whereas if they fly on the Basis of 8 hours per day, they can reach the final destination in 66 days.
They fly at different speeds and at different altitudes. Some fly at low altitudes where we can see them whereas some birds fly at high altitudes as well such as Songbirds who travel at 500 to 2000 feet whereas if we talk about Geese or Vultures, they used to fly at 29,000 to 37,000 feet altitudes.
Before migration, they prepare themselves for the journey by increasing their body weight or by keeping food reserves.
Different birds migrate at different timings but most of the birds prefer to fly at night because usually, the night is much safer for them due to fewer predators or having cooler air at night with which they can fly and rest easily.
They also prepare for their return as well because, after exhaustion of their whole energy in the long-distance journey, they usually feel hungry and require food and water.
Types of Migrating Birds
The types of migrating birds can be judged through the type of migration they adopt which can be cleared from the following:
Seasonal Migration: It happens with the change in seasons. Birds migrate from a location when they are not able to survive in harsh conditions.
Latitudinal or Longitudinal: This kind of migration happens between different latitudinal or longitudinal locations. Either North to South or East to West or vice - versa.
Altitudinal: It happens for those birds who give birth at high altitudes, and when they have to migrate again because of the harsh conditions over there.
Loop: Those who follow this kind of migration, those birds usually follow annual migration in a cycle again and again to enjoy the resources of two locations.
Nomadic: Understanding exact patterns and their timings are not easy, they stay in one place until sufficient resources are available otherwise they will migrate.
LeapFrog: It is a kind of skip migration in which birds migrate to long distances in order to skip a sedentary population.
Reverse: Aberration among birds is seen when they are confused and choose an unexpected path and go in the opposite direction.
Why Do Birds Migrate?
There are several reasons, a few of which are mentioned below:
Food is one of the major reasons for their migration. If they all stay at one place then food will be exhausted & scarce during the breeding time and thus breeding will be less successful. Thus, they migrate to food-abundant areas.
During the nesting season, the depletion of food will not only affect the adult birds but also attracts a lot of predators because they become an easy meal for them.
Birds usually migrate for their family or we can say for healthy breeding. They always required healthy conditions for raising their offspring. These conditions depend upon different species such as sources of food, weather, habitat, adequate shelter, breeding colonies, safety, etc.
Another reason can be a change in the climatic conditions. Any severe change in these conditions can cause their migration because it makes it difficult for them to survive in harsh conditions be it extra warm or extra cold.
They also can migrate to save themselves and their offspring from predators and diseases. They usually migrate to places that are inaccessible to predators.
How Do Birds Migrate?
They make different physical adaptations for the travel journey such as building extra fat supply to provide extra energy during the journey.
Keeping food and water reserves by increasing their body weight before the migration and this phenomenon of increasing weight is known as hyperphagia and a lot of birds experience this phenomenon.
They also shed their old feathers in order to make their flight easy so that it takes less energy to fly.
They used to change the altitudes as well. They fly at higher altitudes for a speedy and fast journey.
They change their behaviour of flying as well. Sometimes those birds who used to fly in the day, during migration fly at night.
Sometimes they also fly in a V pattern or we can say in a group by following the leader who has much experience and this pattern makes the journey much easier.
Migratory Birds With Names
Let's see some of the Examples of Migratory Birds which are mentioned below:
Siberian Cranes and Greater Flamingo are migratory birds that are usually seen in India in the winter season.
Asiatic Sparrow Hawk migrates to India and Myanmar during winters.
Swallow, which is a small bird, migrates from Southern England to Southern Africa.
Red Wing lives in Eurasia or the Himalayas but flies to Africa in Winter.
Sand Martin that live in Eurasia or North America usually migrate to southern areas which depend on their zones.
Whinchat who lives in Europe flies to Africa between October to March.
Common Rosefinch lives in Eurasia and flies to southern parts of Asia in Winters.
Names of other migrating birds are Black-headed gull, Green Sandpiper, Northern Lapwing, Eurasian Hobby, Gray Heron, etc.
Threats and Conservation
When birds migrate from one place to another there can be many threats to them. It took a lot of energy to cover these long-distance journeys. The major threats include exhaustion, starvation, injuries, threats from predators or hunters, diseases, pollution, natural calamities or disasters, etc.
For their conservation, we have CMS which means Convention on Migratory Species at the international level which is also famous as the Bonn convention which aims to protect migratory species such as territorial, avian, or marine, throughout their ranges and all the countries coordinate with each other for their conservation.
To sum up we can say that avian migration is not an easy task but also important for the birds as well. They require favourable conditions in order to survive and raise their young ones for which they adopt long journeys which are exhausting for them and in these journeys they have to cross the boundaries which can lead to more problems and threats for them and for which every country should adopt conservation measures for them. In this article we have covered everything about migratory birds, why and how do birds migrate, several features, their examples, etc. We believe that this comprehensive article will help you to understand this important topic and you will also think about the conservation of these species.