For anyone familiar with wildlife documentaries like the ones from the National Geographic, it is apparent that a birds’ journey is a superb phenomenon in nature. This article will shed more light on why birds select specific migration paths, immigration periods, and even its importance. It will also touch on the challenges that the avian creatures face during migration and how human activities threaten this vital part of the global ecosystem.
Why Birds Choose Particular Paths for Migration
Bird movement is a routine and season-based movement of birds, typically between their wintering and breeding grounds. Birds make use of particular flyways when relocating. A staggering number of bird species engage in immigration, and it has been witnessed and recorded by human beings for thousands of years.
Migratory birds have particular routes that they follow in this movement, and these paths are referred to as flyways. In most cases, the voyage pattern is in such a way that the birds fly north when it is spring for breeding in the Arctic then return to the wintering grounds in the south during autumn. That applies to the northern hemisphere as it is the opposite in the southern hemisphere.
Birds select flyways that are most likely to lead them to places where there is abundant food, shelter, or conducive weather. The presence or lack of natural obstacles along the route is another factor that determines the selection of a flyway by the birds.
Birds prefer routes that align with natural geographical features like rivers, coastlines, or mountain ranges. This way, they can take advantage of the updrafts, thermal columns, or other wind configurations that allow them to expend less energy while in flight.
In Central Asia and Europe, many species of birds engage in immigration, but some truly stand out. An example is a Northern Wheatear (Oenanthe Oenanthe), which migrates from the northern end of Russia all across Central Asia to cross Arabia into the Horn of Africa to southern Africa.
Then there is also the ruff (Philomachus pugnax), which commences its journey in Russia’s northern edge all across northern Europe, passing the Scandinavian nations to enter France, Portugal, Spain, then cross the Mediterranean to reach West Africa after flying over the Sahara Desert.
Periods of Migration
Bird journey overall is a season-based movement via a flyway between the grounds used for breeding and wintering. The journey’s specific timing depends on several factors, with the variation in day length being the most important. To navigate and reach their destination, immigrating birds use the planet’s magnetic field, the pattern of celestial bodies like the stars and the sun, and their memory. Overall, the changes in season determine the precise period in which migration will begin and stop.
Importance of Migration
The main factor that triggers the movement of birds is the presence of food. Other factors that influence migration include habitat or even changes in the weather. Breeding is another primary reason why birds relocate. They move to regions where their young have the best chances of surviving while they are being raised.
Challenges Birds Face During Migration
Even though birds’ journey can be a very spectacular sight to behold, birds face many challenges along the way when migrating between grounds. Unknown to many, migration comes with a very high level of the death rate among birds because they are subjected to predators’ antics and even hunted down by humans. Natural predators like Eleonora’s falcon often target these masses of birds for their consumption.
But being hunted down for food by other animals or human beings is not the only obstacle that the avian creatures have to contend with. There is also the genuine problem of the destruction of habitats. This particular hits immigrating birds in a big way regarding their stopover points and wintering grounds.
Areas that birds used for stopovers during migration or wintering have been taken over by humans and used for construction. This is particularly true of regions where vast wind farms and electricity lines have been put in place. Erecting these structures means destroying the natural habitat that the birds depended on.
Considering the vast distances that birds have to cover during the journey, they also experience stress, which takes a toll on their physical health.
How Humans are Making Migration More Difficult for Birds
Anthropogenic (human-caused) factors are contributing to a lot of problems for birds. Our activities as humans on this planet constitute a real threat to several species of migratory birds. As birds have to cross different countries, they are subjected to illegal hunting practices in several places.
In addition to these, structures like offshore rigs for drilling of oil, wind farms with massive windmills and power lines all have adverse effects on birds. Environmental pollution, destruction of habitat, and wildfires all constitute hazards for these birds. Like with the East Asian-Australasian Flyway, almost 70% of the habitat has been wiped out due to human activities.