Migration: When And Why It Happens

With the changing of the seasons it is easy to see flocks of birds plowing the skies or flocks of marine animals that move for miles in search of warmer waters in which to reproduce. Migratory phenomena in animals are absolutely wonderful events, and today we want to deepen this topic with you.

What are migratory phenomena in animals?

It is essentially the movement from one habitat to another by different species of animals, terrestrial, marine or birds. When the movement is mass, one can speak of emigration or invasion.

Any migration involves a prolonged shift for several days or weeks. Small animals, such as amphibians, take advantage of the water currents, while birds are helped by trade winds or ascending air flows.

Migratory phenomena can have different objectives, for example to move away from extreme temperatures (too hot or too cold), reach a better place to reproduce, escape from predators or get food.

To this day it is still a huge mystery to humans how animals orient themselves when they migrate. Some use the sun as a compass, others the stars, and some theories claim that they are based on the Earth’s magnetic field. Some animals even manage to orient themselves based on the olfactory tracks.

Migration: the most curious cases

There are various species of the animal kingdom – including birds, invertebrates, mammals, amphibians, fish and reptiles – which, during their lifetime, undergo at least one migration. However, the most noteworthy migrations are the following:

1. Sea turtles

Turtles are believed to be the queens of migration. There are two species that make very long crossings during their long life: the first is the common turtle, which is born on the coasts of Japan and swims across the Pacific Ocean to Mexico to feed. He then returns to his homeland to mate and lay eggs. The journey he makes reaches almost 13,000 km in just one year.

The second is the Leatherback Turtle, which is born in the Caribbean and then travels along the coasts of North America to feed on jellyfish. When she is not lucky in her hunt, she crosses the Atlantic Ocean to Africa on a journey of more than 16,000 kilometers.

2.Bald sea eagle

They are the only sea eagles in North America, and each year they flock to the branches of spruce and poplar trees in an area located in the middle of Vancouver, Canada. They feed on the salmon as they try to climb the icy streams of the region. In just one week it is possible to see more than 1500 White-headed Sea Eagles wandering around the area.

3.Balene

As far as migration and sea animals are concerned, the whale is the mammal that makes the longest journey. The Right Whale leaves the South Pole and crosses all of South America until it reaches the north of Costa Rica. Thereafter, it returns to its place of origin, completing a route of no less than 17,000 kilometers.

In the case of the Southern Right Whale, migration is aimed at feeding and reproduction. For this phenomenon, they choose the Valdés Peninsula, Argentina, which they reach in September and October. After mating they leave the area and, although scientists have not yet been able to identify which route they follow, it is believed that they skirt the south of the American continent to follow towards the warmer shores of the Caribbean.

4. Antelopes

Approximately one million specimens all cross large tracts of flat land between Tanzania and Kenya, in search of fresh pastures. In reality it is not a normal migration of animals, but a circular journey of 2700 kilometers made throughout the year to find food.

The antelopes are accompanied on many occasions by zebras, moose and gazelles, and of course closely followed by predators (crocodiles, leopards or lions) ready to seize the first opportunity that presents itself to strike.

5. Monarch Butterfly

In addition to being the most “famous” species with its orange colors, it is also one of the breeds of animals that makes a frightening migration. Every October, millions of specimens come to the Pacific Grove area in California to nest in the face of impending winter. After that, travel to the pine and eucalyptus groves of Monterey. It is a wonderful spectacle that almost always takes place at noon.