C. Animals move from one place to another in search of favourable
environment.
Write about migration of following animals:
a) Arctic tern
b) Salmon fish
c) Monarch butterflies
Answers
Explanation:
1.Arctic terns :(Sterna paradisaea) are small, plain-looking birds, weighing between 90–120 grams (3.2–4.2 ounces) with a wing span of 64–76 centimeters (25.2–29.9 inches). To the untrained eye, they do not look as if they are built for endurance, but these birds take the trophy for the longest migration of any animal in the world.
Flying from pole to pole, Arctic terns spend most of their year at sea chasing a perpetual summer. Seasons are reversed in the Northern and Southern hemispheres, so as winter approaches in their Arctic breeding grounds, the terns head south to the Antarctic where summer is just beginning. Arctic terns are believed to migrate around 40,000 kilometers (25,000 miles) a year, but a recent scientific study suggests that they might fly double that distance.
2.Salmon: (Salmo salar) spend most of their lives in the Atlantic and Pacific oceans, where they feed and grow before migrating back to the rivers where they were born. Salmon swim across the ocean to the mouth of the river, navigating using a combination of chemical cues, the sun, and the Earth’s magnetic field. To reach their final destination, the salmon must swim up the river, in an event known as ‘the salmon run’. In an incredible feat of endurance, they swim up to 400 kilometers (250 miles) against the current, battling rapids and leaping up waterfalls, all while avoiding predators that congregate along the banks in hopes of catching a nutritious meal. When they finally reach their birth place, the salmon spawn and then die.
3.Monarch butterflies:Perhaps one of the most famous migrations is the multi-generational round trip of the monarch butterfly. Monarch butterflies (Danaus plexippus) can be found all over the United States and further afield, but it is the northeastern American population that is famous for making the 4,800-kilometer (3,000-mile) journey from Canada to Mexico.