Birds that go away from their home habitat because of the extreme wether condition that they can't bare are called migratory birds. They return from the place they went during the extreme wether to their natural habitat. 

Migratory Birds

Migratory birds are a fascinating group of birds that undertake regular seasonal movements between their breeding and non-breeding habitats. These birds travel long distances, often crossing international borders, in search of suitable breeding grounds, foraging areas, and favorable climate conditions. They follow well-established migration routes and have the ability to navigate accurately over vast distances.

Reasons for Migration
- Breeding: Many migratory birds travel to specific locations to breed as they require suitable conditions such as abundant food, nesting sites, and safe environments for raising their young.
- Food Availability: Some birds migrate to areas where food sources are more abundant during specific seasons. They follow the availability of insects, fruits, seeds, or nectar.
- Climate: Birds often migrate to escape harsh weather conditions, such as extreme cold, drought, or lack of food, which may occur in their breeding or non-breeding habitats.

Migratory Routes
- Flyways: Migratory birds generally follow specific routes known as flyways. There are four major flyways: Pacific, Central, Mississippi, and Atlantic. These flyways provide important stopover points where birds can rest and refuel during their long journeys.
- Navigation: Migratory birds use various cues for navigation, including the position of the sun, stars, Earth's magnetic field, landmarks, and even their sense of smell and memory. They have the ability to sense the Earth's magnetic field, which helps them maintain a consistent direction.

Examples of Migratory Birds
- Arctic Tern: This bird holds the record for the longest migration, traveling from the Arctic to the Antarctic and back each year, covering a distance of around 70,900 km.
- Bar-headed Goose: Known for its high-altitude migration, it flies over the Himalayas at altitudes of up to 6,000 meters while migrating between its breeding grounds in Central Asia and wintering grounds in India.
- Ruby-throated Hummingbird: These tiny birds migrate across the Gulf of Mexico, flying non-stop for up to 24 hours, to reach their breeding grounds in North America.

Conservation
Migratory birds face numerous threats along their migration routes, including habitat loss, climate change, pollution, hunting, and collisions with structures such as buildings and wind turbines. International efforts are being made to protect and conserve migratory bird populations through the establishment of protected areas, conservation agreements, and awareness campaigns.

Overall, migratory birds play a crucial role in maintaining biodiversity and ecosystem balance. Their remarkable journeys inspire awe and highlight the interconnectedness of habitats across the globe.