Migration of birds in cold weather
Birds migrate for a variety of reasons, including in order to reproduce, grow, find food, or avoid cold weather, and this happens twice a year, migrating the first time in the spring and the second time in the fall.
Birds are looking for places with warmth, and food, safe for breeding in the southern hemisphere, in tropical climates where it is warm enough, and since there is a slight change in the length of days from month to month birds are able to find sufficient food supply all year round.
It is generally accepted that the presence of constant daylight in some areas gives birds plenty of time to eat every day, so they do not need to go somewhere else to find food.
Each species of bird has its own migration method, some travel in a straight line to their new destination, others follow landmarks; it should be noted that some adhere to flying over land, others cross open water; some also take the same route on the way back and forth.
While others take a completely different route from the one from which they came, and it is easy to identify the landmarks that birds use to guide them, such as following a coastline or a river or using man-made landmarks such as roads and railways.
It is noteworthy that birds have a set of means to help them navigate, such as the sense of smell and magnetic fields, and as for a group of birds that migrate in winter:
A lapwing bird.
Birds of the fields.
Birds of geese.
The mechanism of determining the birds for their destination :
Migratory birds follow specific paths, sometimes they are clearly defined for long distances, and most migratory birds travel through wide air paths, and sometimes a group of them gathers in a vast area forming a wide front that accidentally spreads over hundreds of miles. The conditions of bird migration depend on many factors, such as river systems, valleys, coasts, and ecological conditions, and also depend on weather conditions, as birds change the direction of their migration depending on the direction and strength of the wind.
Many species of birds migrate thousands of kilometers every year in search of weather and food, in the spring the birds migrate to temperate regions where food is abundant, and they may safely build nests, and in the autumn the birds migrate to warmer latitudes following their food sources and more comfortable weather patterns.
The individual organs of the birds contribute to the navigational ability of the bird, as the bird’s eyes interact with its brain in an area called the block, which helps the bird in determining the direction of the North, and small amounts of iron in the neurons of the inner ear of the bird also help in this determination.
It should be noted that the bird’s beak helps birds in migration, as it is able to determine its exact location, and some researchers believe that the bird can smell its way through a flight path, through the nerve that connects the bird’s beak to its brain, where it helps the bird to assess its exact location.
Forms of bird migration :
Migration is spread among many species of birds, but some species of birds do not migrate, and in some species, not all groups of the same species migrate, and in some cases, not all of its members migrate, in some areas, including the British Isles, some birds reside there all year round and do not migrate, while other groups show partial migration patterns.
Other species migrate to escape the winter to other regions, and migration often occurs in birds living in seasonal environments such as the Arctic tundra, because in such environments there is a noticeable difference in food supply throughout the year, turning from abundant during the summer to scarce during the winter.