Live birds

1988/06/01 Angulo Pinedo, Rikardo Iturria: Elhuyar aldizkaria

The common grass (Apus apus), although not a bulging bird, is in the order of the apodiformes. The four front fingers of his legs are extremely weak and if he falls to the ground he cannot fly again. Therefore, on rare occasions, it is only pruned on vertical or inclined surfaces.

Although, when it flies, it mixes with swallows and swallows, it separates from the vein; its long, crouched wings are mowed. It is also larger, as it is between 16 and 17 cm. In some areas of the Basque Country (interior) it also nests tear ( Apus melba). The first of them is larger (21-22 cm), breeding in abrupt and brown soils, with the white bottom.

Usually the common black can fly all day. That's why you can eat, drink and even cover common cespigones without landing. As soon as twilight arrives, it can ascend to high altitude (up to 1000 or 2000 meters), making its typical song (txiirrr, txiiirrr, txiiirrr...! ! ), which when reaching that height reduces the speed to spend the night. On the other hand, ordinary blacks always fly in a group. Rarely you can see a couple or a single copy.

Common sorbells, like swallows, feed on insects in the air, mainly flies, mosquitoes, butterflies, etc.

In bad weather, they make long flights to escape the rain and reach areas with good weather and many winged insects, they stay all day in their nests (except those that have squirrels, that have to look for food).

Normally it feeds at a speed of 40 kilometers per hour, being able to reach speeds of up to 100 kilometers per hour. The common sorbells, if not very hot, will fly from the early morning until noon and in the afternoon again.

Yearly laying in the holes of our houses and between tiles. Nidifica with feather, kicks in the air and a hat that will give the sorbeltz.

In most cases it will spawn the places where it was the previous year.

Normally, the adult male meets in breeding with the same female of the previous year. When emigration begins, they separate each other until they meet the following year.

In the last days of May, in the only nest it makes, it lays 2-3 eggs, with an interval of two or three days between sets. The eggs are white, smooth and glossy.

The incubation period (both parents work in turns) lasts between 14 and 20 days. However, the duration of nesting will depend on the time.

The chicks are nidicolas, without feathers. In 5-8 weeks they will leave the nest to achieve independence. In mid-July many young people migrate, as confirmed by the rings. A chorizo with the Oxford ring, for example, was captured three days later in Madrid. They will not stop flying until they have reached sexual maturity in two years. Year-olds make pairs, but although they build the nest they do not reproduce. In the nest they will be in June and July, and if the following year they are alive they will spawn again.

In Euskal Herria you can see it from May to September. Migratory bird traveling to southern Africa to spend the winter. Common sorbeltz inhabits all over Europe except Iceland and the North. Black-sorrel, on the contrary, is a species of North Africa and the Mediterranean. Before the puppies grow whole, the male leaves the nest, but there will always be a couple to grow. Therefore, you can often see the common grass alone in the first days of August. Normally they grow in places where human beings live, in cities, towns, hamlets, etc. You will rarely see it in its natural environment, that is, in abrupt and stony grounds. Contrary to the common Sorbeltz, Enara and Enara Azpizuria, urbanization, industrialization and its environmental effects are not excessively aggressive, since in the sky of Bilbao it is also common to see it in light and loose air games.