Willow Sparrow

from Wikipedia, the free encyclopedia
Willow Sparrow
Willow Sparrow (Passer hispaniolensis), male

Willow Sparrow ( Passer hispaniolensis ), male

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Passeroidea
Family : Sparrows (Passeridae)
Genre : Passer
Type : Willow Sparrow
Scientific name
Passer hispaniolensis
( Temminck , 1820)

The willow sparrow ( Passer hispaniolensis ) is a species of sparrow that is widespread in the Mediterranean and temperate parts of South Asia . It is closely related to the house sparrow , with which it also often reproduces and produces hybrids that show the characteristics of both species and correspond in appearance to the Italian sparrow ( Passer italiae ).

There are two or three subspecies, depending on the author.

Appearance

The willow sparrow reaches a height of fifteen centimeters. The males weigh an average of 28.3 grams, the females 28.1 grams. The wingspan is 23 to 26 centimeters.

The male willow sparrow can be identified by a more extensive black on the chest and a brown cap compared to the house sparrow. Its flanks show a black line drawing. The back is also striped; this striation can also be seen in the female, which is difficult to distinguish from the female house sparrow. Occasionally willow sparrows appear as random visitors in Central Europe.

Adult willow sparrows moult about one month after hatching, and young birds about one month after they fled. The moult is over after about 65 days.

distribution and habitat

Distribution area.
Light green: breeding areas of P. h. hispaniolensis
dark green: breeding areas of P. h. transcaspicus
light blue: wintering areas
dusky pink: distribution area of ​​the Italian sparrow.
Other colors show regions in which there are hybrids with other Passer species

The distribution area of ​​the willow sparrow extends over the north of Africa and the south of Europe over Kazakhstan to Afghanistan. Willow sparrows are also found in the Canary Islands, Cape Verde and Madeira.

In Europe it breeds mainly in Spain south of the Ebros , in the Balkans and on most of the Mediterranean islands. On the Balkan Peninsula it has also been found in the humid-temperate zone for several years. The Balkan populations are predominantly short-range migrants with wintering areas on the North African coasts and in individual oasis areas of the Sahara, while the Spanish willow sparrows are mostly resident birds . The Spanish willow sparrows that migrate to northern Africa usually cross the Strait of Gibraltar in small numbers. You leave Europe in late September to early October and then move along the west coast of Morocco. The willow sparrows that breed in the northeastern Mediterranean region usually migrate to the Nile Valley. They stay there from September to April. Willow sparrows breeding in north-west Africa, on the other hand, show very inconsistent migration behavior. They usually overwinter in the transition area to the Sahara and in the interior of Algeria as well as in southern Libya. However, some populations are predominantly resident birds that migrate nomadically to find food sources.

The willow sparrow is a breeding bird of the temperate, summer-dry steppe and desert regions. It colonizes mostly open, often mountainous regions, provided there is water nearby. It occurs in thickets, on bushy terrain, in field trees and groves as well as fig, palm and eucalyptus plantations. The willow sparrow can also be found in wadis, on reforestation areas with French tamarisk , oases, alluvial areas, reed beds, along drainage channels and hedges next to grain fields.

Way of life

Male of the willow sparrow

Willow sparrows are very sociable birds all year round. They nest in large colonies and look for food in schools outside of breeding season, which can contain several thousand individuals. The swarms are bigger, the more food is available. However, they can occasionally be observed individually or in pairs, as well as small groups of ten to 200 birds. Outside the breeding season, they are occasionally associated with finches, house sparrows and desert sparrows . Willow sparrows that have fledged regularly form their own swarms, which also migrate far in search of food. During the rest phases, willow sparrows often sit close together in trees and bushes. They leave their resting place at sunrise, they first circle over the resting place before leaving it. You will return to these resting places around sunset.

In the regions in which its range overlaps with the house sparrow, the willow sparrow is a rather shy bird that flies up immediately when disturbed. In contrast, where the house sparrow is absent, the willow sparrow is much more familiar and can also be found in inner-city regions. He finds his food mainly on the ground. He also examines the foliage of bushes and trees for insects.

food

Willow sparrows mainly eat grass and grain seeds. Among other things, they eat wheat, oats, barley and millet. They also eat young leaves as well as fruits and insects. The nestlings are mainly fed large insect larvae, but occasionally also young leaves, freshly germinated plants and soft seeds.

Reproduction

Willow Sparrow nest in Algeria
Willow sparrow in a swallow's nest on the island of Lesbos
Passer hispaniolensis

Willow sparrows usually enter into a monogamous couple relationship, but it is not yet known whether the couple relationship lasts longer than a breeding attempt. They nest in colonies, and the nests are often close together. The colonies can consist of a few pairs up to many thousands. One breeding colony was observed in Morocco in the 1950s with around 125,000 nests on 60 hectares. There were up to 50 nests in a single tree. Reports of breeding colonies of this size are the exception: it was not until the 1980s that a breeding colony with 4,678 nests was counted in Algeria again. At the time, a total of 35,000 pairs of willow sparrows were breeding in 13 colonies in an area that stretched over 40,000 square kilometers. This resulted in 0.9 breeding pairs per square kilometer. The breeding sites are often used for several years and the second breeding attempt also takes place at this point. Occasionally, however, willow sparrows move to another region for the second brood in order to find new feeding grounds.

The territorial behavior of the breeding pairs is limited to the immediate nest environment. Willow sparrows raise between one and three broods in a year. At the beginning of the breeding season the male either occupies an old nest from the previous year or builds a new one. He tries to attract a female by singing. The pair bonding process takes place within a few days, once the female accepts the nesting site, it is complete.

The nest is loosely put together from grass, straw, twigs and leaves and other plant material. The actual nesting trough is lined with fine plant material, feathers and hair. The nest has a diameter of 15 to 30 centimeters and weighs an average of 150 grams. It is found on branches in low bushes, in hedges, reed beds, in the crown of palm trees or in tree or rock hollows. Holes on house walls or under roofs are also occasionally used by willow sparrows to create their nests, but this behavior can only be observed if there are no house sparrows in the region. Willow sparrows also breed in old, abandoned nests of house martins and red swallow .

The nest is built in four to seven days, the male first builds alone and then both parent birds after the pairing is complete. The actual nesting trough is predominantly made by the female. In colonies where other males steal nesting material, the male guards the nesting site while the female works alone on the nest. The work on the nest continues even after the hatching business has started.

Willow sparrows start laying eggs when the nest is ready or almost ready. The clutch usually consists of four to six eggs, one day apart. The brood is taken in before the clutch is complete. Both parent birds are involved in the brood. The breeding season is 11 to 11.5 days. The nestlings are initially fledged by both parent birds; however, the female has the greater share. Both parent birds feed the nestlings, and both are equally involved. The young birds fledge after about 15 days and are cared for by the parent birds for another four to five days.

The breeding success is sometimes very high. In Morocco, in 95 nests observed, between one and five nestlings fledged per nest. In Algeria at least one young bird per nest fledged out of 4023 clutches. The barn owl is one of the predators . Nestlings are eaten by snakes of the genus Elapha as well as by cattle egrets .

Duration

The European breeding population is estimated at around 2.7 to 6.0 million breeding pairs at the beginning of the 21st century. Countries with more than 200,000 breeding pairs include Turkey, Bulgaria, Greece, the Azores and Italy.

Subspecies

Males and females in Turkey
male

The nominate form Passer hispaniolensis hispaniolensis occurs in southwestern Europe and in western Morocco to northern Sudan. Passer hispaniolensis transcapius is native to Egypt and Sudan. In the male, the plumage is paler overall. The under tail-coverts and the feathers on the back and rump have paler gray-brown feather edges. The subspecies Passer hispaniolensis italiae is native to Morocco, Algeria, Tunisia and Libya. The male's head and upper body correspond to those of the nominate form, but the black plumage is lower on the lower body. The stripes on the flanks and on the lower chest are less pronounced than in the nominate form.

Systematics

The willow sparrow was long considered a subspecies of the house sparrow, today the willow sparrow is seen as a separate species. Both species live largely sympatric on the Iberian peninsula , the Balkans and parts of North Africa without hybridization , which is evidence of the independence of the species . The plumage of the males and the vocalizations differ significantly from each other, but ecologically and nutritionally the species are largely the same. In the common area of ​​distribution, the house sparrow occupies cities and towns and “leaves” the rural habitats to the willow sparrow. If both species occur alone, however, they occupy a similar ecological spectrum. Differences in plumage characteristics, nest construction, voice and migratory behavior are viewed as ethological isolation mechanisms. Above all in eastern Algeria and Tunisia , however, these isolation barriers seem to have largely collapsed in places, due to the hybridization there are sparrow populations that are very variable in terms of appearance and characteristics.

The Italian sparrow is also sometimes viewed as a hybrid of the house and willow sparrow. Even if molecular biological studies are contradicting today, there is much to be said for the classification of the Italian sparrow as a subspecies of the willow sparrow. This is also indicated by the fact that, in contrast to the abrupt geographical exclusion of Italian and house sparrows in the Alpine region, Italian and willow sparrows in central and southern Italy are connected by a broad, flowing transition zone (for more see Italian sparrow ).

Subspecies

There are two known subspecies:

Willow sparrow and human

The willow sparrows, which are actually not very common in Europe, have become a problem in some regions. In the Estremadura , where rice is grown after the implementation of irrigation projects, they are considered a major pest. Willow sparrows are breeding birds of the summer-dry steppe and desert regions. They use the short vegetation phase after rainfall to raise their brood. After successfully rearing a clutch, they move further north to find suitable breeding areas there. By the time they have reached the northern limit of their range, their population may therefore have risen sharply. For Kazakhstan, the number of birds found in one square kilometer has been estimated at up to 2.5 million individuals. Such large population numbers make effective measures against damage to grain fields almost impossible. The cultivation of wheat is therefore hardly economically feasible in these regions.

In Tunisia, the destruction of the willow sparrow's nests has been mandatory since 1892, but it is also practiced to a relatively large extent. Whether this regulation has any major effects on the population has not yet been conclusively investigated.

supporting documents

literature

Single receipts

  1. ↑ H.-G. Bauer, E. Bezzel, W. Fiedler (Hrsg.): The compendium of the birds of Central Europe: Everything about biology, endangerment and protection. Volume 2: Passeriformes - passerine birds. 2005, p. 453.
  2. ↑ a b c d C. Hilary Fry, Stuart Keith (Ed.): The Birds of Africa. Volume VII, 2004, p. 28.
  3. ^ C. Hilary Fry, Stuart Keith (Eds.): The Birds of Africa. Volume VII, 2004, p. 24.
  4. ↑ a b c d C. Hilary Fry, Stuart Keith (Ed.): The Birds of Africa. Volume VII, 2004, p. 25.
  5. ^ C. Hilary Fry, Stuart Keith (Eds.): The Birds of Africa. Volume VII, 2004, p. 25 and p. 28.
  6. ^ C. Hilary Fry, Stuart Keith (Eds.): The Birds of Africa. Volume VII, 2004, pp. 28-29.
  7. ↑ a b c C. Hilary Fry, Stuart Keith (Ed.): The Birds of Africa. Volume VII, 2004, p. 29.
  8. ↑ H.-G. Bauer, E. Bezzel, W. Fiedler (Hrsg.): The compendium of the birds of Central Europe: Everything about biology, endangerment and protection. Volume 2: Passeriformes - passerine birds. 2005, p. 454.
  9. ↑ a b HBV Volume 14/1, P. domesticus. Pp. 35-45.
  10. ↑ Einhard Bezzel: Compendium of the birds of Central Europe. Volume II, pp. 584-589.
  11. ^ Till Töpfer: The taxonomic status of the Italian Sparrow - Passer italiae (Vieillot 1817): Speciation by stabilized hybridization? A critical analysis. In: Zotaxa. 1325, 2006, pp. 117-145. ( Summary (PDF file; 18 kB))
  12. ^ IOC World Bird List Old World sparrows, snowfinches & weavers
  13. ↑ JD Summers-Smith: On Sparrows and Man - A Love-Hate Relationship. 2005, p. 60 and p. 61.

Web links

Commons : Willow Sparrow  - Album with pictures, videos and audio files