Lesser Whitethroat
Encyclopedia
The Lesser Whitethroat (Sylvia curruca) is a common and widespread typical warbler
which breeds in temperate Europe
, except the southwest, and in western and central Asia
. This small passerine
bird
is strongly migratory
, wintering in Africa
just south of the Sahara
, Arabia
and India
.
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Unlike many typical warblers, the sexes are almost identical. This is a small species
with a grey back, whitish underparts, a grey head with a darker "bandit mask" through the eyes and a white throat. It is slightly smaller than the Whitethroat
, and lacks the chestnut wings and uniform head-face color of that species. The Lesser Whitethroat's song is a fast and rattling sequence of tet or che calls, quite different from the Whitethroat's scolding song.
Like most "warblers", it is insectivorous, but will also take berries
and other soft fruit
. This is a bird
of fairly open country and cultivation, with large bushes for nesting and some trees. The nest is built in low shrub or brambles, and 3–7 egg
s are laid.
, from a specimen collected in southern Sweden
.
This species has been commonly assumed to be closely related to the Whitethroat
, as their common names imply. It was suggested that the two species separated in the last ice age similar to the pattern found in the Chiffchaff
and Willow Warbler
, with their ancestor being forced into two enclaves, one in the southeast and one in the southwest of Europe. When the ice sheets retreated, the two forms supposedly no longer recognised each other as the same species. However, scientists researching this question have for quite some time realized that these two taxa are not particularly close relatives.
Rather, the Lesser Whitethroat and its closest relatives Hume's Whitethroat
and the Small Whitethroat
appear more related to a group of morphologically
quite dissimilar species. These vary much in size and color pattern, but also lack chestnut wing patches and have a strong contrast between the usually dark head sides and the white or whitisch throat. The latter group occurs from the southern parts of the Lesser Whitethroat complex' range into Africa and include the Orphean Warbler
group, the Arabian Warbler, and the Brown
and Yemen Warblers sometimes placed in Parisoma. Thus, it rather appears as if the divergence of the Lesser Whitethroat complex and its closest living relatives is more ancient than assumed, and that it did not involve separation by ice sheets building up in Europe, but by arid
ification of the Arabian region (which also occurred throughout the Ice Ages).
The Lesser Whitethroat complex has been split up into the present species, Hume's Whitethroat, and the Small Whitethroat from which the Margelanic Whitethroat may also be specifically distinct. In this superspecies
, the Lesser Whitethroat seems to form the basal
European lineage. Only two subspecies
are nowadays unequivocally recognized for the Lesser Whitethroat, and they intergrade throughout Central Europe:
Two more taxa occur in the intergradation zone with the Small Whitethroat, stretching from the northern Caspian Sea
area into Mongolia
. The phylogeny of these is not well-researched, and they might eventually turn out to belong to either species or be stereotyped hybrids:
Similarly, Sylvia curruca caucasica is intermediate between the Lesser and Hume's Whitethroats.
A bird which wintered at Landsort
Bird Observatory, Sweden
, differed in the analyzed mtDNA sequences from all known taxa in the complex, although it most closely resembled halimodendri in the field. As mtDNA is inherited from the mother only, were this bird a hybrid this should have been recognizable.
Typical warbler
The typical warblers are small birds belonging to the genus Sylvia in the "Old World warbler" family Sylviidae. There are 28 species currently included in the genus, including five species formerly treated in the genus Parisoma, a treatment which left Sylvia paraphyletic...
which breeds in temperate Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, except the southwest, and in western and central Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. This small passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
is strongly migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, wintering in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
just south of the Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
, Arabia
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
and India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
with a grey back, whitish underparts, a grey head with a darker "bandit mask" through the eyes and a white throat. It is slightly smaller than the Whitethroat
Whitethroat
The Common Whitethroat, Sylvia communis, is a common and widespread typical warbler which breeds throughout Europe and across much of temperate western Asia. This small passerine bird is strongly migratory, and winters in tropical Africa, Arabia and Pakistan.This is one of several Sylvia species...
, and lacks the chestnut wings and uniform head-face color of that species. The Lesser Whitethroat's song is a fast and rattling sequence of tet or che calls, quite different from the Whitethroat's scolding song.
Like most "warblers", it is insectivorous, but will also take berries
Berry
The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
and other soft fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
. This is a bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
of fairly open country and cultivation, with large bushes for nesting and some trees. The nest is built in low shrub or brambles, and 3–7 egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s are laid.
Taxonomy
This species was first described by Carl Linnaeus in his 1758 edition of Systema NaturaeSystema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
, from a specimen collected in southern Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
.
This species has been commonly assumed to be closely related to the Whitethroat
Whitethroat
The Common Whitethroat, Sylvia communis, is a common and widespread typical warbler which breeds throughout Europe and across much of temperate western Asia. This small passerine bird is strongly migratory, and winters in tropical Africa, Arabia and Pakistan.This is one of several Sylvia species...
, as their common names imply. It was suggested that the two species separated in the last ice age similar to the pattern found in the Chiffchaff
Chiffchaff
The Common Chiffchaff, or simply the Chiffchaff, is a common and widespread leaf-warbler which breeds in open woodlands throughout northern and temperate Europe and Asia....
and Willow Warbler
Willow Warbler
The Willow Warbler is a very common and widespread leaf warbler which breeds throughout northern and temperate Europe and Asia, from Ireland east to the Anadyr River basin in eastern Siberia...
, with their ancestor being forced into two enclaves, one in the southeast and one in the southwest of Europe. When the ice sheets retreated, the two forms supposedly no longer recognised each other as the same species. However, scientists researching this question have for quite some time realized that these two taxa are not particularly close relatives.
Rather, the Lesser Whitethroat and its closest relatives Hume's Whitethroat
Hume's Whitethroat
Hume's Whitethroat Sylvia althaea is a species of typical warbler. Until recently, it was considered conspecific with the Lesser Whitethroat; today these are seen as members of a superspecies which also includes the Desert Whitethroat...
and the Small Whitethroat
Small Whitethroat
The Desert Whitethroat is a typical warbler. Until recently, it was considered conspecific with the Lesser Whitethroat; today these are seen as members of a superspecies...
appear more related to a group of morphologically
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
quite dissimilar species. These vary much in size and color pattern, but also lack chestnut wing patches and have a strong contrast between the usually dark head sides and the white or whitisch throat. The latter group occurs from the southern parts of the Lesser Whitethroat complex' range into Africa and include the Orphean Warbler
Orphean Warbler
The Orphean Warbler, Sylvia hortensis, is a typical warbler of the genus Sylvia. This species occurs in summer around the Mediterranean, through Turkey and the Caucasus and extending into Central Asia. It is migratory, wintering in sub-Saharan Africa...
group, the Arabian Warbler, and the Brown
Brown Warbler
The Brown Parisoma or Brown Warbler is a typical warbler found in Africa....
and Yemen Warblers sometimes placed in Parisoma. Thus, it rather appears as if the divergence of the Lesser Whitethroat complex and its closest living relatives is more ancient than assumed, and that it did not involve separation by ice sheets building up in Europe, but by arid
Arid
A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...
ification of the Arabian region (which also occurred throughout the Ice Ages).
The Lesser Whitethroat complex has been split up into the present species, Hume's Whitethroat, and the Small Whitethroat from which the Margelanic Whitethroat may also be specifically distinct. In this superspecies
Superspecies
A superspecies is a group of at least two more or less distinctive species with approximately parapatric distributions. Not all species complexes, whether cryptices or ring species are superspecies, and vice versa, but many are...
, the Lesser Whitethroat seems to form the basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
European lineage. Only two subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
are nowadays unequivocally recognized for the Lesser Whitethroat, and they intergrade throughout Central Europe:
- Sylvia curruca curruca – Western Lesser Whitethroat – western parts of range
- Sylvia curruca blythi – Northeastern Lesser Whitethroat – eastern parts of range. Has somewhat paler top of head, separated from face sides by white superciliumSuperciliumThe supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...
.
Two more taxa occur in the intergradation zone with the Small Whitethroat, stretching from the northern Caspian Sea
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...
area into Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
. The phylogeny of these is not well-researched, and they might eventually turn out to belong to either species or be stereotyped hybrids:
- Sylvia curruca/minula halimodendri
- Sylvia curruca/minula telengitica
Similarly, Sylvia curruca caucasica is intermediate between the Lesser and Hume's Whitethroats.
A bird which wintered at Landsort
Landsort
Landsort, is a Swedish village and a lighthouse on the island of Öja. The tower was built in 1689, with an upper conical iron section added in 1870. Open fires have been lit here since a long time ago....
Bird Observatory, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
, differed in the analyzed mtDNA sequences from all known taxa in the complex, although it most closely resembled halimodendri in the field. As mtDNA is inherited from the mother only, were this bird a hybrid this should have been recognizable.