Hume's Leaf Warbler
Encyclopedia
Hume's Leaf-warbler or Hume's Warbler (Phylloscopus humei) is a small leaf warbler
which breeds in the mountains of inner Asia
. This warbler is migratory
and winters mainly in India
.
This bird is named after Allan Octavian Hume
. Like most similar songbird
s, it was formerly included in the "Old World warbler
" assemblage.
s". Like most other leaf warbler
s, it has greenish upperparts and off-white underparts. With its long supercilium
, crown stripe and yellow-margined tertial remiges, it is very similar to the Yellow-browed Warbler
(P. inornatus). However, it has only one prominent light wing bar, just a faint vestige of the second shorter wing bar, and overall duller colours. It also has a dark lower mandible
and legs.
Its song is buzzing and high pitched. The best distinction from the Yellow-browed Warbler is the more disyllabic call. While the Eastern and Western Hume's Leaf Warblers already show noticeable differences in mtDNA sequence
and calls, their songs do not differ; they are reproductively isolated only by allopatry and not usually considered separate species.
of mountain woodlands at altitudes of up to 3,500m ASL
. It occurs from the Hindu Kush
and Karakoram
east and north to the Tien Shan in China
and the Altay Mountains
in Mongolia
. The completely allopatric subspecies
mandellii (Mandell's Leaf-warbler or Eastern Hume's Warbler) – sometimes separated as a full species
, in which case the nominate subspecies is called Western Hume's Warbler – occurs on the eastern Tibetan Plateau
. Both populations migrate
over the Himalayas
to winter in India
and adjacent regions. The species has also been recorded in the Kutch region.
Particularly on autumn migration, this tiny warbler is prone to vagrancy as far as western Europe
, despite a 3,000 km distance from its breeding grounds. It is a rare vagrant in late autumn and winter in Great Britain
. Non-breeding adults may stray around a lot in summer, when Mandell's Leaf-warblers are fairly common summer visitors to subtropical and temperate
montane
humid forests of Bhutan
, around 2,000-3,500 m ASL
and dominated by Bhutan Fir (Abies densa) or by Himalayan Hemlock (Tsuga dumosa) and rhododendron
s, though the subspecies is not a regular breeder in that country.
This bird is not shy, although its arboreal lifestyle and cryptic
colours make it difficult to observe. It is constantly in motion. Like most "Old World warbler
s", this small passerine
is insectivorous. The nest is built on the ground.
A common species in most of its wide range, Hume's Leaf-warbler is not considered threatened by the IUCN.
It was recently split from the Yellow-browed Warbler
(Phylloscopus inornatus), based on differences in morphology
, bioacoustics
, and molecular characters. The Western Hume's Leaf Warbler's range overlaps with that of the Yellow-browed Warbler in the western Sayan Mountains
, but the species apparently do not hybridize. The divergence between the two species has been tentatively estimated at roughly 2,5 million years ago (Ma), and that between P. h. humei and P. h. mandelli at about 1 mya.
Leaf warbler
Leaf-warblers are small insectivorous birds belonging mainly to the genus Phylloscopus. They were formerly included in the Old World warbler family but are now considered to belong to the Phylloscopidae, a family created in 2006. The genus is closely related to Seicercus and some species have been...
which breeds in the mountains of inner 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 warbler is 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...
and winters mainly in 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...
.
This bird is named after Allan Octavian Hume
Allan Octavian Hume
Allan Octavian Hume was a civil servant, political reformer and amateur ornithologist in British India. He was one of the founders of the Indian National Congress, a political party that was later to lead the Indian independence movement...
. Like most similar songbird
Songbird
A songbird is a bird belonging to the suborder Passeri of the perching birds . Another name that is sometimes seen as scientific or vernacular name is Oscines, from Latin oscen, "a songbird"...
s, it was formerly included in the "Old World warbler
Old World warbler
The "Old World Warblers" is the name used to describe a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the cisticolas into...
" assemblage.
Description
Hume's Leaf-warbler is one of the smallest "Old World warblerOld World warbler
The "Old World Warblers" is the name used to describe a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the cisticolas into...
s". Like most other leaf warbler
Leaf warbler
Leaf-warblers are small insectivorous birds belonging mainly to the genus Phylloscopus. They were formerly included in the Old World warbler family but are now considered to belong to the Phylloscopidae, a family created in 2006. The genus is closely related to Seicercus and some species have been...
s, it has greenish upperparts and off-white underparts. With its long supercilium
Supercilium
The 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...
, crown stripe and yellow-margined tertial remiges, it is very similar to the Yellow-browed Warbler
Yellow-browed Warbler
The Yellow-browed Warbler is a leaf warbler which breeds in temperate Asia. This warbler is strongly migratory and winters mainly in tropical southeast Asia, but also in small numbers in western Europe...
(P. inornatus). However, it has only one prominent light wing bar, just a faint vestige of the second shorter wing bar, and overall duller colours. It also has a dark lower mandible
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
and legs.
Its song is buzzing and high pitched. The best distinction from the Yellow-browed Warbler is the more disyllabic call. While the Eastern and Western Hume's Leaf Warblers already show noticeable differences in mtDNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
and calls, their songs do not differ; they are reproductively isolated only by allopatry and not usually considered separate species.
Ecology and evolution
This is a common birdBird
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 mountain woodlands at altitudes of up to 3,500m ASL
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
. It occurs from the Hindu Kush
Hindu Kush
The Hindu Kush is an mountain range that stretches between central Afghanistan and northern Pakistan. The highest point in the Hindu Kush is Tirich Mir in the Chitral region of Khyber-Pakhtunkhwa, Pakistan.It is the westernmost extension of the Pamir Mountains, the Karakoram Range, and is a...
and Karakoram
Karakoram
The Karakoram, or Karakorum , is a large mountain range spanning the borders between Pakistan, India and China, located in the regions of Gilgit-Baltistan , Ladakh , and Xinjiang region,...
east and north to the Tien Shan in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and the Altay Mountains
Altay Mountains
The Altai Mountains are a mountain range in East-Central Asia, where Russia, China, Mongolia and Kazakhstan come together, and where the rivers Irtysh and Ob have their sources. The Altai Mountains are known as the original locus of the speakers of Turkic as well as other members of the proposed...
in 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 completely allopatric 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...
mandellii (Mandell's Leaf-warbler or Eastern Hume's Warbler) – sometimes separated as a full species
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...
, in which case the nominate subspecies is called Western Hume's Warbler – occurs on the eastern Tibetan Plateau
Tibetan Plateau
The Tibetan Plateau , also known as the Qinghai–Tibetan Plateau is a vast, elevated plateau in Central Asia covering most of the Tibet Autonomous Region and Qinghai, in addition to smaller portions of western Sichuan, southwestern Gansu, and northern Yunnan in Western China and Ladakh in...
. Both populations migrate
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...
over the Himalayas
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
to winter in 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...
and adjacent regions. The species has also been recorded in the Kutch region.
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...
, despite a 3,000 km distance from its breeding grounds. It is a rare vagrant in late autumn and winter in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
. Non-breeding adults may stray around a lot in summer, when Mandell's Leaf-warblers are fairly common summer visitors to subtropical and temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
montane
Montane
In biogeography, montane is the highland area located below the subalpine zone. Montane regions generally have cooler temperatures and often have higher rainfall than the adjacent lowland regions, and are frequently home to distinct communities of plants and animals.The term "montane" means "of the...
humid forests of Bhutan
Bhutan
Bhutan , officially the Kingdom of Bhutan, is a landlocked state in South Asia, located at the eastern end of the Himalayas and bordered to the south, east and west by the Republic of India and to the north by the People's Republic of China...
, around 2,000-3,500 m ASL
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
and dominated by Bhutan Fir (Abies densa) or by Himalayan Hemlock (Tsuga dumosa) and rhododendron
Rhododendron
Rhododendron is a genus of over 1 000 species of woody plants in the heath family, most with showy flowers...
s, though the subspecies is not a regular breeder in that country.
This bird is not shy, although its arboreal lifestyle and cryptic
Crypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
colours make it difficult to observe. It is constantly in motion. Like most "Old World warbler
Old World warbler
The "Old World Warblers" is the name used to describe a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the cisticolas into...
s", 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...
is insectivorous. The nest is built on the ground.
A common species in most of its wide range, Hume's Leaf-warbler is not considered threatened by the IUCN.
It was recently split from the Yellow-browed Warbler
Yellow-browed Warbler
The Yellow-browed Warbler is a leaf warbler which breeds in temperate Asia. This warbler is strongly migratory and winters mainly in tropical southeast Asia, but also in small numbers in western Europe...
(Phylloscopus inornatus), based on differences in morphology
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....
, bioacoustics
Bioacoustics
Bioacoustics is a cross-disciplinary science that combines biology and acoustics. Usually it refers to the investigation of sound production, dispersion through elastic media, and reception in animals, including humans. This involves neurophysiological and anatomical basis of sound production and...
, and molecular characters. The Western Hume's Leaf Warbler's range overlaps with that of the Yellow-browed Warbler in the western Sayan Mountains
Sayan Mountains
The Sayan Mountains are a mountain range between northwestern Mongolia and southern Siberia, Russia.The Eastern Sayan extends from the Yenisei River at 92° E to the southwest end of Lake Baikal at 106° E...
, but the species apparently do not hybridize. The divergence between the two species has been tentatively estimated at roughly 2,5 million years ago (Ma), and that between P. h. humei and P. h. mandelli at about 1 mya.