Hume's leaf warbler or Hume's warbler (''Phylloscopus humei'') is a small

leaf warbler Leaf warblers are small insectivorous passerine birds belonging to the genus ''Phylloscopus''. Leaf warblers were formerly included in the Old World warbler family but are now considered to belong to the family Phylloscopidae, introduced in 2006 ...

which breeds in the mountains of inner

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. This warbler is migratory and winters mainly in India. The English name and the specific ''humei'' commemorate

Allan Octavian Hume Allan Octavian Hume, Order of the Bath, CB Indian Civil Service, ICS (4 June 1829 – 31 July 1912) was a British political reformer, ornithologist, civil servant and botanist who worked in British Raj, British India and was the founding spirit ...

, a British civil servant and ornithologist based in India. The genus name ''Phylloscopus'' is from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

''phullon'', "leaf", and ''skopos'', "seeker" (from ''skopeo'', "to watch"). Like most similar

songbird A songbird is a bird belonging to the suborder Passeri of the perching birds (Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 5,00 ...

s, it was formerly included in the "

Old World warbler The Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. They are not closely related to the New World warblers. The family held over 400 species in over 70 genera, and were the source of much taxo ...

" assemblage.

Description

Hume's leaf warbler is one of the smallest "

s". Like most other

s, it has greenish upperparts and off-white underparts. With its long

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.Dunn and Alderfer (2006), p. 10 Also k ...

, 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 In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

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 Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

and calls, their songs do not differ; they are reproductively isolated only by

allopatry Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

and not usually considered separate species.

Ecology and evolution

This is a common

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

of mountain woodlands at altitudes of up to 3,500m ASL. It occurs from the

Hindu Kush The Hindu Kush is an mountain range in Central Asia, Central and South Asia to the west of the Himalayas. It stretches from central and eastern Afghanistan into northwestern Pakistan and far southeastern Tajikistan. The range forms the wester ...

and

Karakoram The Karakoram () is a mountain range in the Kashmir region spanning the border of Pakistan, China, and India, with the northwestern extremity of the range extending to Afghanistan and Tajikistan. Most of the Karakoram mountain range is withi ...

east and north to the

Tien Shan The Tian Shan, also known as the Tengri Tagh or Tengir-Too, meaning the "Mountains of God/Heaven", is a large system of mountain ranges in Central Asia. The highest peak is Jengish Chokusu at high and located in Kyrgyzstan. Its lowest point is ...

in China and the

Altay Mountains The Altai Mountains (), also spelled Altay Mountains, are a mountain range in Central and East Asia, where Russia, China, Mongolia, and Kazakhstan converge, and where the rivers Irtysh and Ob have their headwaters. The massif merges with th ...

in Mongolia. The completely

allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

''mandellii'' (Mandell's leaf warbler or eastern Hume's warbler) – sometimes separated as a full

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, in which case the

nominate subspecies In biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. ...

is called western Hume's warbler – occurs on the eastern

Tibetan Plateau The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or Qingzang Plateau, is a vast elevated plateau located at the intersection of Central Asia, Central, South Asia, South, and East Asia. Geographically, it is located to the north of H ...

. Both populations

migrate Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

over the

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

to winter in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

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 The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

and

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

humid Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

forests of

Bhutan Bhutan, officially the Kingdom of Bhutan, is a landlocked country in South Asia, in the Eastern Himalayas between China to the north and northwest and India to the south and southeast. With a population of over 727,145 and a territory of , ...

, around 2,000-3,500m ASL and dominated by Bhutan fir (''Abies densa'') or by Himalayan hemlock (''Tsuga dumosa'') and

rhododendron ''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...

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 "

s", this small

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped') which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their ...

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores we ...

. The nest is built on the ground. A common species in most of its wide range, Hume's leaf-warbler is not considered

threatened A threatened species is any species (including animals, plants and fungi) which is vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensatio ...

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. It was recently split from the yellow-browed warbler (''Phylloscopus inornatus''), based on differences in

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

bioacoustics Bioacoustics is a cross-disciplinary science that combines biology and acoustics. Usually it refers to the investigation of sound production, dispersion and reception in animals (including humans). This involves neurophysiology, neurophysiological ...

, and molecular characters. The western Hume's leaf warbler's range overlaps with that of the yellow-browed warbler in the western

Sayan Mountains The Sayan Mountains (, ; ) are a mountain range in southern Siberia spanning southeastern Russia (Buryatia, Irkutsk Oblast, Krasnoyarsk Krai, Tuva and Khakassia) and northern Mongolia. Before the rapid expansion of the Tsardom of Russia, the mou ...

, but the species apparently do not hybridize. The divergence between the two species has been tentatively estimated at 2.5

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

(mya), and that between ''P. h. humei'' and ''P. h. mandelli'' at about 1 mya.Alström & Olsson (1988), Shirihai & Madge (1993), Ernst (1996), Irwin ''et al.'' (2001), Sangster ''et al.'' (2002)

Footnotes

References

* Alström, Per (2006): Species concepts and their application: insights from the genera ''Seicercus'' and ''Phylloscopus''. ''Acta Zoologica Sinica'' 52(Supplement): 429–434
PDF fulltext
* Alström, Per & Olsson, U. (1988): Taxonomy of Yellow-browed Warblers. '' Brit. Birds'' 81: 656–657. * Ernst, S. (1996): Zweiter Beitrag zur Vogelwelt des Östlichen Altai Second contribution regarding the avifauna of the Sayan Mountains" ''Mitteilungen aus dem Zoologischen Museum Berlin'' 72, ''Suppl. Ann. Ornithol.'' 20: 123–180 rticle in German * Inskipp, Carol; Inskipp, Tim & Sherub (2000): The ornithological importance of Thrumshingla National Park, Bhutan. '' Forktail'' 14: 147–162
PDF fulltext
* Irwin, D.E.; Alström, Per; Olsson, U. & Benowitz-Fredericks, Z.M. (2001): Cryptic species in the genus ''Phylloscopus'' (Old World leaf warblers). ''

Ibis The ibis () (collective plural ibises; classical plurals ibides and ibes) are a group of long-legged wading birds in the family Threskiornithidae that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word f ...

'' 143(2): 233–247. PDF fulltext
* Price, Trevor & Jamdar, N. (1991): Breeding biology of the Yellow-browed leaf warbler ''Phylloscopus inornatus (humei)'' in Kashmir. ''Journal of the Bombay Natural History Society'' 88(1): 1–19. * Sangster, George; Knox, Alan G.; Helbig, Andreas J. & Parkin, David T. (2002): Taxonomic recommendations for European birds. ''

'' 144(1): 153–159. (HTML abstract) * Shirihai, H. & Madge, S. (1993): Identification of Hume's Yellow-browed Warbler. ''

Birding World ''Birding World'' was a monthly birdwatching, birding magazine published in the United Kingdom. It was the magazine of the Bird Information Service, based at Cley next the Sea, Norfolk. With the publication of issue No. 26/12 in January 2014, ''Bi ...

'' 6: 439–443. {{Taxonbar, from=Q608313 Hume's leaf warbler Birds of Asia Hume's leaf warbler