Chestnut-crowned Bush Warbler Cettia major Scientific name definitions

13 cm; 9·7 g (1 Round, P.D., Ul Haque, E., Dymond, N., Pierce, A.J. and Thompson, P.M. (2014). Ringing and ornithological exploration in north-east Bangladesh wetlands. Forktail. 30: 109–121. Close ). A medium-sized to large bush-warbler with distinctive chestnut crown. Nominate has fairly long inlinemedia warm buff or rufous-buff (and indistinct) in front of eye, whiter behind eye; short diffuse dark eyestripe also more prominent behind eye; cheek and ear-coverts gray, variably mottled brown; forecrown to nape chestnut, upperparts rather dark brownish-olive; whitish below , breast side grayish, flanks brownish-olive; iris dark; bill dark brownish-horn to blackish, pale pinkish base of lower mandible; legs pale pinkish to reddish-pink. Sexes alike. Juvenile lacks chestnut crown, is dark olive-brown above, grayish-buff supercilium behind eye, grayish-olive breast side and mottling across throat and breast, yellowish wash on belly.

Differs from Pale-footed Bush Warbler (Hemitesia pallidipes) in more robust shape, chestnut crown, darker upperparts, brownish-olive flanks; from Gray-sided Bush Warbler (Cettia brunnifrons) in larger size, larger bill, different supercilium pattern.

Along with Gray-sided Bush Warbler (Cettia brunnifrons) and Chestnut-headed Tesia (Cettia castaneocoronata) sometimes placed in Oligura. In past, validity of subspecies vafra sometimes questioned, but plumage differences appear distinct enough.

Himalayas from northern and northeastern India (Uttarakhand, Assam) east to central and eastern Qinghai, southeastern Tibet, Sichuan, northwestern Yunnan (China).

Undergrowth, ground vegetation and thorn-scrub in high-altitude fir forests; shows preference for rhododendron (Rhododendron) shrubberies in silver fir (Abies alba) forest around tree-line and also dwarf rhododendron thickets above tree-line; present at 3300–4000 m at or near tree-line in Himalayas, to c. 2200 m in China, and c. 1800 m in hills of northeastern India. In winter, found in open grassy and scrub areas, often near water, occasionally at edges of forest; lowlands, usually below 250 m.

Altitudinal migrant, descending to lower elevations after breeding season. Occasional longer movements evidently undertaken; vagrant in Bangladesh (Feb 2012) (1 Round, P.D., Ul Haque, E., Dymond, N., Pierce, A.J. and Thompson, P.M. (2014). Ringing and ornithological exploration in north-east Bangladesh wetlands. Forktail. 30: 109–121. Close ) and NW Thailand.

The vocal repertoire of Chestnut-crowned Bush Warbler is little studied and few recordings are available. Its habits are typically skulking in the nonbreeding season and it is usually heard more often than seen. Vocalizations in its wintering range are poorly known and difficult to study owing to the shy and elusive behavior of the species. Additional vocalizations are likely, especially in the breeding season, when the birds are the most vocal.

Development

No information available.

Vocal Array

The Primary Song of the species is well described from its breeding grounds in China (2 Kennerley, P., and D. Pearson (2010). Reed and Bush Warblers. Christopher Helm, London, UK. Close , 3 Rasmussen, P. C., and J. C. Anderton (2012). Birds of South Asia: the Ripley Guide. Volumes 1 and 2. Second edition. National Museum of Natural History, Washington, D.C., USA, Smithsonian Institution, Michigan State University, Ann Arbor, MI, USA, and Lynx Edicions, Barcelona, Spain. Close ), but several components of the vocalizations that were poorly known, especially from the non-breeding season, have been recently described from its wintering grounds in India by Sharma et al. (4 Sharma, P., Laishram, D., & Huidrom, H. (2021). Chestnut-crowned Bush Warbler Cettia major: First records for Manipur, India, and some notes on its vocalisations. Indian BIRDS 17(6): 179–181 Close ); the repertoire description below is adapted from it as well as previous descriptions.

Primary Song. An explosive, excited, chirpy, warbling cluster of 6–8 unique and distinct notes, with a narrow frequency range of 2–5.5 kHz, lasting from 1.70–1.85 seconds. It starts with three, somewhat similar, thin, down-slurred introductory notes given with a slight hesitation, at a relatively higher frequency range 4.5–5.5 kHz, immediately followed by four rapidly warbling, variable notes rising and falling in quality and pitch at 2.2-5.2 kHz; the latter part lending the overall cheery, sweet or pleasant and upbeat quality to the song. In winter, the song is apparently delivered abruptly and inconsistently, usually followed with Tzick calls; given from well-concealed low (1–2 meters) perches in dense foliage early in the mornings, and likely produced only in the presence of conspecifics. In the breeding season, the Primary Song is known to be repeated every 2–3 seconds consistently, for long durations, usually from open or prominent perches.

Chew-chewey-you. A variation of the Primary Song, given as a very shrill, raspy, jumbled warble of a cluster of several slurred notes combined together in an irregular manner at a relatively higher frequency range of 1.5–7.5 kHz, lasting 0.5–2.5 seconds. It probably functions as an alarm or warning, and is uttered throughout the year. It was given abruptly and as a short phrase (0.9 seconds) from wintering grounds in Manipur, India in January from inconspicuous low (1–2 meters) perches in dense foliage. It is otherwise known to be given as a longer phrase (>2 seconds) and repeated consistently every few seconds from the breeding grounds in Sichuan, China from May, when it may likely function as a territorial song. It also preceded the Primary Song in one recording from May.

Tzick. The primary call is a very sharp, jittery, raspy clicking call at 2.5–5.5 kHz, lasting about 0.05 seconds, and repeated every few seconds. It is the most commonly heard call in winter, given in various contexts, usually when foraging, when it is given singly, in well-spaced intervals, in a very calm manner. However, when agitated, alarmed, or excited, it is mostly quickly paired or delivered in a long rapidly slurred, aggressive series; sometimes interspersed with grouping it in shorter series of threes or fours bunched together . Tempo gains rapid momentum during intraspecific interactions, during which two birds would deliver the call series in a more slurred, grating series given in an irregular pattern and more aggressively. One of the birds may also dominate at a higher frequency range at around 4.2–7.3 kHz with calls delivered in a rapidly descending, grating series .

Tsip or Tsweep calls. Thin, penetrating, variable, metallic, buzzy or squeaky calls at around 4.5–7.5 kHz, just under 0.2 seconds, and repeated every few seconds. It is probably a contact or alarm call, typically following the Chew-chewey-you jumbled warble, and also interspersed with Tzick calls, either singly or paired. Some notes of Tsweep calls sound very similar to the call of Gray-sided Bush Warbler (Cettia brunnifrons), with which it may be mistaken; however in all observations from Manipur, India the Tsweep calls were interspersed with Tzick clicking or grating calls; the latter is not known to be produced by Gray-sided Bush Warbler. Caution is advised in separating the two species based on Tsweep calls alone.

Geographic Variation

None documented and more study needed.

Phenology

Little known. In the wintering grounds, it is known to vocalize and utter calls occasionally, and its behaviour is usually shy and skulking. Primary call Tzick is the most commonly heard call in winter, given in various contexts, usually when foraging, when it is given singly, in well-spaced intervals. In the breeding season, the species is relatively easier to detect and identify due to the high frequency of delivering its Primary Song consistently for long durations from prominent perches. On Emei Shan, Sichuan Province, China it has been recorded singing as low as 1,800 meters although those birds could still have been on passage (2 Kennerley, P., and D. Pearson (2010). Reed and Bush Warblers. Christopher Helm, London, UK. Close ). The Primary Song also given occasionally in winter but abruptly and inconsistently, only in the presence of conspecifics.

Daily Pattern of Vocalizing

Only anecdotal information available. In wintering grounds, the birds would give their primary call Tzick singly, in well-spaced intervals while foraging, more consistently in the early mornings and usually when foraging; but would give this call arbitrarily throughout the day. The Primary Song was also given abruptly in the early mornings, usually in the presence of conspecifics. In the breeding season, the Primary Song is delivered more consistently throughout the day, and it is known to be repeated every 2–3 seconds consistently, for long durations, usually from open, prominent perches.

Places of Vocalizing

In winter, the Primary Song and its variation (Chew-chewey-you song) are delivered from inconspicuous, well-concealed low (1–2 meters) perches in dense foliage. The birds are typically shy, skulking and very elusive in wintering grounds and difficult to observe while vocalizing. In the breeding season, the Primary Song and its variations are delivered, usually from relatively high, open, or prominent perches, making the birds relatively easier to observe while vocalizing.

Sex Differences

No information.

Repertoire and Delivery of Songs

Little information available. See Primary Song, above.

Social Context and Presumed Functions of Vocalizations

More study needed. Chew-chewey-you song variation may probably function as an alarm or warning in the wintering grounds, but may likely function as a territorial song in the breeding season. Primary call Tzick is given in various contexts as it is the most commonly heard call in winter; likely used as a contact call, but also delivered as alarm or warning to conspecifics or intruders. Tsip or Tsweep calls may also have similar functions, and are used in variety of contexts in winter, but primarily as a contact call.

None documented with communicative function.

Not globally threatened. Generally uncommon; not well known. Rare in Nepal; occurs in Royal Chitwan National Park. Local in northeastern Indian Himalayas; uncommon in Bhutan and China. Status of subspecies vafra in hill regions of northeastern India (Assam) uncertain; possibly only non-breeding visitor; further fieldwork required.

Version 1.1: Puja Sharma is an ardent birder and bird sound-recordist from India, with a background in finance and banking. She saw her first Siberian Cranes at Bharatpur Bird Sanctuary when she was 9 years old, and has been fascinated by outdoors and nature, especially birds, since she was a child. While living at her grandparents’ house in Mussoorie in the western Himalayan foothills, she found her profound love for bird sounds, and has been enthralled by bird vocalizations since. Nothing gives her more joy than birding and hiking the mighty Himalaya mountains and pointing her microphone to a bird until it has been heard (and recorded!) to speak for itself. A natural history enthusiast, she has a keen interest in studying historical bird literature, specimens, and mapping records of the birds of the Indian Subcontinent. She was involved in contributing state-first records for three states of India (Punjab, Uttarakhand, and Manipur), and recently, two country-first records for India; and rediscovering Mount Victoria Babax in Mizoram. She is part of the editorial board of Indian BIRDS journal and truly believes in making information on birds universally accessible.