Top 20 Most Common Bird in Sikkim

This whistling thrush is dark violet blue with shiny spangling on the tips of the body feathers other than on the lores, abdomen and under the tail. The wing coverts are a slightly different shade of blue and the median coverts have white spots at their tips. The bill is yellow and stands in contrast. The inner webs of the flight and tail feathers is black. The sexes are similar in plumage. It measures 31–35 cm (12–14 in) in length. Weight across the subspecies can range from 136 to 231 g (4.8 to 8.1 oz). For comparison, the blue whistling thrush commonly weighs twice as much as an American robin. This species is possibly the largest extant thrush though size overlap does occur with the similar by length great thrush and the insular Amami thrush, whose mean body mass falls around the middle of those of the whistling thrush. Among standard measurements, the wing chord can measure 15.5–20 cm (6.1–7.9 in) long, the tarsus is 4.5–5.5 cm (1.8–2.2 in) and the bill is 2.9–4.6 cm (1.1–1.8 in). Size varies across the range with larger thrushes found to the north of the species range and slightly smaller ones to the south, corresponding with Bergmann's rule. In northern China, males and females average 188 g (6.6 oz) and 171 g (6.0 oz), whereas in India they average 167.5 g (5.91 oz) and 158.5 g (5.59 oz). Several populations are given subspecies status. The nominate form with a black bill is found in central and eastern China. The population in Afghanistan, turkestanicus, is often included in the widespread temminckii which has a smaller bill width at the base and is found along the Himalayas east to northern Burma. The population eugenei, which lacks white spots on the median coverts, is found south into Thailand. Cambodia and the Malay peninsula have crassirostris, while dichrorhynchus with smaller spangles occurs further south and in Sumatra. The Javan population, flavirostris, has the thickest bill. The subspecies status of several populations has been questioned.

The red-vented Bulbul is considered a pest by gardeners as it eats fruits and vegetables and spreads seeds to non-native regions. Because of this, these bird is considered an invasive species in some countries. The red-vented Bulbul is loud and can become aggressive to other birds and even humans in their forest, shrubland, and urban habitats.

The rufous sibia (Heterophasia capistrata) is a species of bird in the family Leiothrichidae. It feeds on berries and insects. It is found in the northern parts of the Indian subcontinent, ranging across India, Nepal and Bhutan. Its natural habitat is the temperate forests of the Lower to Middle Himalayas. The species has an unmistakable appearance with its rufous-dominated colouration and black head, and is often seen with its crest raised. It is a vigorous, melodious singer.

The green-backed tit (Parus monticolus) is a species of bird in the family Paridae. It is found in Bangladesh, Bhutan, China, India, Laos, Burma, Nepal, Pakistan, Taiwan and Vietnam. Its natural habitats are boreal forest, temperate forest, and subtropical or tropical moist lowland forest.

The oriental Turtle-dove is a migratory bird whose appearance can vary between subspecies. Individuals from higher latitudes migrate south over the winter months while those at lower latitudes do not migrate. The oriental Turtle-dove can be found in a large range of habitats, but usually prefers dense tree coverage. These birds mainly forage for seeds on the ground.

The Himalayan bulbul is about 18 cm in length, with a wingspan of 25.5–28 cm and an average weight of 30 g. Its head, throat, and crest are black and white. The back, side, and lengthy tail are brown, the underside is pale yellow. Sexes have similar plumage. The song is a beautiful 4-piece whistle, which resembles an accelerated oriole whistle.

The grey-hooded warbler (Phylloscopus xanthoschistos) is a species of leaf warbler (family Phylloscopidae). It is most famous for the way it warbles. It was formerly included in the "Old World warbler" assemblage. It is found in the Himalayas. Its natural habitat is temperate forests.

The common Myna is a large, stocky starling that prefers to live near humans in towns and suburban areas. It forages among tall grasses for grasshoppers; in fact, its scientific name, Acridotheres tristis, means "grasshopper hunter." The common Myna likes to maintain two roosts at the same time - both a temporary summer roost near the breeding site as well as a year-round roost where the female can sit and brood.

The grey treepie is 36–40 cm (14–16 in) long and weighs 89–121 g (3.1–4.3 oz). It is the same size as other Dendrocitta species and is separated from them by the overall grey colour of the body. The races in the western part of the distribution have a greyish rump and some grey in tail while the eastern forms have a white rump and a black tail. The face and throat are dark and black with a diffuse mask. The body is grey on the underside becoming whiter towards the vent. The back and scapulars are brownish. The crown and nape are greyish and the black wing has a prominent white carpal patch. The vent is rufous and the outer tail feathers and tips of the central feathers are black. The beak is black, the legs are blackish-brown and the eyes are red or reddish-brown. The two sexes are similar. The juvenile bird is duller, with a browner nape, and all of its feathers have rufous tips. The species occupies a large geographical range and has several recognised regional forms that differ slightly from one another for instance in colour and tail length. These include occidentalis of the western Himalayan foothills (identified by its slightly longer tail), himalayana from the central Himalayas east into Thailand and Vietnam. A disjunct population, said to have a smaller or narrower bill, is found in the Eastern Ghats of peninsular India, sarkari, that is sometimes subsumed into himalayana. The Southeast Asian races include assimilis, sapiens, sinica, formosae (the nominate race from Taiwan) and insulae (Hainan Island). It has been suggested that this species forms a superspecies along with Dendrocitta occipitalis and Dendrocitta cinerascens.

The great barbet has a blue head, large yellow bill, brown and green-streaked body, belly and a red vent. The plumage is green. It is the largest barbet species with a body length of 32–35 cm (13–14 in) and a weight of 192–295 g (6.8–10.4 oz).

Both genders are black with red underparts and white crown atop their heads. Males have a larger white pattern on top of the head and brown or red spots under the wings. It is found in the Indian Subcontinent and Southeast Asia, as well as some adjoining areas. The species ranges across Afghanistan, Bangladesh, Bhutan, Cambodia, India, Laos, Myanmar, Nepal, Tajikistan, Thailand, Tibet and Vietnam. Its natural habitat is temperate forests. This species was formerly placed in the monotypic genus Chaimarrornis but was moved to Phoenicurus based on the results of a molecular phylogenetic study published in 2010.

The grey-headed canary-flycatcher is about 12–13 cm (4.7–5.1 in) long with a squarish grey head, a canary yellow belly and yellowish-green upperparts. They forage actively like flycatchers and perches in a very upright posture. The sexes are indistinguishable in plumage. They have a very flat bill (which gave it the earlier genus name of Platyrhynchus) which when seen from above look like an equilateral triangle and is fringed with long rictal bristles. Across their range, populations differ in the shades of the colours and vary slightly in dimensions and several of these have been designated as subspecies. The nominate subspecies breeds in peninsular India in the hills of the Western Ghats, Nilgiris, central India and the Eastern Ghats (Lammasingi) and Sri Lanka. Subspecies calochrysea first described by Harry Oberholser in 1923 breeds along the Himalayas east to Myanmar and Thailand and winters across southern India. The nominate form is darker in shade. Subspecies antioxantha which was also described by Oberholser has a breeding range from southern Burma, Thailand through Malaysia to Java and Bali. The island population sejuncta described by Ernst Hartert in 1897 is found on Sumbawa, Flores and possibly on Lombok while connectens described by Bernhard Rensch in 1931 is restricted to the island of Sumba. The grey-headed canary-flycatcher was earlier considered to be an Old World flycatcher in spite of its odd crest, colours and nature of vocalization. Molecular phylogeny studies however show that they are quite different and have been placed in the family Stenostiridae that is closely related to the tits and penduline-tits.

The leiothrix is about six inches in length, generally olive green, and has a yellow throat with orange shading on the breast. It also has a dull yellowish ring around the eye that extends to the beak. The edges of the wing feathers are brightly colored with yellow, orange, red and black and the forked tail is olive brown and blackish at the tip. The cheeks and side of the neck are a bluish gray color. The female is a lot paler than the male and lacks the red patch on the wings. It doesn't fly frequently, except in open habitats. This bird is very active and an excellent singer but very secretive and difficult to see.

The chestnut-crowned laughingthrush (Trochalopteron erythrocephalum) is a species of bird in the family Leiothrichidae. It is found in Bhutan, China, India, and Nepal. The silver-eared laughingthrush, formerly included as a subspecies, is now usually regarded as a separate species.

The overall size (length: 46–59 cm; 18–23 in.) and body proportions vary regionally. In the far northeast in Japan, the Kuriles and the Sakhalin peninsula, it is somewhat larger than the carrion crow. All taxa have a relatively long bill with the upper one quite thick and arched, making it look heavy and almost raven-like. Generally, all taxa have dark greyish plumage from the back of the head, neck, shoulders and lower body. Their wings, tail, face, and throat are glossy black. The depth of the grey shading varies across its range.

The adult ashy drongo is mainly dark grey, and the tail is long and deeply forked, There are a number of subspecies varying in the shade of the grey plumage. Some subspecies have white markings on the head. Young birds are dull brownish grey. Subspecies longicaudatus of India (which includes beavani of the Himalayas that winters on the peninsula, with one breeding population in central India that Vaurie separates as longicaudatus in the restricted sense) is very dark and almost like the black drongo although this bird is slimmer and has a somewhat longer and less-splayed tail. It is found in more tall forest habitat, has dark grey underside lacking the sheen of black drongo. The iris is crimson and there is no white rictal spot. Subspecies leucogenis and salangensis have a white eye-patch as do several of the island forms that breed further south. The calls are a little more nasal and twangy than that of the black drongo.

The russet sparrow is a small chunky bird, with plumage warm rufous in overall colour. It is a medium-sized sparrow at 14 to 15 cm (5.5–5.9 in) and 18 to 22.5 grams (0.63–0.79 oz). It has a thick bill suited to eating seeds, which is black on the breeding male, horn-coloured on the non-breeding male, and yellowish with a dark tip on the female. Wingspans for males range between 6.8 to 8.2 cm (2.7–3.2 in) and those for females from 6.7 to 7.7 cm (2.6–3.0 in). Tail, bill, and tarsus lengths are 4.3 to 5.1 cm (1.7–2.0 in), 1.1 to 1.3 cm (0.43–0.51 in), and 1.6 to 1.8 cm (0.63–0.71 in), respectively. Measurements for the russet sparrow vary geographically, between the three subspecies, and also within the Himalayan subspecies cinnamomeus. The subspecies cinnamomeus is generally larger than the others, and within this form there is a tendency for birds at higher altitudes to be larger, and a clinal variation in size with the smallest birds in the west of the range and the largest in the east. The iris is chestnut in colour. The legs of both sexes are pale brown to pinkish-brown. The flight of all sparrows is swift, and that of the russet sparrow is described as swifter and more direct than that of the Eurasian tree sparrow.

The whiskered yuhina (Yuhina flavicollis) is a bird species in the white-eye family Zosteropidae. Its range extends across the Himalayan forests in northern India to northeast Indian states, Nepal, Bhutan, Bangladesh and in the east to Indochina including Laos, Myanmar, Thailand, and Vietnam. Its natural habitat is subtropical or tropical moist montane forests. The whiskered yuhina is sometimes found in mixed hunting parties with other yuhina and fulvetta species, but it has also been reported to not associate with mixed hunting parties in some areas. It is described as one of the commonest yuhinas in the Himalayas, although it is relatively uncommon to rare at low elevations. It prefers relatively undisturbed closed canopy cover. It is one among several other birds hunted by livestock herders in Northeast India.

The blue-fronted redstart (Phoenicurus frontalis) is a species of bird in the family Muscicapidae, the Old World flycatchers. It breeds in central China and the Himalayas (where it winters in the southern foothills, as well as in Yunnan, Northeast India and northern Southeast Asia). Its natural habitat is temperate forests. The female is brownish-grey, with paler underparts.

The black bulbul is 24–25 cm (9.4–9.8 in) in length, with a long tail. The body plumage ranges from slate grey to shimmering black, depending on the race. The beak, legs, and feet are all orange and the head has a black fluffy crest. Sexes are similar in plumage, but young birds lack the crest, have whitish underparts with a grey breast band, and have a brown tint to the upperparts. They have a black streak behind the eye and on the ear coverts.