Bulbuls are slim, long-tailed passerines. All of them perch in an angular posture and are usually good singers. They can be quite gregarious when in large groups, especially when feeding. Bulbuls build a bowl-shaped nest out of thin sticks, and their nests are quite neat and tidy. A clutch usually consists of two eggs.
There are roughly 150 species of bulbuls, mainly found in Africa and Asia. Karnataka is home to 8 species of bulbuls, and all these species can be found within a 250-kilometre radius from Bangalore.
The Red-whiskered Bulbul is usually the first bird to arouse the curiosity of most people, given that it is quite common in cities and very tolerant of human presence. It is a slim, dark-backed, conspicuous bulbul with a long crest, which is often held upright giving it a very smart appearance. It has red face patches, lending it its name. It also has a red vent like the Red-vented Bulbul, but the two species differ in their head shape, head colour, and red face patch. An opportunistic feeder, the Red-whiskered Bulbul feeds on fruit, nectar, flower buds and invertebrates. Red-whiskered Bulbuls are native from India to southeast China to northern Malaya.
In contrast to the Red-whiskered Bulbul, the Red-vented Bulbul has a short crest, giving the head a squarish appearance. The head is also dark and blackish in colour. As its name suggests, this bird has a red vent, and its black tail is tipped white. Red-vented Bulbuls feed on a diet of fruits, nectar, flower petals, insects, and occasionally, geckos. Red-vented Bulbuls are native from Pakistan to southwest China.
The Yellow-throated Bulbul is a range-restricted species, which favours rocky scrub forests. The bird was first described by TC Jerdon in 1844, from Horsley Hills in Andhra Pradesh. It is one of the few bulbuls to nest in rock cliffs and is usually seen in pairs. Though possible to confuse it with the White-browed Bulbul (their range overlaps and calls are similar), it is easily recognisable by its distinctively yellow head, throat and vent. The diet of the Yellow-throated Bulbul consists of berries and insects. This species is endemic to southern India and is threatened with extinction due to habitat loss. Berry-bearing shrubs, particularly Securinega, Toddalia, Erythroxylon, Solanum, Santalum, Ziziphus, Ficus, Canthium, Phyllanthus and Lantana, are important food sources.
Of all the bulbuls found in Karnataka, the White-browed Bulbul has to be the loudest in its vocalisations. It shares a similar habitat to the Yellow-throated Bulbul, but has a larger range and is more common. The White-browed Bulbul has olive upperparts, whitish underparts, and a white supercilium which gives it its name. It prefers dense scrub and feeds on fruit, nectar and insects. This species is endemic to southern India and Sri Lanka.
The Grey-headed Bulbul prefers moist broad-leaved evergreen forests with bamboo and dense undergrowth. This species was originally described by TC Jerdon. Its plumage is olive green, and it has a grey head, nape and throat; its forehead is yellow-green. It has a sharp, single-note call unlike other bulbuls. It can be extremely shy and is rarely seen in the open. Its diet consists mainly of fruits and invertebrates. Fruits include those of Symplocos cochinchinensis, Antidesma menasu, Clerodendrum viscosum, Syzygium cumini, Litsea floribunda, Maesa indica, Callicarpa tomentosa, Leea indica and Lantana camara. The Grey-headed Bulbul is a Western Ghats endemic.
Having moved to Coorg recently, I usually take a morning walk on the family coffee plantation and enjoy the bird-life there. One such morning, I noticed a flurry of activity on a Jackfruit Tree. On closer inspection, it turned out to be a group of Grey-headed Bulbuls. They were intent on feeding on the white, sticky sap oozing out of the tree. This came as a surprise, since I have never before seen any birds showing interest in this sap; perhaps they were feeding on insects that were stuck in the sap.
While birding in the dense forests of the Western Ghats, the calls of the Yellow-browed Bulbul seem to follow you everywhere. This is a brightly coloured bird – olive above and yellow below – with prominent large, dark eyes and a yellow eyebrow. This species was originally described by TC Jerdon in 1839, on the basis of specimens from the Wayanad region. Yellow-browed Bulbuls frequent sholas, evergreen forests, and shade-grown coffee plantations. They feed mostly on fruits and seeds as well as spiders and a variety of winged insects. They are usually found in mixed flocks along with Fulvettas, Black-naped Monarchs and many other species, as they move through the forest canopy. Their nest is a cup built in a low tree fork, covered with moss and cobwebs on the outside. The Yellow-browed Bulbul is native to southern India and Sri Lanka.
Originally described by John Gould in 1835, the Flame-throated Bulbul is the most striking of all the bulbuls, with its black head, orange-red throat, and white iris. This species is endemic to the Western Ghats and is primarily a bird of the forest, rarely seen in coffee plantations. The Flame-throated Bulbul feeds on fruit and insects, sometimes in mixed-species foraging flocks. Its breeding season is mostly from February to April. The nest is a small cup, placed in the undergrowth, 1 to 3 metres from the ground level, and is usually made of yellowing leaves bound with cobwebs; it can easily be mistaken for a wind-blown accumulation of dry leaves.
The Square-tailed Bulbul is quite gregarious, and is found in groups, feeding noisily on fruiting and flowering trees. This species was originally described by Sykes in 1832. Usually found at higher elevations compared to the other bulbuls, its natural habitat is subtropical or tropical moist montane forests. This black coloured bulbul has a striking orange-red beak. The Square-tailed Bulbul is native to south-western India and Sri Lanka.