Shy and unapproachable, Hume’s Leaf Warbler ( Phylloscopus humei) comes into our city in September, from the Himalayas, where it breeds, and stays until about March or April.
This warbler is named after Allan Octavian Hume, a British Civil Servant in colonial India and a notable ornithologist and botanist who is often known as the Father (sometimes the Pope) of Indian Ornithology. He was an avid collector of bird specimens for ornithological study and research, and also the founder of the journal Stray Feathers , where he and his subscribers kept notes on birds from across India for reference.
The Hume’s Leaf Warbler is strongly arboreal in nature, meaning, it mostly keeps to trees, thus contributing to its elusive nature. It is one of the smallest warblers and is greyish-olive on top and has off-white underparts with a yellow tinge. There is a pale white supercilium (an eyebrow of sorts), two wingbars (markings on the wing), and a yellow rump patch (above the tail). It also exhibits crown stripes, and well-marked flight feathers, a short and slightly forked square tail, a black bill, and dark and slender legs.
Leaf-warblers comprise of several species, many of which are very similar in appearance to each other and are difficult to identify. Although found in a variety of habitats and at a range of altitudes, they are forest-dwelling birds and inhabit the tree canopy. Some species feed on the ground, others in shrubs. They are often difficult to see through the thick canopy foliage, flitting from branch to branch, rarely undertaking long flights in the open, only making an exception when out looking for water.
The Hume’s Leaf Warbler has a distinct buzzing and high-pitched call (two-note chizip chizip ), distinguishing itself from the other types of Warblers that also find their way into the city during the winter months.
They are found individually or in small flocks with other similar-sized species of birds outside of breeding period.
They are active and on rare occasions can be seen fluttering from their preferred canopy to catch insects. If you’re observant, you can see them hopping, twisting, jumping and sidling in the foliage. They are extremely restless birds, frequently twitching their wings and flicking their tails.
There are certain species like this one, that do not believe in showing themselves, but have no qualms about being vocal in their presence. The thrill of straining the ear for that sound makes up for the bird’s apparent physical absence.
The writer is the founder of NINOX - Owl About Nature, a nature-awareness initiative. He is the Delhi-NCR reviewer for Ebird, a Cornell University initiative, monitoring rare sightings of birds. He formerly led a programme of WWF India.
