The Indian blue whistling thrush (Myophonus horsfieldii) is a beautiful bird found across parts of South and Southeast Asia. Known for its distinctive whistling call and brilliant blue plumage, the Indian blue whistling thrush has captured the fascination of many ornithologists and birdwatchers. In this article, we will explore the key facts about this species, including its taxonomy, physical description, distribution, habitat, diet, breeding habits, conservation status, and cultural significance.
Taxonomy
The Indian blue whistling thrush belongs to the genus Myophonus within the muscicapidae family of small passerine birds. Its scientific name is Myophonus horsfieldii. Here is a quick overview of its taxonomy:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Passeriformes
- Family: Muscicapidae
- Genus: Myophonus
- Species: M. horsfieldii
There are four recognized subspecies of the Indian blue whistling thrush which vary slightly in size and coloration depending on their geographic range:
- Myophonus horsfieldii horsfieldii – found in northwestern India
- Myophonus horsfieldii malabaricus – found in southern India
- Myophonus horsfieldii intermedius – found in northeastern India and Bangladesh
- Myophonus horsfieldii whistleri – found in Sri Lanka
Physical Description
The Indian blue whistling thrush is a medium-sized songbird, measuring around 28 cm (11 inches) in length. Here are some key physical features:
- Bright electric blue plumage on the head, back, wing coverts and tail
- Blackish blue plumage on the throat and breast
- Blue-grey legs and feet
- Black bill with yellow base
- Dark brown irises
- Distinct white malar stripe below the eye
- Females tend to be slightly duller in color than males
- Juveniles have duller blue plumage with brown scaling
The brilliant blue plumage of the male Indian blue whistling thrush is iridescent and appears to change shade depending on the lighting. This striking coloration makes the bird easy to identify in the wild.
Distribution and Habitat
The Indian blue whistling thrush has a wide distribution across parts of South and Southeast Asia. Its breeding range extends through:
- Northwestern and peninsular India
- Sri Lanka
- Southern China
- Myanmar
- Thailand
- Laos
- Vietnam
- Malaysia
- Sumatra and Java
During the winter, the species migrates from higher elevations to lower areas across its range. The Indian blue whistling thrush can be found up to altitudes of 2,400 meters in the Himalayas during summer.
This species inhabits dense forest and jungle habitats near streams and rivers. It prefers areas with rocky outcrops, overhanging cliffs, caves and gorges. Proximity to water is key as it often bathes and drinks from mountain streams.
Diet
The Indian blue whistling thrush is an omnivorous bird with a diverse diet. Its key food sources include:
- Insects – caterpillars, beetles, grasshoppers, crickets
- Other invertebrates – snails, worms, millipedes
- Small reptiles – lizards, frogs
- Fish
- Berries
- Seeds
- Small mammals
- Eggs and nestlings of other birds
It often perches on rocks in the middle of streams, waiting patiently to ambush aquatic prey like small fish and frogs swimming by. The Indian blue whistling thrush will also forage on the forest floor among leaf litter for insects and worms.
Breeding and Nesting
The breeding season for the Indian blue whistling thrush depends on its geographic location:
- Northern India – April to July
- Southeast Asia – February to June
- Sri Lanka – Mainly January to May
During courtship, the male will sing its loud whistling song from prominent perches to attract a mate. Once paired, the female will construct a nest in a rock crevice, hole in a tree, or niche on a cliff face up to 12 meters above the ground.
The nest is cup-shaped and made from moss, roots, grass and mud. It is lined with fine grass, hair and feathers. The female lays a clutch of 3-5 pale blue eggs and incubates them alone for 13-14 days before they hatch.
Both parents feed the chicks, which fledge from the nest around 14-16 days after hatching. The young birds will remain dependent on the parents for several more weeks as they learn to hunt and forage on their own.
Call and Song
As its name suggests, the Indian blue whistling thrush is best known for its melodious whistling call. Its most common vocalization is a loud, descending whistle, often transliterated as “pseet-pseet-pseet-pseet”.
This whistling call serves several functions:
- Communicating over long distances
- Defending breeding territories
- Maintaining contact with mate
- Begging calls by young
The species also has a warbling song given by the male during the breeding season. This intricate song has fluty musical phrases that ascends and descends in pitch and tempo.
Behavior and Movement
The Indian blue whistling thrush is generally observed singly or in pairs, rarely forming larger flocks. It can often be found perched upright on rocks and boulders near flowing water, scanning for prey.
Despite its bulky size, the thrush is quite agile and can hop and run swiftly across wet rocky surfaces. It is an excellent climber and will readily nest and roost in steep cliffs and gorges.
When threatened, it will freeze upright with crest raised, sometimes flicking its tail. Under persistent disturbance, it will fly off with rapid wingbeats to another perch.
The species is territorial during breeding but may join mixed-species foraging flocks in the non-breeding season.
Threats and Conservation
The Indian blue whistling thrush has a wide distribution and large overall population, estimated at 100,000 to 1 million individuals. While still relatively common, its numbers are slowly declining across parts of its range due to the following threats:
- Habitat loss and degradation from deforestation
- Disturbance to rocky riverine habitats from hydroelectric projects and mining
- Nest predation from rats, snakes and monkeys
- Hunting at some locations for food and medicinal use
However, the species remains classified as Least Concern on the IUCN Red List due to its large range and population. Targeted conservation actions include protecting key breeding habitats and reducing nest predation near human settlements.
Significance to Humans
The Indian blue whistling thrush is admired and respected across its native range for its remarkable plumage and habitat. In Sri Lanka, it is revered as the national bird and even appears on some currency notes.
The species also has cultural importance in Buddhism. It is said to have been a previous life of the Buddha, and its blue color symbolizes Buddhist wisdom and truth.
For many nature-lovers, this thrush is considered one of the most beautiful birds in Asia. Birdwatchers eagerly seek out its wild jungle habitats for a chance to observe its striking colors and hear its musical call.
Key Facts Summary
Here are some key facts to recap about the Indian blue whistling thrush:
- Scientific name: Myophonus horsfieldii
- Medium-sized thrush reaching 28 cm in length
- Brilliant blue plumage in males, slightly duller in females
- Found from northern India to Southeast Asia
- Inhabits rocky forests and gorges near water
- Omnivorous diet includes insects, fish and fruit
- Notable loud whistling call
- Builds nests on rock cliffs and crevices
- Sri Lankan national bird and sacred in Buddhism
- Classified as Least Concern but numbers slowly declining
Conclusion
With its memorable melodic call and gorgeous iridescent plumage, the Indian blue whistling thrush has rightfully earned a special place in the hearts of nature enthusiasts across its range. Although still relatively common, continued habitat conservation efforts are needed to ensure the long-term survival of this beloved songbird. The striking beauty and musical voice of the Indian blue whistling thrush will hopefully continue inspiring awe in forests across South and Southeast Asia for generations to come.
