White-throated Needletail (Hirundapus caudacutus) – A Comprehensive Study
Taxonomy & Classification
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Apodiformes
- Family: Apodidae
- Genus: Hirundapus
- Species: Hirundapus caudacutus
The White-throated Needletail (Hirundapus caudacutus), also known as the Spine-tailed Swift, is one of the fastest birds in level flight. It belongs to the Apodidae family, which includes swifts, birds highly adapted to aerial life.
Morphology & Physical Description
- Size: 19–21 cm in length
- Wingspan: 50–56 cm
- Weight: 110–120 grams
- Plumage:
- Upperparts are dark brown with a metallic sheen
- Underparts have a distinct white throat and belly, contrasting with darker flanks
- Head Features:
- Broad, slightly flattened head with a short but wide beak
- Large, dark eyes suited for aerial navigation
- Beak: Short but strong, adapted for catching insects in flight
- Legs & Feet: Extremely short; adapted for clinging to vertical surfaces rather than walking
- Tail: Features rigid needle-like tail feathers, aiding in stability during flight
Habitat & Distribution
The White-throated Needletail is a highly aerial species, preferring:
- Mountainous regions, open woodlands, and coastal cliffs
- Tropical and subtropical regions, often found in hilly terrain and river valleys
- Migratory Range:
- Breeds in central and eastern Asia, Russia, and Siberia
- Winters in South and Southeast Asia, including India and Australia
Presence in the Sundarban
The Sundarban, with its vast intertidal mangrove ecosystem, is not a primary breeding habitat for the White-throated Needletail, but it serves as an important stopover site during migration.
- Seen during autumn and spring migration while traveling between breeding and wintering grounds
- Occasionally sighted above mangrove forests, feeding on insects carried by coastal winds
- Prefers the open skies above river deltas, estuaries, and forest clearings
Feeding Behavior & Diet
The White-throated Needletail is an insectivorous species, relying on:
- Flying insects like beetles, moths, dragonflies, and ants
- Occasionally feeds on small spiders carried by air currents
Foraging Strategy
- Aerial hunting: Captures prey in mid-flight, often at high speeds
- Feeds in flocks, especially during migration
- Uses rapid turns and dives to catch insects with precision
Breeding & Nesting
- Breeding Season: May to July (in northern breeding range)
- Nest Sites:
- Prefers tree hollows, cliff crevices, and sometimes man-made structures
- Unlike other swifts, does not nest in caves
- Eggs: Lays 2–3 white eggs per clutch
- Parental Care:
- Both parents incubate the eggs (about 25 days)
- Chicks fledge within 6–8 weeks, becoming independent quickly
Vocalization & Communication
The White-throated Needletail produces:
- High-pitched chattering calls during flight
- Soft whistles used in social interactions and during flock movements
Special Adaptations
- Fastest Level-flying Bird: Capable of reaching speeds up to 170 km/h (106 mph).
- Aerial Mastery: Can stay airborne for months, feeding, drinking, and even sleeping in flight.
- Needle-like Tail Feathers: Help in stability and maneuvering during high-speed flight.
- Highly Efficient Wings: Long, swept-back wings reduce drag, allowing sustained gliding.
Threats & Conservation Status
- Deforestation and habitat loss reduce breeding sites
- Declining insect populations due to pesticides impact food availability
- Climate change alters migration patterns and weather conditions affecting survival
IUCN Status: Least Concern (LC)
Although globally not endangered, monitoring is necessary as habitat degradation can affect local populations. Protecting migratory corridors, including the Sundarban, is crucial.
Conclusion
The White-throated Needletail (Hirundapus caudacutus) is an extraordinary migratory swift, built for speed and agility. Though not a resident of the Sundarban, its seasonal presence highlights the region’s importance as a vital stopover for migratory birds. Conservation of mangrove forests and open flight corridors is essential to support species like this during their long journeys.