Large-tailed Nightjar (Caprimulgus macrurus) – A Comprehensive Study

Taxonomy & Classification

• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• Order: Caprimulgiformes
• Family: Caprimulgidae
• Genus: Caprimulgus
• Species: Caprimulgus macrurus

The Large-tailed Nightjar (Caprimulgus macrurus) belongs to the family Caprimulgidae, which includes nocturnal insectivorous birds known for their cryptic plumage and silent flight. This species is widely distributed across South and Southeast Asia, including India, Bangladesh, Thailand, Malaysia, and Indonesia.

Morphology & Physical Description

• Size: 25–30 cm in length
• Wingspan: 55–65 cm
• Weight: 65–98 grams
• Plumage: Highly camouflaged with brown, grey, and buff patterns, resembling dried leaves or tree bark.
• Head Features: A broad, flattened head with large, dark eyes adapted for night vision.
• Beak: Small and slightly hooked but with a wide gape that aids in catching insects during flight.
• Legs & Feet: Short and weak, adapted more for perching than walking.
• Tail: Long and slightly rounded, with white markings on the outer feathers (more prominent in males).

Habitat & Distribution

The Large-tailed Nightjar is a highly adaptable species found in a variety of environments, including:

• Tropical and subtropical forests
• Mangrove forests and coastal woodlands
• Scrublands, grasslands, and open clearings
• Plantations and agricultural fields

Presence in the Sundarban

In the Sundarban, the Large-tailed Nightjar thrives in:

• Mangrove fringes and dense undergrowth, where it roosts during the day.
• Open clearings and forest edges, where it hunts for insects at night.
• Coastal grasslands and sandy patches, providing excellent camouflage.

This species is a year-round resident of the Sundarban, benefiting from the rich insect population found in this biodiverse ecosystem.

Feeding Behavior & Diet

The Large-tailed Nightjar is an aerial insectivore, primarily feeding on:

• Moths, beetles, grasshoppers, and flying ants
• Termites and other small nocturnal insects
• Occasionally, it catches small crustaceans near coastal areas.

Foraging Strategy

• Hunts at dusk and dawn (crepuscular activity), using its large eyes for low-light vision.
• Uses silent flight and a wide gape to snatch insects mid-air.
• Often hunts near water bodies, taking advantage of insect swarms.

Breeding & Nesting

• Breeding Season: March to September, peaking before the monsoon.
• Nest Location: Ground nests in leaf litter, sand, or forest clearings.
• Eggs: Usually two eggs per clutch, colored to match the ground for camouflage.
• Parental Care: Both parents share incubation (18–21 days) and chick-rearing.

Unlike most birds, nightjars do not build nests. They rely on camouflage to protect their eggs from predators like monitor lizards, snakes, and larger birds.

Vocalization & Communication

The Large-tailed Nightjar is best identified by its distinct call, which is often heard at night:

• A repetitive “chonk-chonk-chonk” sound, especially during mating season.
• Soft purring or grunting sounds when disturbed.

Its calls serve as territorial signals and courtship displays.

Special Adaptations

1. Nocturnal Lifestyle: Excellent night vision and silent flight make it an efficient nighttime hunter.
2. Cryptic Camouflage: Blends perfectly with the forest floor, avoiding predators.
3. Aerial Insect Hunting: Adapted to snatch insects mid-flight using its wide mouth and bristle-like feathers.
4. Minimalist Nesting Strategy: Reduces the risk of detection by nesting directly on the ground without building elaborate nests.

Threats & Conservation Status

• Habitat loss due to deforestation, coastal development, and human disturbance.
• Predation of eggs and chicks by snakes, lizards, and feral animals.
• Light pollution, which disrupts its natural hunting patterns.

IUCN Status: Least Concern (LC)

Despite localized threats, the Large-tailed Nightjar remains widespread and adaptable, ensuring its continued survival in diverse habitats, including the Sundarban.

Conclusion

The Large-tailed Nightjar (Caprimulgus macrurus) is a fascinating nocturnal bird that plays a vital role in controlling insect populations in the Sundarban ecosystem. Its stealthy nature, cryptic plumage, and unique vocalizations make it a remarkable yet elusive species. Continued conservation of mangrove forests and minimizing human disturbances will help sustain its population in this fragile environment.