Master of Disguise:
The Sri Lanka Frogmouth

 

By: Savio Fonseca

 

    I was bird-watching with a Portuguese couple through the Bhagwan Mahaveer National Park in Goa a part of the dense Western Ghats forest one bright afternoon. Our local guide led us along a path occasionally blocked by fallen trees or low-hanging branches, requiring us to stoop to pass through. Eventually, we reached a dense patch of undergrowth, where the guide pointed out a pair of birds and exclaimed, “There they are!”

The Portuguese couple peered into the undergrowth, puzzled and unable to see the birds. We tried using hand gestures to indicate their location, but it was futile. Speaking was not an option, as we feared disturbing the roosting birds, though it was evident that words would not have been helpful in this situation anyway.

Finally, the man set up his camera on a tripod, and I offered to focus the lens on the birds. Only then did he and his wife grasp the extent of the birds’ camouflage. They were visibly astonished and bewildered, struggling to spot the birds with their eyes outside the camera’s viewfinder.

The Sri Lanka Frogmouth Batrachostomus moniliger, a bird even expert birdwatchers find challenging to detect, had taken them by surprise. Despite their extensive experience identifying bird species worldwide, the couple was amazed at how seamlessly this bird blends into its surroundings. In my opinion, the Sri Lanka Frogmouth is one of nature’s masters of disguise, mimicking leaves, bark, and even lichens with remarkable precision.

This bird’s camouflage is even more impressive. In a light breeze, it subtly sways to mimic leaves trembling in the wind. Its nest, constructed on a short hollow stump, perfectly blends within the environment making it almost invisible. This exceptional adaptation makes it difficult for experienced birdwatchers, let alone casual observers who may only recognize a few bird species.

A nocturnal bird about the size of a myna, the Sri Lanka Frogmouth inhabits dense evergreen forests at elevations ranging from sea level to 1,200 m in India and up to 1,800 m in Sri Lanka. While it prefers undisturbed forests, it can adapt to secondary forests and small wooded areas near human settlements.

During the day, it roosts on branches in shady spots, typically 2–6 m above the ground, hidden among the foliage. Sri Lanka Frogmouth hunt for insects in the night, capturing them mid-air, picking them off the ground, or gleaning them from tree surfaces. Their distinctive calls – loud, screeching cries interspersed with chuckling notes – are most often heard at dusk and dawn. Once thought to be rare and restricted to a small range, recent observations have revealed a much wider distribution. However, their incredible camouflage makes it difficult to accurately assess population sizes and trends.

Male and female Sri Lanka Frogmouths exhibit noticeable differences in plumage. Males are predominantly greyish-brown, while females have a greyish-rufous coloration. Both have large heads, wide bills with hooked tips, and bristles around the eyes and bill – typical characteristics of frogmouths. Compared to other members of their family, their wings are shorter and more rounded.

Their markings are intricate and functional. The belly and sides display white spots, and the throat is adorned with white dots resembling an unfinished collar, which mimic lichen patterns on bark. Males exhibit prominent black patches on the head, vermiculated patterns on the belly, and grey bands on the tail and flight feathers, while females have a more uniform rufous tone with fewer black markings and less pronounced barring.

Sri Lanka Frogmouths are commonly found in undisturbed forests with secondary vegetation, often comprising deciduous species such as Schleichera trijuga, Lagerstroemia microcarpa, Terminalia bellerica, and Terminalia tomentosa. Specific habitats, such as bamboo forests with Solanum and Strobilanthes undergrowth, have been identified as particularly suitable. Other habitats include evergreen forests with trees like Carallia, Polyalthia, Mesua, Myristica, Alseodaphne, and Garcinia.

Despite having documented 33 sightings of this bird across Maharashtra, Goa, Karnataka, and Kerala, it remains one of the most elusive species to spot using traditional birding techniques. Professional guides often rely on recorded calls to attract the birds and then locate them using minimal light.

On one occasion, I flushed out a Sri Lanka Frogmouth during a daytime birding trip in Netravali Wildlife Sanctuary while searching for a Grey-headed Bulbul. Such encounters are rare. The typical approach for finding these birds involves night-time expeditions with recorded calls, though this can pose risks, especially in habitats where venomous reptiles like Russell’s Vipers, Hump-nosed Pit Vipers, Malabar Pit Vipers, Spectacled Cobras, and King Cobras are present.

Professional guides employ specialized techniques to locate these birds at night while minimizing disturbance to both the birds and their environment. By using minimal lighting and careful observation, they balance the isolation and conservation needs of this extraordinary species. 

■ Savio Fonseca is an author, photographer, naturalist, data contributor, and conservationist.