The Sri Lanka Frogmouth, or Batrachostomus moniliger, is an unobtrusive bird that’s as much a mystery as it’s captivating. A denizen of the Western Ghats of South India and Sri Lanka, this species is renowned for its cryptic behaviour and ability to blend seamlessly with its surroundings. Nightjars are its closest relatives, and like them, the Sri Lanka Frogmouth is predominantly nocturnal and thrives in forest habitats. Their distinctive call is a familiar sound during the twilight hours, but spotting one is a challenging task even for the most seasoned bird watcher.
Their plumage mimics the colour and texture of dried leaves, allowing them to roost undisturbed on branches during the day. Given their preference for regular roosting spots, the elusive frogmouth can be tracked down by the dedicated bird lover. However, their appearance and behaviour make them incredibly difficult to notice, often leading to their presence being overlooked. The differentiation in the plumage of the sexes and their extraordinary roosting habits make the Sri Lanka Frogmouth an intriguing subject for ornithological study.
Table for the Sri Lanka Frogmouth:
| Serial Number | Characteristics | Description |
| 1 | Common name | Sri Lanka Frogmouth |
| 2 | Scientific name | Batrachostomus moniliger |
| 3 | Colour | Gray-brown (male), Chestnut brown (female) |
| 4 | Average length | 23 cm |
| 5 | Average height | Not applicable (Bird does not stand upright) |
| 6 | Type of bird | Forest |
| 7 | Found in India in states | Kerala, Karnataka, Goa, Maharashtra, Tamil Nadu (Western Ghats) |
| 8 | Habitat | Tropical forest with dense undergrowth |
| 9 | IUCN Status | Least Concern |
Features of the Sri Lanka Frogmouth:
Length:
The Sri Lanka Frogmouth is a small bird, measuring approximately 23 cm in length. This size makes it one of the smallest members of the frogmouth family. Despite its diminutive stature, it exhibits remarkable physical features, such as a wide, hooked bill and eyes positioned for a wide field of binocular vision. These attributes aid the bird in navigating its nocturnal lifestyle and provide it with a predatory advantage while hunting insects.
Height:
Discussing the height of the Sri Lanka Frogmouth is a challenging task. Unlike most birds, it does not perch upright but instead lies horizontally along branches while roosting. This habit, combined with its non-upright stance, makes its height not as prominent or measurable as its length. However, it’s worth noting that even when the bird is standing on the ground, it maintains a low profile, further enhancing its camouflage.
Speed:
The speed of the Sri Lanka Frogmouth, while not specifically recorded, is deemed sufficient for its lifestyle and environment. Their flight pattern is characterised as weak and fluttery but capable of manoeuvring through their forest habitats. The speed of the Sri Lanka Frogmouth becomes evident during hunting, when it has been observed to dart quickly out from its perch to catch flying insects and return to its spot almost instantaneously.
Unique Physical Features:
One of the remarkable characteristics of the Sri Lanka Frogmouth is its superb camouflage, made possible by its unique physical features. Its grayish-brown to chestnut-brown plumage, depending on the sex, perfectly mimics dried leaves, enabling the bird to blend with its surroundings seamlessly. The male bird’s plumage displays fine barring and a spotted crown, while the female’s plumage exhibits very fine black speckles.
Habitat and Food of the Bird:
- The Sri Lanka Frogmouth inhabits tropical forests, particularly those with dense undergrowth. The Western Ghats of southwest India and certain regions of Sri Lanka provide such habitats.
- It can adapt to disturbed habitats, often seen in plantations and secondary forests. Its survival in such disturbed habitats shows its adaptability and resilience.
- This bird species is predominantly nocturnal, becoming active at dusk and hunting throughout the night.
- The Sri Lanka Frogmouth feeds primarily on insects, employing two main hunting strategies – sallying and gleaning. It flies out from its perch to catch insects mid-air (sallying) or picks off insects from the ground or tree branches (gleaning).
- The bird’s diet is diverse, consisting of a variety of insects, including beetles, moths, and other small invertebrates. Its broad and hooked bill is perfectly suited for snapping up its prey.
Nesting and Nurturing:
The breeding season of the Sri Lanka Frogmouth coincides with the end of the dry season and the beginning of the monsoons, typically from January to April in southern India and February to March in Sri Lanka. This bird constructs a small, pad-like nest out of moss, camouflaged with lichens and bark on the outside. The nest is usually built on a thin, horizontal branch, often at the junction of a branch with the tree trunk.
The female lays a single white egg, which both parents take turns to incubate. Remarkably, the male often assumes brooding duties during the day, while both parents share the task at night. The incubation period lasts for about 30 days. Once the chick hatches, both parents participate in feeding and protecting it until it is ready to fledge.
Threads:
Although the Sri Lanka Frogmouth’s status under the IUCN Red List is classified as ‘Least Concern’, it faces several threats that could impact its population stability. These include habitat loss due to deforestation, human encroachment, and conversion of forest lands for agriculture or development purposes. Despite its adaptability to disturbed habitats, significant loss of primary forest habitats could prove detrimental for the species.
Predation is another potential threat to the Sri Lanka Frogmouth, particularly during the nesting stage. Given their single-egg clutch, any predation event can significantly impact reproductive success. Moreover, the use of pesticides in plantations and forests may affect the bird’s insect prey, indirectly impacting their food availability and survival.
Finally, climate change could pose a long-term threat to the Sri Lanka Frogmouth. The temperature and rainfall patterns may have an impact on the living conditions of various species of animals, as well as their access to food supplies. This could potentially result in changes to their distribution range or a decrease in their population.
IUCN Status and Conservation:
The International Union for Conservation of Nature (IUCN) lists the Sri Lanka Frogmouth as ‘Least Concern’. This categorisation suggests that the species is widely distributed and does not currently face a significant threat of extinction. However, this status should not lead to complacency, as the species could be vulnerable to rapid environmental changes.
Conservation efforts for the Sri Lanka Frogmouth should focus primarily on habitat preservation. Protecting the forest habitats, particularly in the Western Ghats and Sri Lanka, is crucial for ensuring the survival of the species. Given the bird’s sensitivity to habitat alteration, environmental impact assessments should be undertaken before approving development projects in these areas.
Furthermore, research and monitoring should be promoted to better understand the species’ population dynamics, breeding biology, and potential threats. .Raising public awareness through initiatives could help emphasize the significance of this distinct species and its contribution in preserving ecological stability.
