Introduction
The Solomons Frogmouth (Rigidipenna inexpectata) is a nocturnal, forest-dwelling frogmouth endemic to the northern Solomon Islands. It was described scientifically in 1901, but its distinctiveness was not fully recognised until a 2007 taxonomic review placed it in its own genus, Rigidipenna. The species is a member of the frogmouth family, Podargidae, and is one of the Solomon Islands’ distinctive endemic birds.
Physical Description
The Solomons Frogmouth is a medium-sized frogmouth with predominantly brown, buff and grey-brown plumage that provides effective camouflage among branches and foliage. Its broad bill and large gape are characteristic of frogmouths. The iris may be yellow, pale orange-yellow, yellowish-brown or brown, while the bill is typically brown to reddish-brown and the gape is pale lemon.
The species has eight tail feathers, rather than the ten found in the other frogmouth genera. Its outer tail feathers are coarse, while the central feathers are broad, stiff and rounded at the tips. These unusual tail features are reflected in the genus name Rigidipenna, which refers to stiff feathers.
Males generally have darker dorsal plumage than females and are, on average, larger, although the sexes overlap considerably in size. Published specimen measurements show wing lengths of approximately 19.5–23.4 cm and tail lengths of approximately 16.0–19.0 cm. Reliable information on age-related plumage differences is limited.
Range and Habitat
The Solomons Frogmouth is endemic to the northern Solomon Islands. Confirmed records include Bougainville and Buka in Papua New Guinea, and Choiseul, Santa Isabel and San Jorge in Solomon Islands. The species was formerly treated as a subspecies of the Marbled Frogmouth, but morphological, skeletal and molecular evidence supports its recognition as a separate species and genus.
It occurs in primary forest and secondary growth, including forest near gardens. Records extend from coastal and lowland areas into hill forest, with documented observations at about 500 m elevation and more recent records reaching at least 700 m. The species is considered monotypic, and the available evidence does not establish consistent geographic variation in size or plumage between islands.
Behaviour and Diet
The Solomons Frogmouth is nocturnal and arboreal. It is generally associated with forested habitats and is likely to remain motionless on branches during the day, relying on its cryptic plumage for concealment. Detailed observations of its daily activity, social behaviour and movements remain scarce.
Its vocalisations are poorly known but include short whistles that rise in pitch and descending series of whistles repeated in quick succession. These calls can be useful for detecting the species in dense forest, where visual encounters are difficult.
The diet has not been documented in sufficient detail to describe it confidently. Like other frogmouths, it is likely to take animal prey, particularly arthropods, but species-specific feeding observations are limited and should not be overstated.
Breeding information is also sparse. One recorded nest was a shallow stick platform placed on a horizontal fork approximately 25 m above the ground in the canopy of a tall secondary-forest tree. The nest contained an almost fledged young bird.
Identification Tips
- Look for a medium-sized, brown and buff frogmouth in forest or secondary growth, especially after dark.
- The broad bill and large gape are typical frogmouth features.
- The plumage is strongly camouflaged, with brown, buff and grey-brown tones that blend with bark and branches.
- The call may consist of rising whistles or a short descending series of whistles repeated in quick succession.
- The species can be distinguished from the Marbled Frogmouth by its broader bill, distinctive stiff central tail feathers and, where known, its restricted northern Solomon Islands range.
- Because the species is rarely seen and its vocalisations are incompletely documented, identification should be based on a combination of appearance, call and location rather than on a single feature.
Conservation Status
The Solomons Frogmouth is currently assessed as Near Threatened on the IUCN Red List. It has a restricted island distribution and depends on forest and secondary forest habitats. Forest clearance, logging and agricultural expansion are therefore important conservation concerns because they can reduce and fragment suitable habitat.
The species’ population size and trend are not sufficiently documented for a reliable global estimate. Conservation priorities include protecting remaining forest, maintaining habitat connectivity, supporting sustainable land use and improving surveys of distribution, abundance, vocalisations, breeding and diet. Records from local communities and field surveys are particularly valuable because the bird is difficult to detect and remains poorly known.
Frequently Asked Questions
Where does the Solomons Frogmouth live?
It occurs in the northern Solomon Islands, including Bougainville and Buka in Papua New Guinea, and Choiseul, Santa Isabel and San Jorge in Solomon Islands. It inhabits primary forest and secondary growth from lowland areas into hill forest.
Is the Solomons Frogmouth a true frogmouth?
Yes. It belongs to the frogmouth family, Podargidae. It is the only recognised species in the genus Rigidipenna.
When was the Solomons Frogmouth discovered?
The bird was first described from a specimen collected in 1901. It was recognised as a distinct species and placed in the new genus Rigidipenna following a taxonomic study published in 2007.
What does the Solomons Frogmouth eat?
Its precise diet is poorly documented. It is probably an animal-prey specialist, as are other frogmouths, but published species-specific feeding observations are limited.
Is the Solomons Frogmouth endangered?
It is not currently classified as Endangered, but the IUCN lists it as Near Threatened. Its restricted range and dependence on forest make habitat loss and degradation important concerns.
How can the Solomons Frogmouth be identified in the field?
Useful clues include its broad bill, cryptic brown and buff plumage, nocturnal habits, restricted northern Solomon Islands range and distinctive rising or descending whistle sequences. It is often easier to detect by call than by sight.
References
- Cleere, N., Kratter, A. W., Steadman, D. W., Braun, M. J., Huddleston, C. J., Filardi, C. E. and Dutson, G. 2007. A new genus of frogmouth (Podargidae) from the Solomon Islands, results from a taxonomic review of Podargus ocellatus inexpectatus Hartert 1901. Ibis 149(2): 271–286. https://doi.org/10.1111/j.1474-919X.2006.00626.x
- Woxvold, I. A. and Novera, J. 2021. Birds of conservation concern and other notable birds of Bougainville, Papua New Guinea. Bulletin of the British Ornithologists’ Club 141(2): 211–236. Available at https://bioone.org/journals/bulletin-of-the-british-ornithologists-club/volume-141/issue-2/bboc.v141i2.2021.a14/Full-Issue/10.25226/bboc.v141i2.2021.a14.pdf. Accessed 8 September 2026.
- del Hoyo, J., Collar, N., Garcia, E. F. J. and BirdLife International. 2020. Solomons Frogmouth (Rigidipenna inexpectata), version 1.0. In Birds of the World. Cornell Lab of Ornithology. https://doi.org/10.2173/bow.soifro1.01
- BirdLife International. 2020. HBW-BirdLife Taxonomic Checklist of the Birds of the World, version 5.0. BirdLife DataZone. Available at https://datazone.birdlife.org/about-our-science/taxonomy. Accessed 8 September 2026.
- Gill, F., Donsker, D. and Rasmussen, P. 2026. IOC World Bird List, version 15.2. International Ornithologists’ Union. Available at https://www.worldbirdnames.org/. Accessed 8 September 2026.
- International Union for Conservation of Nature. 2020. The IUCN Red List of Threatened Species, assessment information for the Solomons Frogmouth (Rigidipenna inexpectata), Near Threatened. Conservation status reported through BirdLife International, the IUCN Red List Authority for birds. Available at https://datazone.birdlife.org/. Accessed 8 September 2026.
- Smith, B. T., Arcila, D., Tauxe, L., Stidham, T. A., Bravo, G. A., Burney, C. W., Manthey, J. D., Weir, J. T., Mauck, W. M., Chaves, J. A., Aleixo, A., Hosner, P. A., Cuervo, A. M., Cadena, C. D. and others. 2020. Oligocene divergence of frogmouth birds (Podargidae) across Wallace’s Line. Proceedings of the Royal Society B: Biological Sciences 287: 20200531. https://doi.org/10.1098/rspb.2020.0531
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