Silky-tailed Nightjar vs Heinrich's Nightjar
Antrostomus sericocaudatus compared with Eurostopodus diabolicus
Side-by-Side Comparison
| Attribute | Silky-tailed Nightjar | Heinrich's Nightjar |
|---|---|---|
| Scientific Name | Antrostomus sericocaudatus | Eurostopodus diabolicus |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Caprimulgidae | Caprimulgidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 32.1 cm (12.6 in) | 39.9 cm (15.7 in) |
| Weight | 77.5 g (2.73 oz) | 104.0 g (3.67 oz) |
| Diet | Hawks moths and beetles in nocturnal aerial sallies over South American lowland and foothill forest. | Nocturnal aerial insectivore; catches moths and beetles in flight over Sulawesi forest; poorly known. |
| Clutch Size | 2 | 1 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Silky-tailed Nightjar
Whistled, rolling 'pwee-pwee-pwee'; melodic phrase from Amazonian forest; calls persistently at dusk; slightly slurred delivery; alarm a sudden sharp note
Heinrich's Nightjar
Haunting, hollow 'ku-WOO' repeated rhythmically; deep resonant quality; distinctive mournful whistle carrying through Sulawesi forest at night
Geographic Range & Migration
Silky-tailed Nightjar
Resident of lowland and foothill forest in southern Brazil (São Paulo, Minas Gerais, Santa Catarina) and adjacent Paraguay and Argentina.
Heinrich's Nightjar
Endemic to Sulawesi, Indonesia; resident of montane forest; extremely rare and poorly known, with very few records.
Conservation Status
Silky-tailed Nightjar
Heinrich's Nightjar
How to Tell Them Apart
Silky-tailed Nightjar
Brown and buff mottled above with dark vermiculations; white gorget in male; outer tail feathers with silky-white inner webs giving smooth appearance; pale buff below; female with buff gorget and …
Heinrich's Nightjar
Rufous-brown and dark brown mottled with buff vermiculations; large pale buff throat patch; pale buff supercilium; no white wing markings; tail darkly barred brown and buff. Poorly known; Sulawesi endemic.
About These Birds
Silky-tailed Nightjar
A medium Caprimulgidae nightjar (~78 g) of humid lowland Atlantic Forest and adjacent cerrado edges in central and southeastern Brazil and adjacent Paraguay. Named for its silky-textured outer tail feathers. Cryptic brown plumage. Nocturnal insectivore. Rarely recorded; biology little known. Least Concern.
Heinrich's Nightjar
A medium Caprimulgidae nightjar (~104 g) endemic to the forest and forest-edge habitats of Sulawesi, Indonesia. Cryptically patterned brown-and-buff. Nocturnal insectivore; catches moths and beetles in aerial sallies. Little studied and rarely encountered in the field. Least Concern within its Sulawesi range.