The Javan scops owl (Otus angelinae ) is a small species of owl living mainly in western Java's high volcanos; local people refer to the owl as Celepuk Jawa. Like most owls, this nocturnal bird also has a strong ability of silent flight.
The average weight of this bird species is 75-90 grams with a body length of 160-180mm. It has a small tail (63-69 mm) but large wings (135-149 mm) to accommodate its lengthy sliding distance. The O.Angelinae has a light rusty-brown facial disc and prominent white brows that extend into ear tufts (of). Their hooked bill is 19.5-21.5mm long and varies in colour from dark straw-yellow to light greyish-yellow. The upper part of their body is brown or rufous-brown, generally, with a rusty-buff hindneck-collar, whitish scapular stripe and remiges barred. The underpart of their body is white to pale buff with a pronounced black streak superimposed on light rufous vermiculations. These brown feathers striated with black and white spots help them to better camouflage into the environment. One can distinguish O.Angelinae from O.spilocephalus by noticing their more golden yellow or orange-yellow irides, prominent white eyebrows and ear tufts and tarsal feathering over the base of the toes.
These birds are endemic to West Java's highland forest. Their tracks were discovered in the mountains of Mount Salak, Mount Pangrango, Mount Gede, and Mount Tangkuban Perahu; their appearances were also historically reported in the Papandayan and Ciremay areas.
The Javan scops owl prefers montane forest with a well-developed understory at elevations ranging from 1500 to 2000m. Their documented living elevation ranges from 900 to 2500 metres. They preferred to dwell in the lower and middle canopy layers with a broader variety of tree species.
Insects like beetles, grasshoppers, crickets and mantis comprise the main portion of their diet. There have been reports of tiny lizards and snakes being consumed occasionally.
Javan scops owl can deliver beetles (Coleoptera), mantids (Mantodea), stick insect (Phasmatodea), grasshoppers (Tettigoniidae, Orthoptera), and crickets (Gryllidae, Orthoptera) to feed the fledged offspring. In terms of foraging, they use their keen vision and acute hearing to track down their prey and snare it from the trunk, foliage, or the ground.
Three family units with two newly fledged young were reported in previous literature, one in early February and the other two in early July. Based on these observations, laying is predicted to occur in the second weeks of December and May, respectively, and the clutch size is most likely two eggs.
The Javan scops owl is listed as vulnerable on the IUCN Red List. Its activity range is limited to the forests of Java and Bali. While it is considered rare by most authors, it is somewhat more common in the montane forest above 1,400m on Mount Salak. Its secretive behaviour and silent habits make the estimation of the bird population very difficult. This species' worldwide population is estimated to be between 1500 and 1700 individuals, with a declining tendency owing to forest fragmentation.
