In ornithology, the facial disc is the concave collection of feathers on the face of some birds—most notably owls—surrounding the eyes. The concavity of the facial disc forms a circular paraboloid that collects sound waves and directs those waves towards the owl's ears.

2006年5月24日 · Barn owls are well known for their conspicuous ruff. The ruff serves as a sound collector (Payne 1971; Coles and Guppy 1988) and is important for sound localization. After ruff-feather removal major errors in elevational sound localization were …

Barn owls have a characteristic facial ruff, which improves sound localization (Keller et al. 1998, Hausmann et al. 2009). The ruff undergoes massive growth during the 60 days following hatching (Haresign and Moiseff 1988, Köppl et al. 2005).

2019年4月9日 · A facial ruff (a ring of stiff feathers) form a curved wall around an owl’s face that acts like a reflector for sound. The ruff increases the surface area over which sound is collected, increasing sound sensitivity by about 20 decibels.

Barn-owl chicks are altricial and scantily feathered when they hatch. Growth of the head and ruff feathers occur at separate times during early maturation. Between II and 30 days after hatching, the diameter of the head approximately doubles. Between 35 and 60 days, facial ruff feathers emerge and grow to nearly adult length (ca. 20 ram).

In all owl species, the facial plumage forms a parabolic dish, the facial ruff, which is most conspicuous in the the barn owl (Tyto alba). The center of the ruff is formed by auricular feathers. Such feathers are also found on the preaural flaps which cover the …

2009年11月5日 · HRTFs in the barn owl ( Tyto alba) are also shaped by the facial ruff, a specialization that alters interaural time differences (ITD), interaural intensity differences (ILD), and the frequency spectrum of the incoming sound to improve sound localization.

HRTFs in the barn owl (Tyto alba) are also shaped by the facial ruff, a specialization that alters interaural time differences (ITD), interaural intensity differences (ILD), and the frequency spectrum of the incoming sound to improve sound localization.

2009年11月5日 · HRTFs in the barn owl (Tyto alba) are also shaped by the facial ruff, a specialization that alters interaural time differences (ITD), interaural intensity differences (ILD), and the frequency spectrum of the incoming sound to improve sound localization.

Owls have large heads, and many species have a complete or partial facial ruff of stiff, sound-reflective feathers that acts as an effective sound collector (Fig. 14.1). In addition, the ears of some owls are oriented asymmetrically in the vertical plane, which gives them the ability to perceive both the azimuth and elevation of a sound source ...