1/5/2024 0 Comments Bird wing alula![]() ![]() Pickledog's picture to the right shows the serrations to the cutting edge of the beak of a greylag goose, quite a few wildfowl have this adaptation to facilitate the handling of foodstuff, vegetation in geese but in others (mergansers etc) it may be fish. Tomium/Tomia The cutting edge of the beak, in some wildfowl this can be serrated, in raptors there can be a notch in the upper mandible known as the Tomial tooth, this is used to sever the spinal cord of prey items. The ears are asymmetrically positioned on the skull in most owls, one is higher up than the other, the vertical disparity along with the horizontal displacement (one on each side of the head) allows the bird to fix the position of a sound very accurately. ![]() The facial disc in owls is very important in their hunting strategy as it forms a 'sound scoop' to channel sounds to the ears which are located roughly below the rim. The rim is the dark feathering that marks the edge of the facial disc, which the photo on the left shows very well. The iris is the coloured part of the eye surrounding the pupil, in some bird's of prey iris colour can be used to age or sex the bird. The bristles are formed of bare feather shafts it is difficult to find information specific to owls, but for birds in general,īristles around the mouth is thought to provide either sensory input to locate a prey properly when getting the bill close, or to provide protection against onslaught by prey. The eyebrows are again formed of feathers rather than body parts and and form due to the junction of the facial feathering and the head feathering. The ear tufts are merely feathers that can be erected when the bird is agitated for some reason and will lay flat when the bird is calm, they have no auditory function at all as the birds ears are located elsewhere. The owl (right) shows several features that are almost unique to owls. This means that the bird would only be able to tell that a sound was coming from one side or the other but not whether it was in front or behind. Just a straight forward hole leading to the ear drum. Usually this would be covered by feathers and thus be invisible. Which may or may not be different to the surrounding feathers, the lore is the area between the eye and beak whilst the ear coverts (also known as auriculars) are the feathers covering the ear opening.ĭucbucin’s photo of the Bullock’s Oriole (top right) shows quite vividly the ear opening in relation to the eye of the bird. The two enclosed areas show the position of feather groups, The coronal area is the area of the crown covered by the medial and lateral crown/coronal stripes. Lots of birds will show only 1 or 2 of the stripes. The crown stripes (median, lateral, supercilium and eye) and the cheek stripes (moustachial, sub-moustachial and malar) are shown in order to familiarize the reader with their relative positions, In this generalized passerine head (right) you can see several features that may not all be distinguishable on a real bird. ![]()
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