Special Adaptions

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Adaptions – Hunting

The barn owl has evolved special adaptions so that when hunting:
  • It’s wings are silent as it flies along and it’s specialised ears pick up the sound of prey moving about below.
  • It uses it’s strong wings to slow down and may for a moment hover whilst it’s powerful eyes are fixed upon the unsuspecting prey.
  • To lose height quickly the owl tucks its wings upwards and plunges towards its prey and then brings its powerful talons forwards ready to close on it’s victim
  • As the owl is about to grab its prey it closes its eyes and relies solely on its hearing.
  • It grabs its prey with a force which will probably kill it immediately.
  • If the owl has only a short distance to fly it will carry its prey in its beak otherwise it will more often carry its prey in its talons until it arrives at it’s resting spot or nest site.
  • If the prey is large or there are small owlets to feed it will use it’s strong hooked beak to tear the prey into smaller pieces, otherwise it will swallow it whole.

Adaptions – Vision

The eyes of barn owls are important to the bird’s ability to fly and hunt in the dark and the proportionately large eyes with large pupils are obviously a help with this. In addition the retina at the back of each eye is packed with more low light sensitive cells than most other birds. The disadvantage of this is that barn owls can only see in black and white and although their vision is superb, detailed research reveals that the differences between barn owl vision and that of other animals is not as startling as was once supposed, although they are far more sensitive than the eyes most diurnal birds.

Unlike most birds, the eyes of barn owls are fixed in their sockets and are forward facing set in the large heart shaped facial disk. This arrangement means that there is a large blind area behind the head but provides a wide area of binocular vision in front. The blind area is not really a disadvantage as the bird has a very flexible neck that allows it to rotate it’s head through 300 degrees.

Adaptions – Hearing

The hearing of barn owls is extremely good because:
  •  The external openings to the ears which are positioned on the margins of the facial disk are of slightly different size and one ear is slightly higher than the other.
  • There is a stiff line of feathers that forms the edge the facial disk and these reflect sound towards the ears.
  • The ear openings are protected by adjustable flaps which combined with the other features allow the barn owl to judge the source of rustless and squeaks on the ground with a high degree of accuracy.

Experiments have shown that a barn owls hearing is an essential complement to its vision when it comes to its nocturnal lifestyle and when hunting in particular as it can locate its prey in complete darkness by sound alone.

Adaptions- Wings

Compared to most other birds barn owls have wings with a surface area that is extremely large relative to their body weight. These long, large wings are also broad and rounded and the combination of these features allow them to fly at relatively low speeds with apparantly little effort.
 

The wings of the barn owl have another very important adaption – the leading edge and the outer part of the trailing edge of thier flight feathers have stiffened barbs and the upper surfaces are downy – these special feathers provide silent flight. Silent flight is important for two reasons, firstly their prey cannot hear the barn owl approaching and secondly, the barn owl’s sensitive hearing is not compromised by unwanted wing noise.

Adaptions – Feet

The feet of the barn owl are similar to those of most birds of prey and are essential for successful hunting as they are used as weapons to kill their prey and as a means of carrying it when flying to it’s feeding spot or nesting site.

The legs are long and powerful with widely spreading feet equipped with long, deadly sharp talons. The prey is often killed by the initial impact and insertion of the talons though sometimes assistance is required from the sharp hooked beak to swiftly finish the the job. The outer toe on each foot is reversible to help with the capture of its prey and to enable the owl to keep a good hold of it when flying. The undersides of their feet are rough which also helps with gripping prey.