Friday, 10 August 2012

Hunting High And Low

Although I find most birds endlessy fascinating, there always seems to be something particularly magical about catching a glimpse of a bird of prey – whether it’s watching a sparrowhawk that’s just landed in my back garden, or seeing buzzards catching some thermals in the air above me.

But what makes birds of prey so good at, well, being birds of prey? Below I let you into a few of the secrets that make birds of prey top predators.
Barn Owl
Heart-faced assassin

Barn owls have the keenest sense of hearing of any known animal. By just listening, they can calculate exactly where a noise is coming from, helping them catch some 2,000 mice, voles and small animals every year!

Their secret? Having a face shaped like a satellite dish and ears that are positioned ever so slightly askew from each other.

As sound waves hit their dish-shaped face the sound is channelled into their ears allowing them to work out the direction that the noise is coming from. Kind of handy when most of your prey likes to remain hidden in vegetation.
Keen-eyed Kestrel
Another bird of prey whose prey would also rather stay out of sight is the kestrel. But rather than hearing, a kestrels main weapon is its eyesight.

Voles are a much-preferred meal for kestrels, and while they might be small and difficult to see when scurrying about under long grass, that poses no problem to a kestrel.

Voles and other small rodents lay scent trails of urine and faeces, both of which reflect ultraviolet (UV) light. And while UV light is invisible to you and I, kestrel are able to see it.

Bad news for small mammals, great for kestrels looking for their next meal!

Not so slippery customer
Having spotted a fish from 30 m up in the air, an ospreys next meal doesn’t really stand a chance.

With (nearly always) perfect accuracy, ospreys take a near vertical plunge dive towards the water with wings half-folded and feet thrown forward at the last moment plucking the chosen fish clean out the water.

While you could probably have guessed that ospreys have great eyesight, have you ever wondered what other weapons they have to help keep slippery fish in their grasp?

Well, ospreys have big feet and an opposable toe, allowing them to get a firm grip on their catch, while sharp spines on their feet give extra grip.

To protect themselves as they hit the water, ospreys also have a patch of dense feathers on their chest. Pretty neat!

Fast living
Clocking up speeds of nearly 200mph when in a hunting ‘stoop’, peregrines are one fast bird.

But being able to hit such top speeds wouldn’t be of much use if you couldn’t breathe! As you would expect, peregrines have that covered.

To protect their lungs from the damaging change in air pressure such a feat produces, small growths on their nostrils change the airflow and reduce the pressure experienced, making breathing easier!

Peregrines also have a third eyelid which allows them to clean their eyes while still being able to still see! Definitely useful when you move at such speeds.

What other techniques do birds of prey use? Do let me know in the comments below, as I’m sure I’ll have missed some…